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多年iOS开发经验总结(二)

壹峰
 壹峰
发布于 2017/07/11 11:07
字数 6284
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1、设置UILabel行间距

NSMutableAttributedString* attrString = [[NSMutableAttributedString  alloc] initWithString:label.text];
    NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
    [style setLineSpacing:20];
    [attrString addAttribute:NSParagraphStyleAttributeName value:style range:NSMakeRange(0, label.text.length)];
    label.attributedText = attrString;

// 或者使用xib,看下gif图

Untitled.gif

2、当使用-performSelector:withObject:withObject:afterDelay:方法时,需要传入多参数问题

// 方法一、
// 把参数放进一个数组/字典,直接把数组/字典当成一个参数传过去,具体方法实现的地方再解析这个数组/字典
NSArray * array = 
    [NSArray arrayWithObjects: @"first", @"second", nil];
[self performSelector:@selector(fooFirstInput:) withObject: array afterDelay:15.0];

// 方法二、
// 使用NSInvocation
SEL aSelector = NSSelectorFromString(@"doSoming:argument2:");
    NSInteger argument1 = 10;
    NSString *argument2 = @"argument2";
    if([self respondsToSelector:aSelector]) {
        NSInvocation *inv = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:aSelector]];
        [inv setSelector:aSelector];
        [inv setTarget:self];
        [inv setArgument:&(argument1) atIndex:2];
        [inv setArgument:&(argument2) atIndex:3];
        [inv performSelector:@selector(invoke) withObject:nil afterDelay:15.0];
    }

3、UILabel显示不同颜色字体

NSMutableAttributedString * string = [[NSMutableAttributedString alloc] initWithString:label.text];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0,5)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(5,6)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(11,5)];
label.attributedText = string;

4、比较两个CGRect/CGSize/CGPoint是否相等

if (CGRectEqualToRect(rect1, rect2)) { // 两个区域相等
        // do some
    }
    if (CGPointEqualToPoint(point1, point2)) { // 两个点相等
        // do some
    }
    if (CGSizeEqualToSize(size1, size2)) { // 两个size相等
        // do some
    }

5、比较两个NSDate相差多少小时

 NSDate* date1 = someDate;
 NSDate* date2 = someOtherDate;
 NSTimeInterval distanceBetweenDates = [date1 timeIntervalSinceDate:date2];
 double secondsInAnHour = 3600;
// 除以3600是把秒化成小时,除以60得到结果为相差的分钟数
 NSInteger hoursBetweenDates = distanceBetweenDates / secondsInAnHour;

6、每个cell之间增加间距

// 方法一,每个分区只显示一行cell,分区头当作你想要的间距(注意,从数据源数组中取值的时候需要用indexPath.section而不是indexPath.row)
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return yourArry.count;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return 1;
}
-(CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
    return cellSpacingHeight;
}

// 方法二,在cell的contentView上加个稍微低一点的view,cell上原本的内容放在你的view上,而不是contentView上,这样能伪造出一个间距来。

// 方法三,自定义cell,重写setFrame:方法
- (void)setFrame:(CGRect)frame
{
    frame.size.height -= 20;
    [super setFrame:frame];
}

7、播放一张张连续的图片

// 加入现在有三张图片分别为animate_1、animate_2、animate_3
// 方法一
    imageView.animationImages = @[[UIImage imageNamed:@"animate_1"], [UIImage imageNamed:@"animate_2"], [UIImage imageNamed:@"animate_3"]];
imageView.animationDuration = 1.0;
// 方法二
    imageView.image = [UIImage animatedImageNamed:@"animate_" duration:1.0];
// 方法二解释下,这个方法会加载animate_为前缀的,后边0-1024,也就是animate_0、animate_1一直到animate_1024

8、加载gif图片

推荐使用这个框架 FLAnimatedImage

9、防止离屏渲染为image添加圆角

// image分类
- (UIImage *)circleImage
{
// NO代表透明
UIGraphicsBeginImageContextWithOptions(self.size, NO, 1);
// 获得上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();
// 添加一个圆
CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
// 方形变圆形
CGContextAddEllipseInRect(ctx, rect);
// 裁剪
CGContextClip(ctx);
// 将图片画上去
[self drawInRect:rect];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}

10、查看系统所有字体

// 打印字体
for (id familyName in [UIFont familyNames]) {
    NSLog(@"%@", familyName);
    for (id fontName in [UIFont fontNamesForFamilyName:familyName]) NSLog(@"  %@", fontName);
}
// 也可以进入这个网址查看 http://iosfonts.com/

11、获取随机数

NSInteger i = arc4random();

12、获取随机数小数(0-1之间)

#define ARC4RANDOM_MAX      0x100000000
double val = ((double)arc4random() / ARC4RANDOM_MAX);

13、AVPlayer视频播放完成的通知监听

[[NSNotificationCenter defaultCenter] 
      addObserver:self
      selector:@selector(videoPlayEnd)
      name:AVPlayerItemDidPlayToEndTimeNotification 
      object:nil];

14、判断两个rect是否有交叉

 if (CGRectIntersectsRect(rect1, rect2)) {
}

15、判断一个字符串是否为数字

NSCharacterSet *notDigits = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
    if ([str rangeOfCharacterFromSet:notDigits].location == NSNotFound)
    {
      // 是数字
    } else
    {
      // 不是数字
    }

16、将一个view保存为pdf格式

- (void)createPDFfromUIView:(UIView*)aView saveToDocumentsWithFileName:(NSString*)aFilename
{
    NSMutableData *pdfData = [NSMutableData data];
    UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil);
    UIGraphicsBeginPDFPage();
    CGContextRef pdfContext = UIGraphicsGetCurrentContext();
    [aView.layer renderInContext:pdfContext];
    UIGraphicsEndPDFContext();

    NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);
    NSString* documentDirectory = [documentDirectories objectAtIndex:0];
    NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:aFilename];
    [pdfData writeToFile:documentDirectoryFilename atomically:YES];
    NSLog(@"documentDirectoryFileName: %@",documentDirectoryFilename);
}

17、让一个view在父视图中心

child.center = [parent convertPoint:parent.center fromView:parent.superview];

18、获取当前导航控制器下前一个控制器

- (UIViewController *)backViewController
{
    NSInteger myIndex = [self.navigationController.viewControllers indexOfObject:self];

    if ( myIndex != 0 && myIndex != NSNotFound ) {
        return [self.navigationController.viewControllers objectAtIndex:myIndex-1];
    } else {
        return nil;
    }
}

19、保存UIImage到本地

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *filePath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Image.png"];

[UIImagePNGRepresentation(image) writeToFile:filePath atomically:YES];

20、键盘上方增加工具栏

UIToolbar *keyboardDoneButtonView = [[UIToolbar alloc] init];
[keyboardDoneButtonView sizeToFit];
UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:@"Done"
                                                               style:UIBarButtonItemStyleBordered target:self
                                                              action:@selector(doneClicked:)];
[keyboardDoneButtonView setItems:[NSArray arrayWithObjects:doneButton, nil]];
txtField.inputAccessoryView = keyboardDoneButtonView;

21、copy一个view

因为UIView没有实现copy协议,因此找不到copyWithZone方法,使用copy的时候导致崩溃
但是我们可以通过归档再解档实现copy,这相当于对视图进行了一次深拷贝,代码如下

id copyOfView = 
[NSKeyedUnarchiver unarchiveObjectWithData:[NSKeyedArchiver archivedDataWithRootObject:originalView]];

22、在image上绘制文字并生成新的image

UIFont *font = [UIFont boldSystemFontOfSize:12];
    UIGraphicsBeginImageContext(image.size);
    [image drawInRect:CGRectMake(0,0,image.size.width,image.size.height)];
    CGRect rect = CGRectMake(point.x, point.y, image.size.width, image.size.height);
    [[UIColor whiteColor] set];
    [text drawInRect:CGRectIntegral(rect) withFont:font]; 
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

23、判断一个view是否为另一个view的子视图

// 如果myView是self.view本身,也会返回yes
BOOL isSubView = [myView isDescendantOfView:self.view];

24、判断一个字符串是否包含另一个字符串

// 方法一、这种方法只适用于iOS8之后,如果是配iOS8之前用方法二
if ([str containsString:otherStr]) NSLog(@"包含");

// 方法二
NSRange range = [str rangeOfString:otherStr];
if (range.location != NSNotFound) NSLog(@"包含");

25、UICollectionView自动滚动到某行

// 重写viewDidLayoutSubviews方法
-(void)viewDidLayoutSubviews {
   [super viewDidLayoutSubviews];
   [self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionCenteredVertically animated:NO];
}

26、修改系统UIAlertController

// 但是据说这种方法会被App Store拒绝(慎用!)
UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"" message:@"" preferredStyle:UIAlertControllerStyleActionSheet];
    NSMutableAttributedString *hogan = [[NSMutableAttributedString alloc] initWithString:@"我是一个大文本"];
    [hogan addAttribute:NSFontAttributeName
                  value:[UIFont systemFontOfSize:30]
                  range:NSMakeRange(4, 1)];
    [hogan addAttribute:NSForegroundColorAttributeName
                  value:[UIColor redColor]
                  range:NSMakeRange(4, 1)];
    [alertVC setValue:hogan forKey:@"attributedTitle"];

    UIAlertAction *button = [UIAlertAction actionWithTitle:@"Label text" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){ }];
    UIImage *accessoryImage = [UIImage imageNamed:@"1"];
    [button setValue:accessoryImage forKey:@"image"];
    [alertVC addAction:button];
    [self presentViewController:alertVC animated:YES completion:nil];

27、判断某一行的cell是否已经显示

CGRect cellRect = [tableView rectForRowAtIndexPath:indexPath];
BOOL completelyVisible = CGRectContainsRect(tableView.bounds, cellRect);

28、让导航控制器pop回指定的控制器

NSMutableArray *allViewControllers = [NSMutableArray arrayWithArray:[self.navigationController viewControllers]];
for (UIViewController *aViewController in allViewControllers) {
    if ([aViewController isKindOfClass:[RequiredViewController class]]) {
        [self.navigationController popToViewController:aViewController animated:NO];
    }
}

29、动画修改label上的文字

// 方法一
CATransition *animation = [CATransition animation];
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    animation.type = kCATransitionFade;
    animation.duration = 0.75;
    [self.label.layer addAnimation:animation forKey:@"kCATransitionFade"];
    self.label.text = @"New";

// 方法二
[UIView transitionWithView:self.label
                      duration:0.25f
                       options:UIViewAnimationOptionTransitionCrossDissolve
                    animations:^{

                        self.label.text = @"Well done!";

                    } completion:nil];

// 方法三
[UIView animateWithDuration:1.0
                     animations:^{
                         self.label.alpha = 0.0f;
                         self.label.text = @"newText";
                         self.label.alpha = 1.0f;
                     }];

30、判断字典中是否包含某个key值

if ([dic objectForKey:@"yourKey"]) {
    NSLog(@"有这个值");
} else {
    NSLog(@"没有这个值");
}

31、获取屏幕方向

UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;

if(orientation == 0) //Default orientation 
    //默认
else if(orientation == UIInterfaceOrientationPortrait)
    //竖屏
else if(orientation == UIInterfaceOrientationLandscapeLeft)
    // 左横屏
else if(orientation == UIInterfaceOrientationLandscapeRight)
    //右横屏

32、设置UIImage的透明度

// 方法一、添加UIImage分类
- (UIImage *)imageByApplyingAlpha:(CGFloat) alpha {
    UIGraphicsBeginImageContextWithOptions(self.size, NO, 0.0f);

    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGRect area = CGRectMake(0, 0, self.size.width, self.size.height);

    CGContextScaleCTM(ctx, 1, -1);
    CGContextTranslateCTM(ctx, 0, -area.size.height);

    CGContextSetBlendMode(ctx, kCGBlendModeMultiply);

    CGContextSetAlpha(ctx, alpha);

    CGContextDrawImage(ctx, area, self.CGImage);

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return newImage;
}

// 方法二、如果没有奇葩需求,干脆用UIImageView设置透明度
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageWithName:@"yourImage"]];
imageView.alpha = 0.5;

33、Attempt to mutate immutable object with insertString:atIndex:

这个错是因为你拿字符串调用insertString:atIndex:方法的时候,调用对象不是NSMutableString,应该先转成这个类型再调用

34、UIWebView添加单击手势不响应

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(webViewClick)];
        tap.delegate = self;
        [_webView addGestureRecognizer:tap];

// 因为webView本身有一个单击手势,所以再添加会造成手势冲突,从而不响应。需要绑定手势代理,并实现下边的代理方法
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
    return YES;
}

35、获取手机RAM容量

// 需要导入#import <mach/mach.h>
mach_port_t host_port;
    mach_msg_type_number_t host_size;
    vm_size_t pagesize;

    host_port = mach_host_self();
    host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t);
    host_page_size(host_port, &pagesize);

    vm_statistics_data_t vm_stat;

    if (host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size) != KERN_SUCCESS) {
        NSLog(@"Failed to fetch vm statistics");
    }

    /* Stats in bytes */
    natural_t mem_used = (vm_stat.active_count +
                          vm_stat.inactive_count +
                          vm_stat.wire_count) * pagesize;
    natural_t mem_free = vm_stat.free_count * pagesize;
    natural_t mem_total = mem_used + mem_free;
    NSLog(@"已用: %u 可用: %u 总共: %u", mem_used, mem_free, mem_total);

36、地图上两个点之间的实际距离

// 需要导入#import <CoreLocation/CoreLocation.h>
CLLocation *locA = [[CLLocation alloc] initWithLatitude:34 longitude:113];
    CLLocation *locB = [[CLLocation alloc] initWithLatitude:31.05 longitude:121.76];
// CLLocationDistance求出的单位为米
    CLLocationDistance distance = [locA distanceFromLocation:locB];

37、在应用中打开设置的某个界面

// 打开设置->通用
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=General"]];

// 以下是设置其他界面
prefs:root=General&path=About
prefs:root=General&path=ACCESSIBILITY
prefs:root=AIRPLANE_MODE
prefs:root=General&path=AUTOLOCK
prefs:root=General&path=USAGE/CELLULAR_USAGE
prefs:root=Brightness
prefs:root=Bluetooth
prefs:root=General&path=DATE_AND_TIME
prefs:root=FACETIME
prefs:root=General
prefs:root=General&path=Keyboard
prefs:root=CASTLE
prefs:root=CASTLE&path=STORAGE_AND_BACKUP
prefs:root=General&path=INTERNATIONAL
prefs:root=LOCATION_SERVICES
prefs:root=ACCOUNT_SETTINGS
prefs:root=MUSIC
prefs:root=MUSIC&path=EQ
prefs:root=MUSIC&path=VolumeLimit
prefs:root=General&path=Network
prefs:root=NIKE_PLUS_IPOD
prefs:root=NOTES
prefs:root=NOTIFICATIONS_ID
prefs:root=Phone
prefs:root=Photos
prefs:root=General&path=ManagedConfigurationList
prefs:root=General&path=Reset
prefs:root=Sounds&path=Ringtone
prefs:root=Safari
prefs:root=General&path=Assistant
prefs:root=Sounds
prefs:root=General&path=SOFTWARE_UPDATE_LINK
prefs:root=STORE
prefs:root=TWITTER
prefs:root=FACEBOOK
prefs:root=General&path=USAGE prefs:root=VIDEO
prefs:root=General&path=Network/VPN
prefs:root=Wallpaper
prefs:root=WIFI
prefs:root=INTERNET_TETHERING
prefs:root=Phone&path=Blocked
prefs:root=DO_NOT_DISTURB

38、在UITextView中显示html文本

    UITextView *textView = [[UITextView alloc] initWithFrame:CGRectMake(20, 30, 100, 199)];
    textView.backgroundColor = [UIColor redColor];
    [self.view addSubview:textView];
    NSString *htmlString = @"<h1>Header</h1><h2>Subheader</h2><p>Some <em>text</em></p>![](http://blogs.babble.com/famecrawler/files/2010/11/mickey_mouse-1097.jpg)";
    NSAttributedString *attributedString = [[NSAttributedString alloc] initWithData: [htmlString dataUsingEncoding:NSUnicodeStringEncoding] options: @{ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType } documentAttributes: nil error: nil];
    textView.attributedText = attributedString;

39、监听scrollView是否滚动到了顶部/底部

-(void)scrollViewDidScroll: (UIScrollView*)scrollView
{
    float scrollViewHeight = scrollView.frame.size.height;
    float scrollContentSizeHeight = scrollView.contentSize.height;
    float scrollOffset = scrollView.contentOffset.y;

    if (scrollOffset == 0)
    {
        // 滚动到了顶部
    }
    else if (scrollOffset + scrollViewHeight == scrollContentSizeHeight)
    {
        // 滚动到了底部
    }
}

40、UISlider增量/减量为固定值(假如为5)

- (void)setupSlider
{
    UISlider *slider = [[UISlider alloc] init];
    [self.view addSubview:slider];
    [slider addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventValueChanged];
    slider.maximumValue = 100;
    slider.minimumValue = 0;
    slider.frame = CGRectMake(200, 20, 100, 30);
}

- (void)sliderAction:(UISlider *)slider
{
    [slider setValue:((int)((slider.value + 2.5) / 5) * 5) animated:NO];
}

41、选中textField或者textView所有文本(我这里以textView为例)

[self.textView setSelectedTextRange:[self.textView textRangeFromPosition:self.textView.beginningOfDocument toPosition:self.textView.endOfDocument]]

42、从导航控制器中删除某个控制器

// 方法一、知道这个控制器所处的导航控制器下标
NSMutableArray *navigationArray = [[NSMutableArray alloc] initWithArray: self.navigationController.viewControllers];
[navigationArray removeObjectAtIndex: 2]; 
self.navigationController.viewControllers = navigationArray;

// 方法二、知道具体是哪个控制器
NSArray* tempVCA = [self.navigationController viewControllers];

for(UIViewController *tempVC in tempVCA)
{
    if([tempVC isKindOfClass:[urViewControllerClass class]])
    {
        [tempVC removeFromParentViewController];
    }
}

43、隐藏UITextView/UITextField光标

textField.tintColor = [UIColor clearColor];

44、当UITextView/UITextField中没有文字时,禁用回车键

textField.enablesReturnKeyAutomatically = YES;

45、字符串encode编码(编码url字符串不成功的问题)

// 我们一般用这个方法处理stringByAddingPercentEscapesUsingEncoding但是这个方法好想不会处理/和&这种特殊符号,这种情况就需要用下边这个方法处理
@implementation NSString (NSString_Extended)
- (NSString *)urlencode {
    NSMutableString *output = [NSMutableString string];
    const unsigned char *source = (const unsigned char *)[self UTF8String];
    int sourceLen = strlen((const char *)source);
    for (int i = 0; i < sourceLen; ++i) {
        const unsigned char thisChar = source[i];
        if (thisChar == ' '){
            [output appendString:@"+"];
        } else if (thisChar == '.' || thisChar == '-' || thisChar == '_' || thisChar == '~' || 
                   (thisChar >= 'a' && thisChar <= 'z') ||
                   (thisChar >= 'A' && thisChar <= 'Z') ||
                   (thisChar >= '0' && thisChar <= '9')) {
            [output appendFormat:@"%c", thisChar];
        } else {
            [output appendFormat:@"%%%02X", thisChar];
        }
    }
    return output;
}

46、计算UILabel上某段文字的frame

@implementation UILabel (TextRect)

- (CGRect)boundingRectForCharacterRange:(NSRange)range
{
    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:[self attributedText]];
    NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
    [textStorage addLayoutManager:layoutManager];
    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:[self bounds].size];
    textContainer.lineFragmentPadding = 0;
    [layoutManager addTextContainer:textContainer];
    NSRange glyphRange;
    [layoutManager characterRangeForGlyphRange:range actualGlyphRange:&glyphRange];
    return [layoutManager boundingRectForGlyphRange:glyphRange inTextContainer:textContainer];
}

47、获取随机UUID

NSString *result;
    if([[[UIDevice currentDevice] systemVersion] floatValue] > 6.0)
    {
       result = [[NSUUID UUID] UUIDString];
    }
    else
    {
        CFUUIDRef uuidRef = CFUUIDCreate(NULL);
        CFStringRef uuid = CFUUIDCreateString(NULL, uuidRef);
        CFRelease(uuidRef);
        result = (__bridge_transfer NSString *)uuid;
    }

48、仿苹果抖动动画

#define RADIANS(degrees) (((degrees) * M_PI) / 180.0)

- (void)startAnimate {
    view.transform = CGAffineTransformRotate(CGAffineTransformIdentity, RADIANS(-5));

    [UIView animateWithDuration:0.25 delay:0.0 options:(UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse) animations:^ {
                         view.transform = CGAffineTransformRotate(CGAffineTransformIdentity, RADIANS(5));
                     } completion:nil];
}

- (void)stopAnimate {
    [UIView animateWithDuration:0.25 delay:0.0 options:(UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveLinear) animations:^ {
                         view.transform = CGAffineTransformIdentity;
                     } completion:nil];
}

49、修改UISearBar内部背景颜色

UITextField *textField = [_searchBar valueForKey:@"_searchField"];
textField.backgroundColor = [UIColor redColor];

50、UITextView滚动到顶部

    // 方法一
    [self.textView scrollRangeToVisible:NSMakeRange(0, 0)];
    // 方法二
    [self.textView setContentOffset:CGPointZero animated:YES];

51、通知监听APP生命周期

UIApplicationDidEnterBackgroundNotification 应用程序进入后台
UIApplicationWillEnterForegroundNotification 应用程序将要进入前台
UIApplicationDidFinishLaunchingNotification 应用程序完成启动
UIApplicationDidFinishLaunchingNotification 应用程序由挂起变的活跃
UIApplicationWillResignActiveNotification 应用程序挂起(有电话进来或者锁屏)
UIApplicationDidReceiveMemoryWarningNotification 应用程序收到内存警告
UIApplicationDidReceiveMemoryWarningNotification 应用程序终止(后台杀死、手机关机等)
UIApplicationSignificantTimeChangeNotification 当有重大时间改变(凌晨0点,设备时间被修改,时区改变等)
UIApplicationWillChangeStatusBarOrientationNotification 设备方向将要改变
UIApplicationDidChangeStatusBarOrientationNotification 设备方向改变
UIApplicationWillChangeStatusBarFrameNotification 设备状态栏frame将要改变
UIApplicationDidChangeStatusBarFrameNotification 设备状态栏frame改变
UIApplicationBackgroundRefreshStatusDidChangeNotification 应用程序在后台下载内容的状态发生变化
UIApplicationProtectedDataWillBecomeUnavailable 本地受保护的文件被锁定,无法访问
UIApplicationProtectedDataWillBecomeUnavailable 本地受保护的文件可用了

52、触摸事件类型

UIControlEventTouchCancel 取消控件当前触发的事件
UIControlEventTouchDown 点按下去的事件
UIControlEventTouchDownRepeat 重复的触动事件
UIControlEventTouchDragEnter 手指被拖动到控件的边界的事件
UIControlEventTouchDragExit 一个手指从控件内拖到外界的事件
UIControlEventTouchDragInside 手指在控件的边界内拖动的事件
UIControlEventTouchDragOutside 手指在控件边界之外被拖动的事件
UIControlEventTouchUpInside 手指处于控制范围内的触摸事件
UIControlEventTouchUpOutside 手指超出控制范围的控制中的触摸事件

53、UITextField文字周围增加边距

    // 子类化UITextField,增加insert属性
@interface WZBTextField : UITextField
@property (nonatomic, assign) UIEdgeInsets insets;
@end

// 在.m文件重写下列方法
- (CGRect)textRectForBounds:(CGRect)bounds {
    CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets);
    if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeUnlessEditing) {
        return [self adjustRectWithWidthRightView:paddedRect];
    }
    return paddedRect;
}

- (CGRect)placeholderRectForBounds:(CGRect)bounds {
    CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets);

    if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeUnlessEditing) {
        return [self adjustRectWithWidthRightView:paddedRect];
    }
    return paddedRect;
}

- (CGRect)editingRectForBounds:(CGRect)bounds {
    CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets);
    if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeWhileEditing) {
        return [self adjustRectWithWidthRightView:paddedRect];
    }
    return paddedRect;
}

- (CGRect)adjustRectWithWidthRightView:(CGRect)bounds {
    CGRect paddedRect = bounds;
    paddedRect.size.width -= CGRectGetWidth(self.rightView.frame);

    return paddedRect;
}

54、监听UISlider拖动状态

// 添加事件
[slider addTarget:self action:@selector(sliderValurChanged:forEvent:) forControlEvents:UIControlEventValueChanged];

// 实现方法
- (void)sliderValurChanged:(UISlider*)slider forEvent:(UIEvent*)event {
    UITouch *touchEvent = [[event allTouches] anyObject];
    switch (touchEvent.phase) {
        case UITouchPhaseBegan:
            NSLog(@"开始拖动");
            break;
        case UITouchPhaseMoved:
            NSLog(@"正在拖动");
            break;
        case UITouchPhaseEnded:
            NSLog(@"结束拖动");
            break;
        default:
            break;
    }
}

55、设置UITextField光标位置

// textField需要设置的textField,index要设置的光标位置
- (void)cursorLocation:(UITextField *)textField index:(NSInteger)index
{
    NSRange range = NSMakeRange(index, 0);
    UITextPosition *start = [textField positionFromPosition:[textField beginningOfDocument] offset:range.location];
    UITextPosition *end = [textField positionFromPosition:start offset:range.length];
    [textField setSelectedTextRange:[textField textRangeFromPosition:start toPosition:end]];
}

56、去除webView底部黑色

    [webView setBackgroundColor:[UIColor clearColor]];
    [webView setOpaque:NO];

    for (UIView *v1 in [webView subviews])
    {
        if ([v1 isKindOfClass:[UIScrollView class]])
        {
            for (UIView *v2 in v1.subviews)
            {
                if ([v2 isKindOfClass:[UIImageView class]])
                {
                    v2.hidden = YES;
                }
            }
        }
    }

57、获取collectionViewCell在屏幕中的frame

UICollectionViewLayoutAttributes *attributes = [collectionView layoutAttributesForItemAtIndexPath:indexPath];
CGRect cellRect = attributes.frame;
CGRect cellFrameInSuperview = [collectionView convertRect:cellRect toView:[cv superview]];

58、比较两个UIImage是否相等

- (BOOL)image:(UIImage *)image1 isEqualTo:(UIImage *)image2
{
    NSData *data1 = UIImagePNGRepresentation(image1);
    NSData *data2 = UIImagePNGRepresentation(image2);

    return [data1 isEqual:data2];
}

59、解决当UIScrollView上有UIButton的时候,触摸到button滑动不了的问题

// 子类化UIScrollView,并重写以下方法
- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        self.delaysContentTouches = NO;
    }

    return self;
}

- (BOOL)touchesShouldCancelInContentView:(UIView *)view {
    if ([view isKindOfClass:UIButton.class]) {
        return YES;
    }

    return [super touchesShouldCancelInContentView:view];
}

60、UITextView中的文字添加阴影效果

- (void)setTextLayer:(UITextView *)textView color:(UIColor *)color
{
    CALayer *textLayer = ((CALayer *)[textView.layer.sublayers objectAtIndex:0]);
    textLayer.shadowColor = color.CGColor;
    textLayer.shadowOffset = CGSizeMake(0.0f, 1.0f);
    textLayer.shadowOpacity = 1.0f;
    textLayer.shadowRadius = 1.0f;
}

61、MD5加密

+ (NSString *)md5:(NSString *)str
{
    const char *concat_str = [str UTF8String];
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(concat_str, (unsigned int)strlen(concat_str), result);
    NSMutableString *hash = [NSMutableString string];
    for (int i =0; i <16; i++){
        [hash appendFormat:@"%02X", result[i]];
    }
    return [hash uppercaseString];
}

62、base64加密

@interface NSData (Base64)
/**
 *  @brief  字符串base64后转data
 */
+ (NSData *)dataWithBase64EncodedString:(NSString *)string
{
    if (![string length]) return nil;
    NSData *decoded = nil;
#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0
    if (![NSData instancesRespondToSelector:@selector(initWithBase64EncodedString:options:)])
    {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
        decoded = [[self alloc] initWithBase64Encoding:[string stringByReplacingOccurrencesOfString:@"[^A-Za-z0-9+/=]" withString:@"" options:NSRegularExpressionSearch range:NSMakeRange(0, [string length])]];
#pragma clang diagnostic pop
    }
    else
#endif
    {
        decoded = [[self alloc] initWithBase64EncodedString:string options:NSDataBase64DecodingIgnoreUnknownCharacters];
    }
    return [decoded length]? decoded: nil;
}
/**
 *  @brief  NSData转string
 *  @param wrapWidth 换行长度  76  64
 */
- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth
{
    if (![self length]) return nil;
    NSString *encoded = nil;
#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0
    if (![NSData instancesRespondToSelector:@selector(base64EncodedStringWithOptions:)])
    {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
        encoded = [self base64Encoding];
#pragma clang diagnostic pop

    }
    else
#endif
    {
        switch (wrapWidth)
        {
            case 64:
            {
                return [self base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
            }
            case 76:
            {
                return [self base64EncodedStringWithOptions:NSDataBase64Encoding76CharacterLineLength];
            }
            default:
            {
                encoded = [self base64EncodedStringWithOptions:(NSDataBase64EncodingOptions)0];
            }
        }
    }
    if (!wrapWidth || wrapWidth >= [encoded length])
    {
        return encoded;
    }
    wrapWidth = (wrapWidth / 4) * 4;
    NSMutableString *result = [NSMutableString string];
    for (NSUInteger i = 0; i < [encoded length]; i+= wrapWidth)
    {
        if (i + wrapWidth >= [encoded length])
        {
            [result appendString:[encoded substringFromIndex:i]];
            break;
        }
        [result appendString:[encoded substringWithRange:NSMakeRange(i, wrapWidth)]];
        [result appendString:@"\r\n"];
    }
    return result;
}
/**
 *  @brief  NSData转string 换行长度默认64
 */
- (NSString *)base64EncodedString
{
    return [self base64EncodedStringWithWrapWidth:0];
}

63、AES加密

#import <CommonCrypto/CommonCryptor.h>
@interface NSData (AES)
/**
 *  利用AES加密数据
 */
- (NSData*)encryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128];

    CCCryptorStatus status = CCCrypt(kCCEncrypt,kCCAlgorithmAES128,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,encryptedData.mutableBytes, encryptedData.length,&dataMoved);

    if (status == kCCSuccess) {
        encryptedData.length = dataMoved;
        return encryptedData;
    }

    return nil;

}

/**
 *  @brief  利用AES解密据
 */
- (NSData*)decryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128];

    CCCryptorStatus result = CCCrypt(kCCDecrypt,kCCAlgorithmAES128,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,decryptedData.mutableBytes, decryptedData.length,&dataMoved);

    if (result == kCCSuccess) {
        decryptedData.length = dataMoved;
        return decryptedData;
    }

    return nil;

}

64、3DES加密

#import <CommonCrypto/CommonCryptor.h>
@interface NSData (3DES)
/**
 *  利用3DES加密数据
 */
- (NSData*)encryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES];

    CCCryptorStatus result = CCCrypt(kCCEncrypt,kCCAlgorithm3DES,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,encryptedData.mutableBytes,encryptedData.length,&dataMoved);

    if (result == kCCSuccess) {
        encryptedData.length = dataMoved;
        return encryptedData;
    }

    return nil;

}
/**
 *  @brief   利用3DES解密数据
 */
- (NSData*)decryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES];

    CCCryptorStatus result = CCCrypt(kCCDecrypt,kCCAlgorithm3DES,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,decryptedData.mutableBytes,decryptedData.length,&dataMoved);

    if (result == kCCSuccess) {
        decryptedData.length = dataMoved;
        return decryptedData;
    }

    return nil;

}

65、单个页面多个网络请求的情况,需要监听所有网络请求结束后刷新UI

dispatch_group_t group = dispatch_group_create();
    dispatch_queue_t serialQueue = dispatch_queue_create("com.wzb.test.www", DISPATCH_QUEUE_SERIAL);
    dispatch_group_enter(group);
    dispatch_group_async(group, serialQueue, ^{
        // 网络请求一
        [WebClick getDataSuccess:^(ResponseModel *model) {
            dispatch_group_leave(group);
        } failure:^(NSString *err) {
            dispatch_group_leave(group);
        }];
    });
    dispatch_group_enter(group);
    dispatch_group_async(group, serialQueue, ^{
        // 网络请求二
        [WebClick getDataSuccess:getBigTypeRM onSuccess:^(ResponseModel *model) {
            dispatch_group_leave(group);
        }                                  failure:^(NSString *errorString) {
            dispatch_group_leave(group);
        }];
    });
    dispatch_group_enter(group);
    dispatch_group_async(group, serialQueue, ^{
        // 网络请求三
        [WebClick getDataSuccess:^{
            dispatch_group_leave(group);
        } failure:^(NSString *errorString) {
            dispatch_group_leave(group);
        }];
    });

    // 所有网络请求结束后会来到这个方法
    dispatch_group_notify(group, serialQueue, ^{
        dispatch_async(dispatch_get_global_queue(0, 0), ^{
            dispatch_async(dispatch_get_main_queue(), ^{
                // 刷新UI
            });
        });
    });

66、解决openUrl延时问题

// 方法一
dispatch_async(dispatch_get_main_queue(), ^{

    UIApplication *application = [UIApplication sharedApplication];
    if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {
        [application openURL:URL options:@{}
           completionHandler:nil];
    } else {
        [application openURL:URL];
    }
    });
// 方法二
[self performSelector:@selector(redirectToURL:) withObject:url afterDelay:0.1];

- (void) redirectToURL
{
UIApplication *application = [UIApplication sharedApplication];
    if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {
        [application openURL:URL options:@{}
           completionHandler:nil];
    } else {
        [application openURL:URL];
    }
}

67、页面跳转实现翻转动画

// modal方式
    TestViewController *vc = [[TestViewController alloc] init];
    vc.view.backgroundColor = [UIColor redColor];
    vc.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
    [self presentViewController:vc animated:YES completion:nil];

// push方式
    TestViewController *vc = [[TestViewController alloc] init];
    vc.view.backgroundColor = [UIColor redColor];
    [UIView beginAnimations:@"View Flip" context:nil];
    [UIView setAnimationDuration:0.80];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.navigationController.view cache:NO];
    [self.navigationController pushViewController:vc animated:YES];
    [UIView commitAnimations];

68、tableView实现无限滚动

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat actualPosition = scrollView.contentOffset.y;
    CGFloat contentHeight = scrollView.contentSize.height - scrollView.frame.size.height;
    if (actualPosition >= contentHeight) {
        [self.dataArr addObjectsFromArray:self.dataArr];
        [self.tableView reloadData];
    }
}

69、代码方式调整屏幕亮度

// brightness属性值在0-1之间,0代表最小亮度,1代表最大亮度
[[UIScreen mainScreen] setBrightness:0.5];

70、获取当前应用CUP用量

float cpu_usage()
{
    kern_return_t kr;
    task_info_data_t tinfo;
    mach_msg_type_number_t task_info_count;

    task_info_count = TASK_INFO_MAX;
    kr = task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)tinfo, &task_info_count);
    if (kr != KERN_SUCCESS) {
        return -1;
    }

    task_basic_info_t      basic_info;
    thread_array_t         thread_list;
    mach_msg_type_number_t thread_count;

    thread_info_data_t     thinfo;
    mach_msg_type_number_t thread_info_count;

    thread_basic_info_t basic_info_th;
    uint32_t stat_thread = 0; // Mach threads

    basic_info = (task_basic_info_t)tinfo;

    // get threads in the task
    kr = task_threads(mach_task_self(), &thread_list, &thread_count);
    if (kr != KERN_SUCCESS) {
        return -1;
    }
    if (thread_count > 0)
        stat_thread += thread_count;

    long tot_sec = 0;
    long tot_usec = 0;
    float tot_cpu = 0;
    int j;

    for (j = 0; j < (int)thread_count; j++)
    {
        thread_info_count = THREAD_INFO_MAX;
        kr = thread_info(thread_list[j], THREAD_BASIC_INFO,
                         (thread_info_t)thinfo, &thread_info_count);
        if (kr != KERN_SUCCESS) {
            return -1;
        }

        basic_info_th = (thread_basic_info_t)thinfo;

        if (!(basic_info_th->flags & TH_FLAGS_IDLE)) {
            tot_sec = tot_sec + basic_info_th->user_time.seconds + basic_info_th->system_time.seconds;
            tot_usec = tot_usec + basic_info_th->user_time.microseconds + basic_info_th->system_time.microseconds;
            tot_cpu = tot_cpu + basic_info_th->cpu_usage / (float)TH_USAGE_SCALE * 100.0;
        }

    } // for each thread

    kr = vm_deallocate(mach_task_self(), (vm_offset_t)thread_list, thread_count * sizeof(thread_t));
    assert(kr == KERN_SUCCESS);

    return tot_cpu;
}

71、float数据取整四舍五入

    CGFloat f = 4.65;
    NSLog(@"%d", (int)f);    // 打印结果4

    CGFloat f = 4.65;
    NSLog(@"%d", (int)round(f));    // 打印结果5

72、删除UISearchBar系统默认边框

    // 方法一
    searchBar.searchBarStyle = UISearchBarStyleMinimal;

    // 方法二
    [searchBar setBackgroundImage:[[UIImage alloc]init]];

    // 方法三
    searchBar.barTintColor = [UIColor whiteColor];

73、为UICollectionViewCell设置圆角和阴影

cell.contentView.layer.cornerRadius = 2.0f;
cell.contentView.layer.borderWidth = 1.0f;
cell.contentView.layer.borderColor = [UIColor clearColor].CGColor;
cell.contentView.layer.masksToBounds = YES;

cell.layer.shadowColor = [UIColor lightGrayColor].CGColor;
cell.layer.shadowOffset = CGSizeMake(0, 2.0f);
cell.layer.shadowRadius = 2.0f;
cell.layer.shadowOpacity = 1.0f;
cell.layer.masksToBounds = NO;
cell.layer.shadowPath = [UIBezierPath bezierPathWithRoundedRect:cell.bounds cornerRadius:cell.contentView.layer.cornerRadius].CGPath;

74、让正在滑动的scrollView停止滚动(不是禁止,而是暂时停止滚动)

[scrollView setContentOffset:scrollView.contentOffset animated:NO];

75、使用xib设置UIView的边框、圆角

圆角和边框看下图即可设置

xib设置圆角边框.png

但是增加layer.borderColor的keyPath设置边框颜色并不能起作用,后来查了资料,这里应该用layer.borderUIColor,但是这里设置的颜色不起作用,无论设置什么颜色显示出来的都是黑色的。后来又去查了下,有种解决方案是给CALayer添加一个分类,提供一个 - (void)setBorderUIColor:(UIColor *)color;方法就可以解决了,实现如下:

xib设置边框颜色.png

#import "CALayer+BorderColor.h"

@implementation CALayer (BorderColor)

- (void)setBorderUIColor:(UIColor *)color
{
    self.borderColor = color.CGColor;
}

76、根据经纬度获取城市等信息

// 创建经纬度
    CLLocation *location = [[CLLocation alloc] initWithLatitude:latitude longitude:longitude];
    //创建一个译码器
    CLGeocoder *cLGeocoder = [[CLGeocoder alloc] init];
    [cLGeocoder reverseGeocodeLocation:userLocation completionHandler:^(NSArray *placemarks, NSError *error) {
        CLPlacemark *place = [placemarks objectAtIndex:0];
        // 位置名
      NSLog(@"name,%@",place.name);
      // 街道
      NSLog(@"thoroughfare,%@",place.thoroughfare);
      // 子街道
      NSLog(@"subThoroughfare,%@",place.subThoroughfare);
      // 市
      NSLog(@"locality,%@",place.locality);
      // 区
      NSLog(@"subLocality,%@",place.subLocality); 
      // 国家
      NSLog(@"country,%@",place.country);
        }
    }];

/*  CLPlacemark中属性含义
name                    地名

thoroughfare            街道

subThoroughfare        街道相关信息,例如门牌等

locality                城市

subLocality            城市相关信息,例如标志性建筑

administrativeArea      直辖市

subAdministrativeArea  其他行政区域信息(自治区等)

postalCode              邮编

ISOcountryCode          国家编码

country                国家

inlandWater            水源,湖泊

ocean                  海洋

areasOfInterest        关联的或利益相关的地标
*/

77、如何防止添加多个NSNotification观察者?

// 解决方案就是添加观察者之前先移除下这个观察者
[[NSNotificationCenter defaultCenter] removeObserver:observer name:name object:object];
        [[NSNotificationCenter defaultCenter] addObserver:observer selector:selector name:name object:object];

78、将一个xib添加到另外一个xib上

// 假设你的自定义view名字为CustomView,你需要在CustomView.m中重写 `- (instancetype)initWithCoder:(NSCoder *)aDecoder` 方法,代码如下:
- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    if ((self = [super initWithCoder:aDecoder])) {
        [self addSubview:[[[NSBundle mainBundle] loadNibNamed:@"CustomView" owner:self options:nil] objectAtIndex:0]];
    }
    return self;
}

将一个xib添加到另外一个xib上.png

79、处理字符串,使其首字母大写

    NSString *str = @"abcdefghijklmn";
    NSString *resultStr;
    if (str && str.length > 0) {
        resultStr = [str stringByReplacingCharactersInRange:NSMakeRange(0,1) withString:[[str substringToIndex:1] capitalizedString]];
    }
    NSLog(@"%@", resultStr);

80、判断一个UIAlertView/UIAlertController是否显示

// UIAlertView自带属性
if (alert.visible)
{
      NSLog(@"显示了");
} else {
      NSLog(@"未显示");
}

// UIAlertController没有visible属性,需要自己判断,添加一个全局变量 BOOL visible
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];
    UIAlertAction *alertAction = [UIAlertAction actionWithTitle:@"ActionTitle" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        self.visible = NO;
    }];
    UIAlertAction *calcelAction = [UIAlertAction actionWithTitle:@"calcelTitle" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
        self.visible = NO;
    }];
    [alertController addAction:alertAction];
    [alertController addAction:calcelAction];
    [self presentViewController:alertController animated:YES completion:^{
        self.visible = YES;
    }];

81、获取字符串中的数字

- (NSString *)getNumberFromStr:(NSString *)str
{
    NSCharacterSet *nonDigitCharacterSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
    return [[str componentsSeparatedByCharactersInSet:nonDigitCharacterSet] componentsJoinedByString:@""];
}

    NSLog(@"%@", [self getNumberFromStr:@"a0b0c1d2e3f4fda8fa8fad9fsad23"]); // 00123488923

82、为UIView的某个方向添加边框

// 添加UIView分类

// UIView+WZB.h
#import <UIKit/UIKit.h>


/**
 边框方向

 - WZBBorderDirectionTop: 顶部
 - WZBBorderDirectionLeft: 左边
 - WZBBorderDirectionBottom: 底部
 - WZBBorderDirectionRight: 右边
 */
typedef NS_ENUM(NSInteger, WZBBorderDirectionType) {
    WZBBorderDirectionTop = 0,
    WZBBorderDirectionLeft,
    WZBBorderDirectionBottom,
    WZBBorderDirectionRight
};

@interface UIView (WZB)


/**
 为UIView的某个方向添加边框

 @param direction 边框方向
 @param color 边框颜色
 @param width 边框宽度
 */
- (void)wzb_addBorder:(WZBBorderDirectionType)direction color:(UIColor *)color width:(CGFloat)width;

@end

// UIView+WZB.m
#import "UIView+WZB.h"

@implementation UIView (WZB)

- (void)wzb_addBorder:(WZBBorderDirectionType)direction color:(UIColor *)color width:(CGFloat)width
{
    CALayer *border = [CALayer layer];
    border.backgroundColor = color.CGColor;
    switch (direction) {
        case WZBBorderDirectionTop:
        {
            border.frame = CGRectMake(0.0f, 0.0f, self.bounds.size.width, width);
        }
            break;
        case WZBBorderDirectionLeft:
        {
            border.frame = CGRectMake(0.0f, 0.0f, width, self.bounds.size.height);
        }
            break;
        case WZBBorderDirectionBottom:
        {
            border.frame = CGRectMake(0.0f, self.bounds.size.height - width, self.bounds.size.width, width);
        }
            break;
        case WZBBorderDirectionRight:
        {
            border.frame = CGRectMake(self.bounds.size.width - width, 0, width, self.bounds.size.height);
        }
            break;

        default:
            break;
    }
    [self.layer addSublayer:border];
}

83、通过属性设置UISwitch、UIProgressView等控件的宽高

mySwitch.transform = CGAffineTransformMakeScale(5.0f, 5.0f);

progressView.transform = CGAffineTransformMakeScale(5.0f, 5.0f);

84、自动搜索功能,用户连续输入的时候不搜索,用户停止输入的时候自动搜索(我这里设置的是0.5s,可根据需求更改)

// 输入框文字改变的时候调用
-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText{
    // 先取消调用搜索方法
    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(searchNewResult) object:nil];
    // 0.5秒后调用搜索方法
    [self performSelector:@selector(searchNewResult) withObject:nil afterDelay:0.5];
}

85、修改UISearchBar的占位文字颜色

    // 方法一(推荐使用)
    UITextField *searchField = [searchBar valueForKey:@"_searchField"];
    [searchField setValue:[UIColor blueColor] forKeyPath:@"_placeholderLabel.textColor"];

    // 方法二(已过期)
    [[UILabel appearanceWhenContainedIn:[UISearchBar class], nil] setTextColor:[UIColor redColor]];

    // 方法三(已过期)
    NSDictionary *placeholderAttributes = @{NSForegroundColorAttributeName : [UIColor redColor], NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue" size:15],};
    NSAttributedString *attributedPlaceholder = [[NSAttributedString alloc] initWithString:searchBar.placeholder attributes:placeholderAttributes];
    [[UITextField appearanceWhenContainedIn:[UISearchBar class], nil] setAttributedPlaceholder:attributedPlaceholder];

86、某个界面多个事件同时响应引起的问题(比如,两个button同时按push到新界面,两个都会响应,可能导致push重叠)

// UIView有个属性叫做exclusiveTouch,设置为YES后,其响应事件会和其他view互斥(有其他view事件响应的时候点击它不起作用)
view.exclusiveTouch = YES;

// 一个一个设置太麻烦了,可以全局设置
[[UIView appearance] setExclusiveTouch:YES];

// 或者只设置button
[[UIButton appearance] setExclusiveTouch:YES];

87、修改tabBar的frame

// 子类化UITabBarViewController,我这里以修改tabBar高度为例,重写viewWillLayoutSubviews方法
#import "WZBTabBarViewController.h"

@interface WZBTabBarViewController ()

@end

@implementation WZBTabBarViewController
- (void)viewWillLayoutSubviews {

    CGRect tabFrame = self.tabBar.frame;
    tabFrame.size.height = 100;
    tabFrame.origin.y = self.view.frame.size.height - 100;
    self.tabBar.frame = tabFrame;
}
@end

88、修改键盘背景颜色

// 设置某个键盘颜色
    textField.keyboardAppearance = UIKeyboardAppearanceAlert;

// 设置工程中所有键盘颜色
[[UITextField appearance] setKeyboardAppearance:UIKeyboardAppearanceAlert];

89、修改image颜色

UIImage *image = [UIImage imageNamed:@"test"];
    imageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
    CGRect rect = CGRectMake(0, 0, image.size.width, image.size.height);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextClipToMask(context, rect, image.CGImage);
    CGContextSetFillColorWithColor(context, [[UIColor redColor] CGColor]);
    CGContextFillRect(context, rect);
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    UIImage *flippedImage = [UIImage imageWithCGImage:img.CGImage scale:1.0 orientation: UIImageOrientationDownMirrored];
    imageView.image = flippedImage;

90、动画执行removeFromSuperview

    [UIView animateWithDuration:0.2
                     animations:^{
                         view.alpha = 0.0f;
                     } completion:^(BOOL finished){
                         [view removeFromSuperview];
                     }];

91、设置UIButton高亮背景颜色

    [UIView animateWithDuration:0.2
                     animations:^{
                         view.alpha = 0.0f;
                     } completion:^(BOOL finished){
                         [view removeFromSuperview];
                     }];

92、设置UIButton高亮时的背景颜色

// 方法一、子类化UIButton,重写setHighlighted:方法,代码如下
#import "WZBButton.h"

@implementation WZBButton

- (void)setHighlighted:(BOOL)highlighted {
    [super setHighlighted:highlighted];

    UIColor *normalColor = [UIColor greenColor];
    UIColor *highlightedColor = [UIColor redColor];
    self.backgroundColor = highlighted ? highlightedColor : normalColor;

}

// 方法二、利用setBackgroundImage:forState:方法
[button setBackgroundImage:[self imageWithColor:[UIColor blueColor]] forState:UIControlStateHighlighted];

- (UIImage *)imageWithColor:(UIColor *)color {
    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return image;
}

93、关于图片拉伸

推荐看这个博客,讲的很详细http://blog.csdn.net/q199109106q/article/details/8615661

94、利用runtime获取一个类所有属性

- (NSArray *)allPropertyNames:(Class)aClass
{
    unsigned count;
    objc_property_t *properties = class_copyPropertyList(aClass, &count);

    NSMutableArray *rv = [NSMutableArray array];

    unsigned i;
    for (i = 0; i < count; i++)
    {
        objc_property_t property = properties[i];
        NSString *name = [NSString stringWithUTF8String:property_getName(property)];
        [rv addObject:name];
    }

    free(properties);

    return rv;
}

95、设置textView的某段文字变成其他颜色

- (void)setupTextView:(UITextView *)textView text:(NSString *)text color:(UIColor *)color {
    NSMutableAttributedString *string = [[NSMutableAttributedString alloc]initWithString:textView.text];
    [string addAttribute:NSForegroundColorAttributeName value:color range:[textView.text rangeOfString:text]];
    [textView setAttributedText:string];
}

96、让push跳转动画像modal跳转动画那样效果(从下往上推上来)

- (void)push
{
TestViewController *vc = [[TestViewController alloc] init];
    vc.view.backgroundColor = [UIColor redColor];
    CATransition* transition = [CATransition animation];
    transition.duration = 0.4f;
    transition.type = kCATransitionMoveIn;
    transition.subtype = kCATransitionFromTop;
    [self.navigationController.view.layer addAnimation:transition forKey:kCATransition];
    [self.navigationController pushViewController:vc animated:NO];
}

- (void)pop
{
CATransition* transition = [CATransition animation];
    transition.duration = 0.4f;
    transition.type = kCATransitionReveal;
    transition.subtype = kCATransitionFromBottom;
    [self.navigationController.view.layer addAnimation:transition forKey:kCATransition];
    [self.navigationController popViewControllerAnimated:NO];
}

97、上传图片太大,压缩图片

-(UIImage *)resizeImage:(UIImage *)image
{
    float actualHeight = image.size.height;
    float actualWidth = image.size.width;
    float maxHeight = 300.0;
    float maxWidth = 400.0;
    float imgRatio = actualWidth/actualHeight;
    float maxRatio = maxWidth/maxHeight;
    float compressionQuality = 0.5;//50 percent compression

    if (actualHeight > maxHeight || actualWidth > maxWidth)
    {
        if(imgRatio < maxRatio)
        {
            //adjust width according to maxHeight
            imgRatio = maxHeight / actualHeight;
            actualWidth = imgRatio * actualWidth;
            actualHeight = maxHeight;
        }
        else if(imgRatio > maxRatio)
        {
            //adjust height according to maxWidth
            imgRatio = maxWidth / actualWidth;
            actualHeight = imgRatio * actualHeight;
            actualWidth = maxWidth;
        }
        else
        {
            actualHeight = maxHeight;
            actualWidth = maxWidth;
        }
    }

    CGRect rect = CGRectMake(0.0, 0.0, actualWidth, actualHeight);
    UIGraphicsBeginImageContext(rect.size);
    [image drawInRect:rect];
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    NSData *imageData = UIImageJPEGRepresentation(img, compressionQuality);
    UIGraphicsEndImageContext();

    return [UIImage imageWithData:imageData];

}

由于简书对文章篇幅有一定限制,只能分篇书写,感兴趣的朋友不妨关注一下,后面还有很多高质量的东西准备分享!文章中的代码有问题可以直接私信我或者加入我们的技术群一起交流。

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