上面的程序仅仅可以显示一个 大概 的界面，对其进行单击等操作，界面仅有一些简单的反应，对应的程序不能得知界面有什么改变（是否进行单击选择，文本框中是否有文字输入）
下面对程序进行完善。
T05Controls.pro
1 HEADERS += \
2 MyWidget.h
3
4 SOURCES += \
5 MyWidget.cpp
6
7 QT += widgets gui
8
9 CONFIG += C++11
MyWidget.h
1 #ifndef MYWIDGET_H
2 #define MYWIDGET_H
3
4 #include <QWidget>
5 #include <QTextEdit>
6 class MyWidget : public QWidget
7 {
8 Q_OBJECT
9 public:
10 explicit MyWidget(QWidget *parent = nullptr);
11
12 QTextEdit* _edit; //保存到成员变量里面
13
14 signals:
15
16 public slots:
17 void slotComboBoxIndexChanged(const QString&); //槽 函数
18 };
19
20 #endif // MYWIDGET_H
MyWidget.cpp
1 #include "MyWidget.h"
2 #include <QApplication>
3 #include <QLabel> //display ststic text, or image
4 #include <QPushButton>
5 #include <QLineEdit> //single line
6
7 #include <QComboBox>
8 #include <QCheckBox>
9 #include <QRadioButton>
10 #include <QTextEdit> //multi lines, rich text
11 #include <QTextBrowser> //readonly textedit
12 #include <QGroupBox>
13 #include <QSlider> //模拟方式显示数值
14 #include <QSpinBox> //数字
15 #include <QDateEdit>
16 #include <QTimeEdit>
17 #include <QDateTimeEdit>
18 #include <QTabWidget> //不介绍，不算控件
19
20 #include <QCompleter>
21 #include <QVBoxLayout>
22 #include <QDebug>
23 #include <QHBoxLayout>
24 #include <QLCDNumber>
25 MyWidget::MyWidget(QWidget *parent) : QWidget(parent)
26 {
27 QVBoxLayout* lay = new QVBoxLayout(this); //this ,MyWidget,不用写this->setLayout();
28 QLabel* label;
29 QComboBox* combo;
30 QPushButton* button;
31 QRadioButton* radio;
32 QTextEdit* edit;
33 QGroupBox* group;
34
35 lay->addWidget(label = new QLabel("<font color = red>Label</font>")); //支持html,静态文本
36
37
38 lay->addWidget(button = new QPushButton("Button"));
39 button->setStyleSheet("QPushButton {font:bold 16px; color:green}");
40
41 lay->addWidget(radio = new QRadioButton("Radio"));
42 radio->setStyleSheet("QRadioButton {font:bold 16px; color:blue}");
43 connect(radio, &QRadioButton::clicked,[](bool v){
44 qDebug() << v;
45 });
46
47
48 lay->addWidget(new QCheckBox("check box"));
49
50
51 lay->addWidget(combo = new QComboBox());
52 combo->addItem("Select item1");
53 combo->addItem("Select item2");
54 combo->addItem("nizhipeng");
55 combo->addItem("jackson");
56 combo->setEditable(true); //下拉框可编辑
57 connect(combo, SIGNAL(currentIndexChanged(QString)), this, SLOT(slotComboBoxIndexChanged(QString)));
58
59 combo->setCompleter(new QCompleter(QStringList() << "nizhipeng" << "jackson" ));
60
61
62 lay->addWidget(edit = new QTextEdit);
63 edit->setText("<table border=1><tr><th>head1</th><th>head2</th></tr>"
64 "<tr><td>value1</td><td>value2</td></tr>"
65 "<tr><td>value3</td><td>value4</td></tr>"
66 "</table><br>"
67 "<img src=../doge.jpg></img>");
68 _edit = edit;
69 connect(edit, &QTextEdit::textChanged, [&](){
70 //(QTextEdit*) edit = this->sender();
71 qDebug() << _edit->toPlainText();
72 });
73 //edit->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded); 不写也有滚动条
74 //edit->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);//将水平滚动条取消
75
76 lay->addWidget(group = new QGroupBox("Some items"));//lay->addWidget(group = new QGroupBox);
77 QHBoxLayout* hBoxlay;
78 group->setLayout(hBoxlay = new QHBoxLayout);
79 hBoxlay->addWidget(new QPushButton("aaa"));
80 hBoxlay->addWidget(new QPushButton("aaa"));
81
82 QSlider* slider;
83 QSpinBox* spinBox;
84
85 lay->addWidget(slider = new QSlider(Qt::Horizontal));
86 slider->setMaximum(100);
87 slider->setMinimum(0);
88 //slider->value();
89
90 lay->addWidget(spinBox = new QSpinBox);
91 spinBox->setMaximum(100);
92 spinBox->setMinimum(0);
93
94 connect(slider,SIGNAL(valueChanged(int)), spinBox, SLOT(setValue(int)));//互相影响
95 connect(spinBox,SIGNAL(valueChanged(int)), slider, SLOT(setValue(int)));
96
97
98 lay->addWidget(new QDateTimeEdit);
99
100 QLCDNumber* lcd;
101 lay->addWidget(lcd = new QLCDNumber(10));
102 lcd->display(112358);
103 //lcd->setMode(QLCDNumber::Hex); //16进制
104 lcd->setSegmentStyle(QLCDNumber::Flat);//数字更清晰
105
106 }
107
108 //槽函数
109 void MyWidget::slotComboBoxIndexChanged(const QString &str)
110 {
111 qDebug() << "slotComboBoxIndexChanged" << str;
112 }
113
114 int main(int argc, char** argv)
115 {
116 QApplication app(argc, argv);
117
118 MyWidget w;
119 w.show();
120
121 return app.exec();
122 } 
下面详细的介绍以上完整的程序：
1 QLabel* label;
2 lay->addWidget(label = new QLabel("<font color = red>Label</font>")); //支持html,静态文本
1 QPushButton* button;
2 lay->addWidget(button = new QPushButton("Button"));
3 button->setStyleSheet("QPushButton {font:bold 16px; color:green}");如果不需要特殊设置颜色，只需要写成 lay->addWidget( new QPushButton("Button") );
1 QRadioButton* radio;
2 lay->addWidget(radio = new QRadioButton("Radio"));
3 radio->setStyleSheet("QRadioButton {font:bold 16px; color:blue}");//设置颜色
4 connect(radio, &QRadioButton::clicked,[](bool v){
5 qDebug() << v;
6 });选择返回true,不选择返回false。
lay->addWidget(new QCheckBox("check box"));仅仅显示
1 QComboBox* combo;
2 lay->addWidget(combo = new QComboBox());
3 combo->addItem("Select item1");
4 combo->addItem("Select item2");
5 combo->addItem("nizhipeng");
6 combo->addItem("jackson");
7 combo->setEditable(true); //下拉框可编辑
8 connect(combo, SIGNAL(currentIndexChanged(QString)), this,SLOT(slotComboBoxIndexChanged(QString)));
9
10 combo->setCompleter(new QCompleter(QStringList() << "nizhipeng" << "jackson" ));//补全提示设置下拉框中内容，获得改变后的值，设置补全提示。
其中槽函数为：
1 //槽函数
2 void MyWidget::slotComboBoxIndexChanged(const QString &str)
3 {
4 qDebug() << "slotComboBoxIndexChanged" << str;
5 }输出为 "slotComboBoxIndexChanged" << str;与上图一致。根据下拉框中选择的内容，返回对应的内容。
1 QTextEdit* edit;
2 lay->addWidget(edit = new QTextEdit);
3 edit->setText("<table border=1><tr><th>head1</th><th>head2</th></tr>"
4 "<tr><td>value1</td><td>value2</td></tr>"
5 "<tr><td>value3</td><td>value4</td></tr>"
6 "</table><br>"
7 "<img src=../doge.jpg></img>");
8 _edit = edit;
9 connect(edit, &QTextEdit::textChanged, [&](){
10 //(QTextEdit*) edit = this->sender();
11 qDebug() << _edit->toPlainText();
12 });可以输入的文本框。
1 QGroupBox* group;
2 lay->addWidget(group = new QGroupBox("Some items"));//lay->addWidget(group = new QGroupBox);
3 QHBoxLayout* hBoxlay;
4 group->setLayout(hBoxlay = new QHBoxLayout);
5 hBoxlay->addWidget(new QPushButton("aaa"));
6 hBoxlay->addWidget(new QPushButton("aaa"));
1 QSlider* slider;
2 QSpinBox* spinBox;
3
4 lay->addWidget(slider = new QSlider(Qt::Horizontal));
5 slider->setMaximum(100);
6 slider->setMinimum(0);
7 //slider->value();
8
9 lay->addWidget(spinBox = new QSpinBox);
10 spinBox->setMaximum(100);
11 spinBox->setMinimum(0);
12
13 connect(slider,SIGNAL(valueChanged(int)), spinBox, SLOT(setValue(int)));//互相影响
14 connect(spinBox,SIGNAL(valueChanged(int)), slider, SLOT(setValue(int)));上下的值互相对应，一个改变另一个也改变。
lay->addWidget(new QDateTimeEdit);
1 QLCDNumber* lcd;
2 lay->addWidget(lcd = new QLCDNumber(10));
3 lcd->display(112358);
4 //lcd->setMode(QLCDNumber::Hex); //16进制
5 lcd->setSegmentStyle(QLCDNumber::Flat);//数字更清晰
