摘要: 主要通过代码的方式取了解Activity生命活动的周期。。。。。
package com.example.mrzou.project002_activity; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.util.Log; import android.view.View; import android.view.Menu; import android.view.MenuItem; import android.widget.Button; public class MainActivity extends Activity { final String TAG ="tag"; private Button bt; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 添加一个输出日志:Log.i("标签";"输出内容") Log.i(TAG, "MainActvity -->OnCreate"); bt=(Button)findViewById(R.id.button); bt.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //点击按钮,启动第二个Activity Intent intent =new Intent(MainActivity.this,Second_Activity.class); MainActivity.this.startActivity(intent); } }); } @Override protected void onStart() { super.onStart(); Log.i(TAG, "MainActvity -->onStart"); } @Override protected void onResume() { super.onResume(); Log.i(TAG, "MainActvity -->onResume"); } @Override protected void onPause() { super.onPause(); Log.i(TAG, "MainActvity -->onPause"); } @Override protected void onStop() { super.onStop(); Log.i(TAG, "MainActvity -->onStop"); } @Override protected void onDestroy() { super.onDestroy(); Log.i(TAG, "MainActvity -->onDestroy"); } @Override protected void onRestart() { super.onRestart(); Log.i(TAG, "MainActvity -->onRestart"); } }
AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.mrzou.project002_activity">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".Second_Activity"
android:theme="@android:style/Theme.DeviceDefault.Dialog"/>
</application>
</manifest>
(1)从启动到后台,再到前台的生命周期: onCreate() —> onStart() —> onResume() —> onPause —> onStop() —> onRestart() —> onStart() —> onResume()
这份代码主要是通过点击第一份代码的Button,跳转到第二个Activity了解其生命周期(从启动到失去焦点,再到获取到焦点的生命周期)。主要是:onCreate() —>onStart() —>onResume() —>onPause() —>onResume()
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