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在学习Android应用生命周期章节中,书本上写的有点笼统,较难理解。为了理解的更深,写了个程序测试一下。
1、在layout文件夹中建一个dialog_layout.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="This is a dialog Activity." /> </LinearLayout>
2、在layout文件夹中再建一个normal_layout.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="This is a normal Activity." /> </LinearLayout>
3、修改layout文件夹中的activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" > <Button android:id="@+id/start_normal_activity" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Start NormalActivity" /> <Button android:id="@+id/start_dialog_activity" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Start DialogActivity" /> </LinearLayout>
4、编写java文件,建立一个DialogActivity.java
package com.example.acitivitylife; import android.app.Activity; import android.os.Bundle; public class DialogActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.dialog_layout); } }
5、编写java文件,建立一个NormalActivity.java
package com.example.acitivitylife; import android.app.Activity; import android.os.Bundle; public class NormalActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.normal_layout); } }
6、修改MainActivity.java
package com.example.acitivitylife; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class MainActivity extends Activity { public static final String TAG = "MainActivity"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Log.d(TAG, "onCreate"); setContentView(R.layout.activity_main); Button startNormalActivity = (Button)findViewById(R.id.start_normal_activity); Button startDialogActivity = (Button)findViewById(R.id.start_dialog_activity); startNormalActivity.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub Intent intent = new Intent(MainActivity.this, NormalActivity.class); startActivity(intent); } }); startDialogActivity.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub Intent intent = new Intent(MainActivity.this, DialogActivity.class); startActivity(intent); } }); } @Override protected void onStart() { super.onStart(); Log.d(TAG, "OnStart"); } @Override protected void onResume() { super.onResume(); Log.d(TAG, "onResume"); } @Override protected void onPause() { super.onPause(); Log.d(TAG, "OnPause"); } @Override protected void onStop() { super.onStop(); Log.d(TAG, "onStop"); } @Override protected void onDestroy() { super.onDestroy(); Log.d(TAG, "onDestroy"); } @Override protected void onRestart() { super.onRestart(); Log.d(TAG, "onRestart"); } }
以上步骤完成后,安装到手机,观察LogCat打印出来的消息,对生命周期将一目了然。
自动安装到手机后,LogCat打印出:
点击Start NormalgActivitya按钮后,LogCat打印出:
按下返回键后,LogCat打印出:
点击Start DialogActivitya按钮后,LogCat打印出:
按下返回键后,LogCat打印出:
退出程序后,LogCat打印出:
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原文地址:http://www.cnblogs.com/LGMing/p/4457447.html