Android：生命周期案例

浏览数：23 / 时间：2015年06月11日

　　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：

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