android 完全退出应用程序

android退出应用程序会调用android.os.Process.killProcess(android.os.Process.myPid())或是System.exit(0)，这只是针对第一个Activity(也就是入口的Activity)时生效。如果有A,B,C三个Activity,而想在B或C中Activity退出，调用上面的方法，往往会销毁当前的Activity返回上一个Activity。当然也可以逐个返回上一个Activity，直到跳转到入口的Activity，最后退出应用程序。但这样比较麻烦，而且逐个返回的体验并不友好。

网上比较流行的方法是定义栈，写一个ExitApplication类，利用单例模式管理Activity，在每个在Activity的onCreate()方法中调用ExitApplication.getInstance().addActivity(this)方法,在退出时调用ExitApplication.getInstance().exit()方法，就可以完全退出应用程序了。

ExitApplication类

代码如下：

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import java.util.LinkedList;

import java.util.List;

import android.app.Activity;

import android.app.Application;

public class ExitApplication extends Application
{

private List
activityList = new LinkedList();

private static ExitApplication
instance;

private ExitApplication()

{

}

//单例模式中获取唯一的ExitApplication实例

public static ExitApplication
getInstance()

{

if(null ==
instance)

{

instance = new ExitApplication();

}

return instance;

}

//添加Activity到容器中

public void addActivity(Activity
activity)

{

activityList.add(activity);

}

//遍历所有Activity并finish

public void exit()

{

for(Activity
activity:activityList)

{

activity.finish();

}

System.exit(0);

}

}

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import java.util.LinkedList;

import java.util.List;

import android.app.Activity;

import android.app.Application;

public class ExitApplication extends Application {

private List activityList = new LinkedList();

private static ExitApplication instance;

private ExitApplication()

{

}

//单例模式中获取唯一的ExitApplication实例

public static ExitApplication getInstance()

{

if(null == instance)

{

instance = new ExitApplication();

}

return instance;

}

//添加Activity到容器中

public void addActivity(Activity activity)

{

activityList.add(activity);

}

//遍历所有Activity并finish

public void exit()

{

for(Activity activity:activityList)

{

activity.finish();

}

System.exit(0);

}

}

下面的三个类IndexActivity, BActivity,CActivity是简单的例子，分别是IndexActivity–>BActivity–>CActivity的跳转顺序。在每个Activity类中onCreate()方法中调用ExitApplication.getInstance().addActivity(Activity activity)方法。在任何一个Activity界面退出应用程序时，只要调用ExitApplication.getInstance().exit()方法，就可以在任何一个Activity中完全退出应用程序。

IndexActivity 类源代码：

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import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class IndexActivity extends Activity
{

/**
Called when the activity is first created. */

@Override

public void onCreate(Bundle
savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

Button next=(Button)findViewById(R.id.next_to_b);

next.setOnClickListener(nextClick);

Button exit=(Button)findViewById(R.id.exit_main);

exit.setOnClickListener(exitClick);

ExitApplication.getInstance().addActivity(this);

}

OnClickListener nextClick=new OnClickListener()
{

@Override

public void onClick(View
v) {

//
TODO Auto-generated method stub

Intent intent=new Intent(IndexActivity.this,BActivity.class);

startActivity(intent);

}

};

OnClickListener exitClick=new OnClickListener()
{

@Override

public void onClick(View
v) {

//
TODO Auto-generated method stub

ExitApplication.getInstance().exit();

}

};

}

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import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class IndexActivity extends Activity {

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

Button next=(Button)findViewById(R.id.next_to_b);

next.setOnClickListener(nextClick);

Button exit=(Button)findViewById(R.id.exit_main);

exit.setOnClickListener(exitClick);

ExitApplication.getInstance().addActivity(this);

}

OnClickListener nextClick=new OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

Intent intent=new Intent(IndexActivity.this,BActivity.class);

startActivity(intent);

}

};

OnClickListener exitClick=new OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

ExitApplication.getInstance().exit();

}

};

}

BActivity 类源代码：

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import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class BActivity extends Activity
{

@Override

protected void onCreate(Bundle
savedInstanceState) {

//
TODO Auto-generated method stub

super.onCreate(savedInstanceState);

setContentView(R.layout.b);

Button
next_to_c=(Button)findViewById(R.id.next_to_c);

next_to_c.setOnClickListener(next_to_cClick);

Button
exit_b=(Button)findViewById(R.id.exit_b);

exit_b.setOnClickListener(exitClick);

ExitApplication.getInstance().addActivity(this);

}

OnClickListener
next_to_cClick=new OnClickListener()
{

@Override

public void onClick(View
v) {

//
TODO Auto-generated method stub

Intent
intent=new Intent(BActivity.this,CActivity.class);

startActivity(intent);

}

};

OnClickListener
exitClick=new OnClickListener()
{

@Override

public void onClick(View
v) {

//
TODO Auto-generated method stub

ExitApplication.getInstance().exit();

}

};

}

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import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class BActivity extends Activity {

@Override

protected void onCreate(Bundle savedInstanceState) {

// TODO Auto-generated method stub

super.onCreate(savedInstanceState);

setContentView(R.layout.b);

Button next_to_c=(Button)findViewById(R.id.next_to_c);

next_to_c.setOnClickListener(next_to_cClick);

Button exit_b=(Button)findViewById(R.id.exit_b);

exit_b.setOnClickListener(exitClick);

ExitApplication.getInstance().addActivity(this);

}

OnClickListener next_to_cClick=new OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

Intent intent=new Intent(BActivity.this,CActivity.class);

startActivity(intent);

}

};

OnClickListener exitClick=new OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

ExitApplication.getInstance().exit();

}

};

}

CActivity 类源代码：

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import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class CActivity extends Activity{

@Override

protected void onCreate(Bundle
savedInstanceState) {

//
TODO Auto-generated method stub

super.onCreate(savedInstanceState);

setContentView(R.layout.c);

Button
exit_c=(Button)findViewById(R.id.exit_c);

exit_c.setOnClickListener(exitClick);

ExitApplication.getInstance().addActivity(this);

}

OnClickListener
exitClick=new OnClickListener()
{

@Override

public void onClick(View
v) {

//
TODO Auto-generated method stub

ExitApplication.getInstance().exit();

//如果只是调用以下其中的一个方法，并不会完全退出应用

//android.os.Process.killProcess(android.os.Process.myPid());

//System.exit(0);

}

};

}