android中Activity的管理及程序的退出

界面操作类

public class FirstActivity 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();  
//如果程序当中有多个Activity，在非首个Activity中调用以下其中的一个方法，
//则并不会完全退出应用，而是返回前一个Activity  
//android.os.Process.killProcess(android.os.Process.myPid());  
//System.exit(0);  
}  
};  

}

单例管理类

package com.exit.demo;

import java.util.LinkedList;
import java.util.List;
import android.app.Activity;
import android.app.Application;

public class ExitApplication extends Application {
private List<Activity> activityList = new LinkedList<Activity>();
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);
}
}