Android应用技巧之 退出程序功能

package com.common;

import java.util.LinkedList;

import java.util.List;

import android.app.Activity;

import android.app.Application;

 

public class SysApplication extends Application { 

    private List mList = new LinkedList(); 

    private static SysApplication instance; 

 

    private SysApplication() {   

    } 

    public synchronized static SysApplication getInstance() { 

        if (null == instance) { 

            instance = new SysApplication(); 

        } 

        return instance; 

    } 

    // add Activity  

    public void addActivity(Activity activity) { 

        mList.add(activity); 

    } 

 

    public void exit() { 

        try { 

            for (Activity activity : mList) { 

                if (activity != null) 

                    activity.finish(); 

            } 

        } catch (Exception e) { 

            e.printStackTrace(); 

        } finally { 

            System.exit(0); 

        } 

    } 

    public void onLowMemory() { 

        super.onLowMemory();     

        System.gc(); 

    }  

}

用时，在每个Activity启动时，在onCreate方法中用 SysApplication.getInstance().addActivity(this);加入到最后销毁的集合中，要启用退出功能时，用SysApplication.getInstance().exit();即可finish所有的Activity，如下：

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.aboutme);

SysApplication.getInstance().addActivity(this); 

}