Activity小技巧

随时随地退出程序

　　新建一个结合类对所有活动进行管理。

 public class ActivityCollector{
     public static List<Activity> activities = new ArrayList<>();
     public static void addActivity(Activity activity){
         activities.add(activity);
     }
     public static void removeActivity(Acitivity activity){
         activities.remove(acitivity);
     }
     public static void finishAll(){
         for(Activity activity: activities){
             if(!activity.isFinishing()){
                 activity.finish();
             }
         }
     }
 }

启动活动技巧

　　在SecondActivity中添加一个actionStrat（）

 public class SecondActivity extends BaseActivity{
     public static void actionStart(Context context,String data1,String data2){
         Intent intent = new Intent(context,SecondActivity.class);
         intent.putExtra("param1","data1");
         intent.putExtra("param2","data2");
         context.startActivity(intent);
     }
 ......
 }

　　启动SecondActivity

public void onClick(View v){
    SecondActivity.actionStart(FirstAcitivity.this,"data1","data2");
}

　　杀死整个App

/**
 * 退出应用程序
 */
public void AppExit(Context context) {
    try {
        ActivityCollector.finishAll();
        ActivityManager activityMgr = (ActivityManager) context
                .getSystemService(Context.ACTIVITY_SERVICE);
        activityMgr.killBackgroundProcesses(context.getPackageName());
        System.exit();
    } catch (Exception ignored) {}
}  

　　双击退出程序两个方法：

　　1）定义一个变量，来标识是否退出

// 定义一个变量，来标识是否退出
private static boolean isExit = false;
Handler mHandler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        super.handleMessage(msg);
        isExit = false;
    }
};

public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        if (!isExit) {
            isExit = true;
            Toast.makeText(getApplicationContext(), "再按一次退出程序",
                    Toast.LENGTH_SHORT).show();
            // 利用handler延迟发送更改状态信息
            mHandler.sendEmptyMessageDelayed(, );
        } else {
            exit(this);
        }
        return false;
    }
return super.onKeyDown(keyCode, event);}

　　2）保存点击时间：

/保存点击的时间
private long exitTime = 0;
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        if ((System.currentTimeMillis() - exitTime) > 2000) {
            Toast.makeText(getApplicationContext(), "再按一次退出程序",
                    Toast.LENGTH_SHORT).show();
            exitTime = System.currentTimeMillis();
        } else {
                        exit();
                      }
        return false;
    }
        return super.onKeyDown(keyCode, event);
}