用定时器显示提示对话框出问题？

Question

用定时器显示“sorry”的提示对话框，单独用来提示正常，但用定时器来启动就出现问题。 代码如下，求高人指点：
定时器部分：  
      final Timer  mTimer = new Timer(true); 
        final TimerTask mTimerTask = new TimerTask() 
        {
             public void run()
             {
                    show_alert("sorry", null, "0K");
              }         
         };
    
      
     mTimer.schedule(mTimerTask, 4000);提示对话框部分：
private void show_alert(CharSequence title, String message, CharSequence button)
    {
     AlertDialog.Builder alert = new AlertDialog.Builder(this);
     alert.setTitle(title);
     alert.setMessage(message);
     alert.setPositiveButton(button, 
     new DialogInterface.OnClickListener() 
{
@Override
public void onClick(DialogInterface dialog, int i) 
{
;
}
});
     alert.show();
    } 

Answer 1

Timer 要和 Handler 一起使用，代码如下：
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main); Timer mTimer = new Timer(true);
mTimer.schedule(new Task(), 4000);
}

private class Task extends TimerTask{
@Override
public void run() {
Message msg = new Message();
        msg.arg1 = 1;
        handler.sendMessage(msg);
}
}

private Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
switch(msg.arg1){
case 1:
show_alert("sorry", null, "0K");
}
super.handleMessage(msg);
}
}; private void show_alert(CharSequence title, String message,
CharSequence button) {
AlertDialog.Builder alert = new AlertDialog.Builder(this);
alert.setTitle(title);
alert.setMessage(message);
alert.setPositiveButton(button, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int i) {
;
}
});
alert.show();
}

Answer 2

不能在非UI线程操作UI，因此要用handler配合显示，具体方法参见1楼

Answer 3

           Timer timer = new Timer();      
            Handler handler = new Handler(){      
             
               public void handleMessage(Message msg) {      
                   switch (msg.what) {          
                   case 1:          
                        Intent intent=new Intent();   
                        intent.setClass(Bf_mech_lpener_1.this, bf_mech_1_1opener.class);   
                        startActivity(intent);   
                        Bf_mech_lpener_1.this.finish();      
                        break;          
                    }          
                    super.handleMessage(msg);      
           }      
                      
            };      
            TimerTask task = new TimerTask(){      
             
                public void run() {      
                    Message message = new Message();          
                    message.what = 1;          
                    handler.sendMessage(message);        
                }      
                      
           };      
      
    @Override  
    public void onCreate(Bundle savedInstanceState)   
    {   
        super.onCreate(savedInstanceState);   
        SharedPreferences sp = getSharedPreferences("player_information",0);   
        strPlayerName=sp.getString("Player_name", "");   
        if(strPlayerName.equals(""))   
        {   
            setContentView(R.layout.bf_mech_opener_one);   
            OpenFlash = (ImageView) findViewById(R.id.bf_mech_open_light1);     
            OpenFlash.setBackgroundResource(R.anim.open_flash);    
            Open_animation = (AnimationDrawable) OpenFlash.getBackground();   
            //5秒钟后自动跳到下一个页面timer.schedule(task, 5000);      
               
        }   
        else {   
            Intent intent=new Intent(Bf_mech_lpener_1.this,Home_2.class);   
            startActivity(intent);   
            Bf_mech_lpener_1.this.finish();      
        }   
           
    }   
    //按向上键，启动动画   
    public boolean onKeyUp(int KeyCode,KeyEvent event)   
    {   
        switch(KeyCode)   
        {   
          case KeyEvent.KEYCODE_DPAD_UP:   
               Open_animation.start();   
               break;          
        }   
        return true;   
           
    }   
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/TQUDING/archive/2010/08/06/5793067.aspx

Answer 4

正解，Android中需要配合Handler来实现Timer功能的，与我们平时Java的编写习惯有些差异