Android疑问1——Handler的removeCallbacks方法无效？(已经明白了）

　　刚在做复习时发现了一个问题，加入了Handler的线程，即使调用了removeCallbacks线程还是存在，而且退出了Activity之后线程还在运行。难道是removeCallBacks无效？还是我哪里写错了？

package cfuture09.handlerProgress;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.ProgressBar;public class HandlerProgressActivity extends Activity {Button start;ProgressBar progressBar;Handler handler = new Handler() {@Overridepublic void handleMessage(Message msg) {// TODO Auto-generated method stubprogressBar.setProgress(msg.arg1);handler.post(r);}};Runnable r = new Runnable() {int i = 0;@Overridepublic void run() {// TODO Auto-generated method stubSystem.out.println("Begin thread");i += 10;Message msg = handler.obtainMessage();msg.arg1 = i;try {Thread.sleep(1000);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}//if ( i < 100) { handler.sendMessage(msg);//}if ( i >= 100) {handler.removeCallbacks(r);System.out.println("end");}}};    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        start = (Button) findViewById(R.id.start);        progressBar = (ProgressBar) findViewById(R.id.progress);        start.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubprogressBar.setVisibility(ProgressBar.VISIBLE);handler.post(r);}});    }}

　　刚和一个同学聊天说到这一段，跟他一说，忽然之间自己想明白了。原来还是代码的逻辑错误。这段代码我是看视频写的，可能视频的作者在写这段代码时也没注意到这个问题。在看了之后的视频我才想明白。聊天记录用图片贴上来吧。

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