Asynctask and onclicklistener android 2.3.3 versus 3.2

Question

在我的nexus One (android 2.3.3)上，以下程序的行为与我的xoom (android 3.2)不同:

public class TestOnclickWithAsyncTask extends Activity {
private int mClicked = 0;
private final static String TAG = "TestOnclickWithAsyncTask";
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main);
    RelativeLayout relativeLayout= (RelativeLayout) findViewById(R.id.img_control_panel);
    final Button button = new Button(this);
    button.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            mClicked++;
            Log.i (TAG, "Clicked "+ mClicked + " times");
        }
    });
    relativeLayout.addView(button);

    new LongTask().execute();
}
private class LongTask extends AsyncTask<Void , Void, Void> {
    private ProgressDialog dialog;
      protected void onPreExecute() {
      dialog = new  ProgressDialog(TestOnclickWithAsyncTask.this);
      dialog.setMessage("Waiting ");
      dialog.setIndeterminate(true); 
      dialog.setCancelable(true); 
      try {
          dialog.show();
      } catch (Exception e){}
      }
        protected Void doInBackground(Void... notused) {
                try {
                    Thread.sleep (30000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }//do long task
            return null;
        }

        protected void onPostExecute(Void unusedg) { 
            dialog.dismiss();
            Log.i (TAG,"Long task finished");
        }
}
}

在我的Nexus上，我不能按按钮，而asynctask正在运行(期望的行为):

09-26 00:45:34.361: INFO/TestOnclickWithAsyncTask(3803): Long task finished
09-26 00:45:36.463: INFO/TestOnclickWithAsyncTask(3803): Clicked 1 times
09-26 00:45:36.814: INFO/TestOnclickWithAsyncTask(3803): Clicked 2 times
09-26 00:45:37.975: INFO/TestOnclickWithAsyncTask(3803): Clicked 3 times
09-26 00:45:38.435: INFO/TestOnclickWithAsyncTask(3803): Clicked 4 times

在我的房间里，我只要按一下按钮，进度指示就消失了。

09-26 00:49:05.440: INFO/TestOnclickWithAsyncTask(5887): Clicked 1 times
09-26 00:49:06.230: INFO/TestOnclickWithAsyncTask(5887): Clicked 2 times
09-26 00:49:06.580: INFO/TestOnclickWithAsyncTask(5887): Clicked 3 times
09-26 00:49:06.840: INFO/TestOnclickWithAsyncTask(5887): Clicked 4 times
09-26 00:49:08.170: INFO/TestOnclickWithAsyncTask(5887): Clicked 5 times
09-26 00:49:08.560: INFO/TestOnclickWithAsyncTask(5887): Clicked 6 times
09-26 00:49:30.960: INFO/TestOnclickWithAsyncTask(5887): Long task finished 
09-26 00:49:32.800: INFO/TestOnclickWithAsyncTask(5887): Clicked 7 times
09-26 00:49:33.810: INFO/TestOnclickWithAsyncTask(5887): Clicked 8 times

为什么这不同?更重要的是，我如何防止xoom取消进度对话框?

Answer 1

当你不希望它那样时，为什么要调用setCancelable(true) ?也许这会解决你的问题…

提示:

try {
    dialog.show();
} catch (Exception e) {
}

你为什么要这么做?
1. 在try ... catch中包含带有一般异常捕获而没有反应的代码是一个非常坏的习惯。当你这样做的时候，你应该留下评论，并给出一个很好的理由。