根据前面的自己写了一个测试程序:

MainActivity.java如下:

package com.example.androidasynctaskdemos;import android.os.AsyncTask;import android.os.Bundle;import android.app.Activity;import android.util.Log;import android.view.Menu;import android.widget.TextView;public class MainActivity extends Activity {    private final static String TAG="MainActivity";        private myTask tasker;    private TextView mText;        @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                mText=(TextView)findViewById(R.id.text_view);        mText.setText("start");        tasker=new myTask();                tasker.execute("","","");//开始执行            }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.main, menu);        return true;    }    public class myTask extends AsyncTask
     
       {        @Override        protected String doInBackground(String... arg0) {            // TODO Auto-generated method stub            Log.i(TAG,"doInBackground");                        for(int i=1;i<1000;i++){                publishProgress(i);//通知更新UI信息                try {                    Thread.sleep(250);//每隔250ms更新一次UI                } catch (InterruptedException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }            return null;        }        @Override        protected void onPostExecute(String result) {            // TODO Auto-generated method stub            super.onPostExecute(result);                        //这里将在doInBackground全部执行完成后开始执行        }        @Override        protected void onPreExecute() {            // TODO Auto-generated method stub            super.onPreExecute();            Log.i(TAG,"onPreExecute");            //启动任何之前首先执行的地方,可以用于初始化UI信息        }        @Override        protected void onProgressUpdate(Integer... values) {            // TODO Auto-generated method stub            super.onProgressUpdate(values);            Log.i(TAG,"onProgressUpdate");            mText.setText("result : "+values[0]);//实时更新UI处        }                            }}
     

布局文件: