1 package com.zhangmeng.xml; 2  3 import android.os.AsyncTask; 4 import android.widget.ProgressBar; 5 import android.widget.TextView; 6  7 /** 8  * Created by zhangmeng on 2016/10/6. 9  */10 11 public class MyAsync extends AsyncTask<Integer,Integer,String> {12      private ProgressBar bar;13      private TextView tv;14 15     public MyAsync(ProgressBar bar,TextView tv) {16         super();17         this.bar = bar;18         this.tv=tv;19     }20 21     @Override22     protected void onPreExecute() {23         super.onPreExecute();24         tv.setText("The file is downloading! Please wait....");25     }26 27 28 29 30 31     @Override32     protected String doInBackground(Integer... params) {33         DelayOperator delayOperator=new DelayOperator();34         int i;35         for (i = 1; i <1000000; i++) {36             delayOperator.delay(params[0]);37             publishProgress(i);38         }39 40         return i + params[0].intValue() + "";41     }42 43 44     @Override45     protected void onProgressUpdate(Integer... values) {46         bar.setProgress(values[0]);47 48     }49 }

 1 package com.zhangmeng.xml; 2 import android.support.v7.app.AppCompatActivity; 3 import android.os.Bundle; 4 import android.view.View; 5 import android.widget.Button; 6 import android.widget.ProgressBar; 7 import android.widget.TextView; 8  9 public class MainActivity extends AppCompatActivity {10 11     private Button bt;12     private TextView textView;13     private ProgressBar bar;14 15     @Override16     protected void onCreate(Bundle savedInstanceState) {17         super.onCreate(savedInstanceState);18         setContentView(R.layout.activity_main);19         bt= (Button) findViewById(R.id.btn);20         textView=(TextView) findViewById(R.id.tv);21         bar=(ProgressBar) findViewById(R.id.pb);22         bt.setOnClickListener(new View.OnClickListener() {23             @Override24             public void onClick(View v) {25                 MyAsync async=new MyAsync(bar,textView);26                 async.execute(100);27             }28         });29 30 31 32     }33 34 35 36 }

 1 package com.zhangmeng.xml; 2  3 /** 4  * Created by zhangmeng on 2016/10/5. 5  */ 6  7 public class DelayOperator { 8     public void delay(int time){ 9         try {10             Thread.sleep(time);11         } catch (InterruptedException e) {12             e.printStackTrace();13         }14     }15 }