<Button 
    android:id="@+id/button1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true" 
    android:layout_centerHorizontal="true" 
    android:layout_marginTop="104dp" 
    android:onClick="doAsyncTask" 
    android:text="开始" /> 

 public class MainActivity extends Activity { 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    System.out.println("onCreate" + Thread.currentThread().getId()); 
  } 
  public void doAsyncTask(View view){ 
    new InnerAsyncTask().execute(""); 
  } 
  private class InnerAsyncTask extends AsyncTask<Object, Object, Object>{ 
    @Override 
    protected Object doInBackground(Object... params) { 
      for(int i = 0; i < 30;i++){ 
        System.out.println("InnerAsyncTask" + Thread.currentThread().getId()); 
        try { 
          Thread.sleep(1000); 
        } catch (InterruptedException e) { 
          e.printStackTrace(); 
        } 
      } 
      return null; 
    } 
  } 
} 

<Button 
   android:id="@+id/button1" 
   android:layout_width="wrap_content" 
   android:layout_height="wrap_content" 
   android:layout_alignParentTop="true" 
   android:layout_centerHorizontal="true" 
   android:layout_marginTop="104dp" 
   android:onClick="doAsyncTask" 
   android:text="开始" /> 
 
 <ImageView 
   android:id="@+id/imageView1" 
   android:layout_width="wrap_content" 
   android:layout_height="wrap_content" 
   android:layout_below="@+id/button1" 
   android:layout_centerHorizontal="true" 
   android:layout_marginTop="22dp" 
   android:src="@drawable/abs" /> 

 public class MainActivity extends Activity { 
  private ImageView image; 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
     image = (ImageView) findViewById(R.id.imageView1);  
//   System.out.println("onCreate" + Thread.currentThread().getId()); 
  } 
  public void doAsyncTask(View view){ 
    new InnerAsyncTask().execute(""); 
  } 
  private class InnerAsyncTask extends AsyncTask<String,Integer, Bitmap>{ 
    @Override 
    protected Bitmap doInBackground(String... params) { 
      try { 
        Thread.sleep(3000); 
      } catch (InterruptedException e) { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
      } 
      return BitmapFactory.decodeResource(getResources(), R.drawable.abc); 
    } 
     @Override 
    protected void onPostExecute(Bitmap result) { 
      image.setImageBitmap(result);     
    } 
  } 
} 

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  xmlns:tools="http://schemas.android.com/tools" 
  android:layout_width="match_parent" 
  android:layout_height="match_parent" > 
  <TextView  
    android:id="@+id/tv_pb" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="100%" 
    android:visibility="gone" 
    android:textSize="16sp"/> 
 
  <Button 
    android:id="@+id/btn_update" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true" 
    android:layout_centerHorizontal="true" 
    android:layout_marginTop="104dp" 
    android:onClick="doAsyncTask" 
    android:text="开始" /> 
 
  <ImageView 
    android:id="@+id/iv_image" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_below="@+id/btn_update" 
    android:layout_centerHorizontal="true" 
    android:layout_marginTop="22dp" 
    android:src="@drawable/abs" /> 
 
  <ProgressBar 
    android:id="@+id/pb_progress" 
    style="?android:attr/progressBarStyleHorizontal" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true" 
    android:max="100" 
    android:visibility="gone" 
    android:layout_alignRight="@+id/btn_update" 
    android:layout_marginTop="32dp" /> 
  
</RelativeLayout> 

public class LoadImage extends AsyncTask<String, Integer, Object> { 
  private Context context; 
  private ImageView imageview; 
  private Bitmap image; 
  private Button button; 
  private ProgressBar pg; 
  private TextView tv; 
  public LoadImage(Context context, Button button, ImageView imageview, 
      ProgressBar pg, TextView tv) { 
    this.context = context; 
    this.imageview = imageview; 
    this.button = button; 
    this.pg = pg; 
    this.tv = tv; 
  } 
  @Override 
  protected Object doInBackground(String... params) { 
    for (int i = 0; i <= 100; i++) { 
      publishProgress(i); 
    try { 
      Thread.sleep(50); 
    } catch (InterruptedException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
    } 
    } 
    image = BitmapFactory.decodeResource(context.getResources(), 
        R.drawable.abc); 
    return null; 
  } 
  @Override 
  protected void onProgressUpdate(Integer... values) { 
    // TODO Auto-generated method stub 
    pg.setProgress(values[0]); 
    tv.setText(values[0] + "%"); 
  } 
  @Override 
  protected void onPostExecute(Object result) { 
    imageview.setImageBitmap(image); 
    button.setEnabled(true); 
    pg.setVisibility(View.GONE); 
    tv.setVisibility(View.GONE); 
  } 
} 

 public class MainActivity extends Activity { 
  private ImageView image; 
  private Button button; 
  private ProgressBar pg; 
  private TextView tv;  
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
     image = (ImageView) findViewById(R.id.iv_image);   
     button = (Button) findViewById(R.id.btn_update); 
     pg = (ProgressBar) findViewById(R.id.pb_progress); 
     tv = (TextView) findViewById(R.id.tv_pb); 
  } 
  public void doAsyncTask(View view){ 
    button.setEnabled(false); 
    pg.setVisibility(View.VISIBLE); 
    tv.setVisibility(View.VISIBLE); 
    new LoadImage(this,button,image,pg,tv).execute(""); 
  } 
}