Android 进度条显示在标题栏的实现方法

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="horizontal"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 >
<Button android:id="@+id/button1" 
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text=" 显示"/>
<Button android:id="@+id/button2"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="隐藏"/>
</LinearLayout>

package com.imooc.progressbarr;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
public class MainActivity extends Activity {
 private Button btn1;
 private Button btn2;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  //设置窗口特征：启用显示进度的进度条
  requestWindowFeature(Window.FEATURE_PROGRESS);
   //设置窗口特征：启用不显示进度的进度条
  requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
  setContentView(R.layout.activity_main);
  Button btn1=(Button)findViewById(R.id.button1);
  Button btn2=(Button)findViewById(R.id.button2);
  btn1.setOnClickListener(new OnClickListener(){
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    //显示不带进度的进度条
    setProgressBarIndeterminateVisibility(true);
    //显示不带进度的进度条
    setProgressBarVisibility(true);
    //设置进度条的进度
    setProgress(4500);
   } 
  });
  btn2.setOnClickListener(new OnClickListener(){
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    //隐藏不带进度的进度条
    setProgressBarIndeterminateVisibility(false);
    //隐藏带进度的进度条
    setProgressBarVisibility(false);
   } 
  });
 }
 @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;
 }
}