//在指定的时间执行指定的任务。
 public void schedule(TimerTask task, Date when) {}
 //延迟指定时间后执行指定的任务
 public void schedule(TimerTask task, long delay) {}
 //按设置延迟时间和时间间隔重复执行指定的任务
 public void schedule(TimerTask task, long delay, long period) {}
 //在指定的时间和时间间隔重复执行指定的任务
 public void schedule(TimerTask task, Date when, long period) {}

import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;
public class MainActivity extends Activity {
 private ProgressBar progressbar;
 private Activity _rootActivity;
 private WebView webView;
 private WebClient webClient;
 private Timer timer = new Timer();
 private int currentProgress = 0;
 String url = "http://appagent.gyfc.net.cn/NewHouse/index";
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  progressbar = (ProgressBar) findViewById(R.id.web_progressbar);
  webView = (WebView) findViewById(R.id.webView);
  webClient = new WebClient();
  webView.setWebViewClient(webClient);
  webView.setWebChromeClient(new WebChromeClient(){
   @Override
   public void onProgressChanged(WebView view, int newProgress) {
    super.onProgressChanged(view, newProgress);
    if (newProgress == 100) {
     stopTimeTask();
     progressbar.setVisibility(View.GONE);
    } else {
     if (newProgress > currentProgress) {
      progressbar.setProgress(newProgress);
      currentProgress = newProgress;
     }
    }
   }
  });
  findViewById(R.id.btn).setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    webView.loadUrl(url);
   }
  });
 }
 class WebClient extends WebViewClient{
  @Override
  public void onPageStarted(WebView view, String url, Bitmap favicon) {   super.onPageStarted(view, url, favicon);
   startTimeTask();
  }
  @Override
  public void onPageFinished(WebView view, String url) {
   // TODO Auto-generated method stub
   super.onPageFinished(view, url);
   stopTimeTask();
  }
 }
 /**
  * 启动定时器
  */
 private void startTimeTask() {
  stopTimeTask();
  timer = new Timer();
  timer.schedule(new TimerTask() {
   @Override
   public void run() {
    runOnUiThread(new Runnable() {
     @Override
     public void run() {
      // TODO Auto-generated method stub
      if (currentProgress < 90) {
       currentProgress += 1;
       progressbar.setProgress(currentProgress);
      } else {
       stopTimeTask();
      }
     }
    });
   }
  }, 0, 50);
 }
 /**
  * 关闭定时器
  */
 private void stopTimeTask() {
  if (timer != null) {
   timer.cancel();
   timer = null;
  }
 }
}

<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"
 android:orientation="vertical" >
  <ProgressBar
   android:id="@+id/web_progressbar"
   style="?android:attr/progressBarStyleHorizontal"
   android:layout_width="match_parent"
   android:layout_height="3dp"
   android:progressDrawable="@drawable/progressbar_bg_style" />
  <WebView
   android:id="@+id/webView"
   android:layout_below="@id/web_progressbar"
   android:layout_width="match_parent"
   android:layout_height="match_parent" />
  <Button 
   android:id="@+id/btn"
   android:layout_width="match_parent"
   android:layout_height="40dp"
   android:text="加载网页"
   android:layout_alignParentBottom="true"
   android:background="#e5e5e5"/>
</RelativeLayout>