Android中WebView加载网页设置进度条

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical" android:layout_width="match_parent"
  android:layout_height="match_parent">
  <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="48dp"
      android:background="@color/colorPrimary"
      android:layout_weight="0">
      <ImageView
        android:id="@+id/activity_add_authentication_back"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/activity_news_back"
        android:layout_marginLeft="10dp"/>
      <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="网页"
        android:textColor="@color/white"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:textSize="18sp"/>
    </RelativeLayout>
  </LinearLayout>
  <ProgressBar
    android:id="@+id/progressBar1"
    style="?android:attr/progressBarStyleHorizontal"
    android:layout_width="match_parent"
    android:layout_height="3dip"
    android:progressDrawable="@drawable/pg"
    android:visibility="gone" />

  <WebView
    android:id="@+id/web_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

  </WebView>
</LinearLayout>

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

  <item android:id="@android:id/background">
    <shape>
      <corners android:radius="2dp" />
      <gradient
        android:angle="270"
        android:centerColor="#E3E3E3"
        android:endColor="#E6E6E6"
        android:startColor="#C8C8C8" />
    </shape>
  </item>
  <item android:id="@android:id/progress">
    <clip>
      <shape>
        <corners android:radius="2dp" />
        <gradient
          android:centerColor="#4AEA2F"
          android:endColor="#31CE15"
          android:startColor="#5FEC46" />

      </shape>
    </clip>
  </item>

</layer-list>

package com.vimi8.app.activity;

import android.content.Context;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.JavascriptInterface;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.vimi8.app.R;
import com.vimi8.app.framework.ActivityBase;

/**
 * Created by vimi8 on 2017/4/18.
 */

public class YyxText extends ActivityBase {

  private WebView myWebView ;

  private ProgressBar pg1;


  @Override
  protected void initVariables(Bundle savedInstanceState) {

  }

  @Override
  protected int initLayoutViews() {
    return R.layout.yyx_text;
  }

  @Override
  protected void initViewsAndStaticData() {
    //获取webview控件
    myWebView = (WebView) findViewById(R.id.web_view);
    pg1=(ProgressBar) findViewById(R.id.progressBar1);

    //加载服务器上的页面
    myWebView.loadUrl("http://www.baidu.com");
    //加载本地中的html
    //myWebView.loadUrl("file:///android_asset/www/test2.html");
    //加上下面这段代码可以使网页中的链接不以浏览器的方式打开
    myWebView.setWebViewClient(new WebViewClient());
    //得到webview设置
    WebSettings webSettings = myWebView.getSettings();
    //允许使用javascript
    webSettings.setJavaScriptEnabled(true);
    //将WebAppInterface于javascript绑定
    myWebView.addJavascriptInterface(new WebAppInterface(this),"Android");

    //设置经度条
    myWebView.setWebChromeClient(new WebChromeClient(){
      @Override
      public void onProgressChanged(WebView view,int newProgress) {
        // TODO 自动生成的方法存根

        if(newProgress==100){
          pg1.setVisibility(View.GONE);//加载完网页进度条消失
        }
        else{
          pg1.setVisibility(View.VISIBLE);//开始加载网页时显示进度条
          pg1.setProgress(newProgress);//设置进度值
        }

      }
    });

  }


  @Override
  public boolean onKeyDown(int keyCode,KeyEvent event) {
    if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) {
      myWebView.goBack();
      return true;
    }
    return super.onKeyDown(keyCode,event);
  }


  public class WebAppInterface {
    Context mContext;

    /** Instantiate the interface and set the context */
    WebAppInterface(Context c) {
      mContext = c;
    }

    /** Show a toast from the web page */
    @JavascriptInterface
    public void showToast(String toast) {
      Toast.makeText(mContext,toast,Toast.LENGTH_SHORT).show();
    }
  }
}