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();
 }
 }
}