wv.setWebViewClient(new WebViewClient() { 
               @Override 
               public void onPageStarted(WebView view, String url, Bitmap favicon) { 
                 super.onPageStarted(view, url, favicon); 
                 DialogUtils.showUpdateDialog(MainActivity.this, "加载中", "请稍后。。。"); 
               } 
 
               @Override 
               public void onPageFinished(WebView view, String url) { 
                 super.onPageFinished(view, url); 
                 DialogUtils.hideDialog(); 
               } 
 
               @Override 
               public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) { 
                 super.onReceivedError(view, request, error); 
                 Toast.makeText(MainActivity.this, "网页加载错误，请稍后重试", Toast.LENGTH_SHORT).show(); 
               } 
 
               @Override 
               public boolean shouldOverrideUrlLoading(WebView view, String url) { 
                 return true; 
               } 
             }