WebView中实现延迟加载，图片点击时才加载。

 1         　　String newHtml = html + 
 2                     "<script type=\"text/javascript\">" +
 3                         "(function (){"+
 4                             "var imageList = document.getElementsByTagName(\"img\");"+
 5                             "for(var i=0; i<imageList.length; i++){"+
 6                                 "var image = imageList[i];"+
 7                                 "image.href = image.src;"+
 8                                 "image.src = \"content://com.example.demo/res/def.jpg\";"+
 9                                 "image.alt = \"点击加载图片\";"+
10                                 "image.onclick = function(){"+
11                                     "this.src = this.href;" +
12                                     "return false;"+
13                                 "}"+
14                             "}"+
15                         "}());"+
16                     "</script>";
17　　　　　　　　mWebView.getSettings().setJavaScriptEnabled(true);
18　　　　　　　　mWebView.loadData(newHtml, "text/html; charset=UTF-8", null);

 1 　　@Override
 2     public AssetFileDescriptor openAssetFile(Uri uri, String mode)
 3             throws FileNotFoundException {
 4         String fileName = uri.getLastPathSegment();
 5         try {
 6             return getContext().getAssets().openFd(fileName);
 7         } catch (IOException e) {
 8             e.printStackTrace();
 9             return super.openAssetFile(uri, mode);
10         }
11     }

1 　　　　<provider 
2             android:name="com.example.demo.database.ImageContentProvider"
3             android:authorities="com.example.demo" />

 1 　　　　public WebResourceResponse shouldInterceptRequest(WebView view,
 2                 String url) {
 3             WebResourceResponse response = null;
 4             if (url.contains("def.jpg")) {
 5                 try {
 6                     InputStream image = getAssets().open("def.jpg");
 7                     response = new WebResourceResponse("image/jpeg", "UTF-8", image);
 8                 } catch (IOException e) {
 9                     e.printStackTrace();
10                 }        
11             }
12             return response;
13         }