android JS互交图片点击事件

activity代码：

@SuppressLint("SetJavaScriptEnabled")  
public class TestInputActivity extends Activity {  
  
    WebView contentWebView;  
  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.input);  
        contentWebView = (WebView) findViewById(R.id.webView);  
        // 启用javascript  
        contentWebView.getSettings().setJavaScriptEnabled(true);  
        // 测试带图的文的网站  
        contentWebView.loadUrl("http://www.12365auto.com/news/2014-07-10/20140710115457.shtml");  
        // 添加js交互接口类，并起别名 webtest  
        contentWebView.addJavascriptInterface(this, "webtest");  
        contentWebView.setWebViewClient(new MyWebViewClient(this));  
    }  
  
    /**  
     * 图片点击之后 webview回调的java本地方法，此时拿到了图片地址，君想干嘛就干嘛了！  
     * 方法名:jsInvokeJava  
     * @param arg  
     */ 

    @JavascriptInterface
    public void jsInvokeJava(String img) {
        Log.i("songe", "被点击的图片地址为：" + img);  
    }

MyWebViewClient类

/**
 * Created by nicholas on 2018/4/4.
 */

public class MyWebViewClient extends WebViewClient {

    private Context con;

    public MyWebViewClient(Context con) {
        this.con = con;
    }

    /**
     * webview开始加载调用此方法
     */
    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
        super.onPageStarted(view, url, favicon);
        Log.i("songe", "webclient :  onPageStarted");
    }
    /**
     * 1-webview 加载完成调用此方法;
     * 2-查找页面中所有的标签，然后动态添加onclick事件;
     * 3-事件中回调本地java的jsInvokeJava方法;
     * 注意：webtest别名和上面contentWebView.addJavascriptInterface(this, "webtest")别名要一致;
     */
    @Override
    public void onPageFinished(WebView view, String url) {
        super.onPageFinished(view, url);
        Log.i("songe", "webclient : onPageFinished");
        //动态注入js
        view.loadUrl(
                "javascript:(function(){"
                        + "  var objs = document.getElementsByTagName(\"img\"); "
                        + "  for(var i=0;i