WebView用法与JS交互(2) 响应webview中的图片点击事件

    // 注入js函数监听
    private void addImageClickListner() {
        // 这段js函数的功能就是，遍历所有的img几点，并添加onclick函数，函数的功能是在图片点击的时候调用本地java接口并传递url过去
        contentWebView.loadUrl("javascript:(function(){"
                + "var objs = document.getElementsByTagName(\"img\"); "
                + "for(var i=0;i<objs.length;i++)  " + "{"
                +"     if(objs[i].src) "
                +"     if(objs[i].src.indexOf(‘display‘)>0)"
                + "    objs[i].onclick=function(){  "
                + "        window.imagelistner.openImage(this.src);  "
                + "    }  " 
                + "}" 
                + "})()");
    }

package com.example.testandroid;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends ActionBarActivity {

    WebView contentWebView;

    @SuppressLint("JavascriptInterface")
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        contentWebView = (WebView) findViewById(R.id.webview);
        // 启用javascript
        contentWebView.getSettings().setJavaScriptEnabled(true);
        // 随便找了个带图片的网站
        contentWebView.loadUrl("http://www.qdaily.com/display/articles/7237");
        // 添加js交互接口类，并起别名 imagelistner
        contentWebView.addJavascriptInterface(new JavascriptInterface(this),
                "imagelistner");
        contentWebView.setWebViewClient(new MyWebViewClient());

    }

    // 注入js函数监听
    private void addImageClickListner() {
        // 这段js函数的功能就是，遍历所有的img几点，并添加onclick函数，函数的功能是在图片点击的时候调用本地java接口并传递url过去
        contentWebView.loadUrl("javascript:(function(){"
                + "var objs = document.getElementsByTagName(\"img\"); "
                + "for(var i=0;i<objs.length;i++)  " + "{"
//                +"window.imagelistner.openImage(objs[i].src)"
                + "    objs[i].onclick=function()  " + "    {  "
                + "        window.imagelistner.openImage(this.src);  "
                + "    }  " 
                + "}" 
                + "})()");
    }

    // js通信接口
    public class JavascriptInterface {

        private Context context;

        public JavascriptInterface(Context context) {
            this.context = context;
        }

        public void openImage(String img) {
            Log.e("mytag", img);
        }
        
        
        public void log(String s){
            Log.e("mytag", s);
        }
    }

    // 监听
    private class MyWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {

            return super.shouldOverrideUrlLoading(view, url);
        }

        @Override
        public void onPageFinished(WebView view, String url) {

            view.getSettings().setJavaScriptEnabled(true);

            super.onPageFinished(view, url);
            // html加载完成之后，添加监听图片的点击js函数
            addImageClickListner();

        }

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            view.getSettings().setJavaScriptEnabled(true);

            super.onPageStarted(view, url, favicon);
        }

        @Override
        public void onReceivedError(WebView view, int errorCode,
                String description, String failingUrl) {

            super.onReceivedError(view, errorCode, description, failingUrl);

        }
    }

}