Android和js代码互相调用

在js中，有如下代码：

<script>
    //js调用安卓
  function sendDataToAndroid(){
    //调用android程序中的方法，并传递参数。
    var name = document.getElementById("name_input").value;
    //注意这里的AndroidWebView和方法名chen
    window.AndroidWebView.chen(name);
  }

  //在android代码中调用js代码
  function dataFromAndroid(msg){
    alert("来自安卓的信息："+msg);
  }
  script>

1、在js中调用安卓的话，安卓中写法：

webView.addJavascriptInterface(new JsInterface_2(context), "AndroidWebView");

private class JsInterface_2 {
        private Context mContext;

        public JsInterface_2(Context context) {
            this.mContext = context;
        }

        //在js中调用window.AndroidWebView.chen(name)，便会触发此方法。
        @JavascriptInterface
        public void chen(String name) {
            Log.e("name==" ,name);
        }
    }

2、安卓调用js中方法，给js传值
注：这个方法要等网页加载完，才有效。所以，要么在网页加载完的监听里调用，要么，写一个点击事件，等加载完了点击调用

传单个值及多个值，见注释

 //网页返回键的处理
        webView.setOnKeyListener(new View.OnKeyListener() {

            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                if (event.getAction() == KeyEvent.ACTION_DOWN) {
                    if (keyCode == KeyEvent.KEYCODE_BACK) {  //表示按返回键时的操作
                        if (webView.canGoBack()) {
                            webView.goBack();   //后退
                        } else {
                        //所在activity销毁
                            finish();
                        }
                        return true;   //已处理
                    }
                }
                return false;
            }
        });


        webView.setWebViewClient(new MyWebViewClient());
        webView.setWebChromeClient(new MyChromeClient());

private class MyChromeClient extends WebChromeClient {
        @Override
        public void onProgressChanged(WebView view, int newProgress) {

            super.onProgressChanged(view, newProgress);
        }

        @Override
        public void onReceivedTitle(WebView view, String title) {
            // TODO Auto-generated method stub
            super.onReceivedTitle(view, title);

            LogU.i("网页title-----" , title);

        }
    }

// webview设置的代理类
    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);
            Log.i("详情页加载完成-----" , url);

            //调用js中的代码，给网页传用户id
            //传多个值的方法。注意单引号的配对
            //webView.loadUrl("javascript:dataFromAndroid('" + userInfo.getUserId()+"','"+userInfo.getUserId() + "')");
            //传单个值
            webView.loadUrl("javascript:dataFromAndroid('" + userInfo.getUserId() + "')");

        }

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            Log.i("详情页开始加载-----" ,url);
            super.onPageStarted(view, url, favicon);
        }

        @Override
        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            Log.i("详情页加载异常-----" , failingUrl);

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

        }
    }