Android与JS互相调

private void initWebbiew() {
        WebSettings webSettings = webview_aboutus.getSettings();
        //设置WebView属性，能够执行Javascript脚本
        webSettings.setJavaScriptEnabled(true);
        //设置可以访问文件
        webSettings.setAllowFileAccess(true);
        //设置支持缩放
        webSettings.setBuiltInZoomControls(true);
        //用来处理一些html的页面内容
        webview_aboutus.setWebViewClient(new webViewClient());
        //丰富的处理效果，比如JS、进度条等
        webview_aboutus.setWebChromeClient(new WebChromeClient());
 
//        webview_aboutus.getSettings().setDefaultTextEncodingName("UTF -8");
    }
 
      /**
     * 使用与API17以上
     *
     * @param context
     */
    @SuppressLint("JavascriptInterface")
    public void setDoWhatListener(Context context) {
        // 添加js交互接口类，并起别名 appdowhat
        JavascriptInterface javascriptInterface = new JavascriptInterface(context);
        webview_aboutus.addJavascriptInterface(javascriptInterface, javascriptInterface.toString());
    }
 
     // 注入js函数监听
    private void infoHtmoJS() {
        // 这段js函数的功能就是，获取控件高度并传入值
        //scrollContent 换成div
        /**
         *  <div class="m-detail-dynamic">
          * <section class="dynamic-content">
         *  <div id="content">
         */
         webview_aboutus.loadUrl("javascript:(function(){" +
                    "var _height = document.body.offsetHeight;"
                    + "window.appdowhat.appDoWhat(_height);"
                    + "})()");
    }
 
    // js通信接口
    public class JavascriptInterface {
 
        private Context context;
 
        public JavascriptInterface(Context context) {
            this.context = context;
        }
 
        @android.webkit.JavascriptInterface
        public void appDoWhat(int  height) {
            webview_aboutus.setLayoutParams(new LinearLayout.LayoutParams(DisplayUtil.getDensityWdith(context), (int) (height * DisplayUtil.getDensity(context))));
        }
 
        @android.webkit.JavascriptInterface
        public String toString() {
            return "appdowhat";
        }
    }
 
    public class WebChromeClient extends android.webkit.WebChromeClient {
        @Override
        public void onProgressChanged(WebView view, int newProgress) {
            if (newProgress == 100) {
//                dismissDialog();
            } else {
//                showWaitDialog();
            }
            super.onProgressChanged(view, newProgress);
        }
    }
 
    //Web视图
    private class webViewClient extends WebViewClient {
        @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
        public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest st) {
            view.loadUrl(st.getUrl().toString());
            return true;
        }
 
        @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js函数
            infoHtmoJS();
        }
 
        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            view.getSettings().setJavaScriptEnabled(true);
            super.onPageStarted(view, url, favicon);
        }
    }

public void javaCallJsNoParams(View view){
  //直接加载(javascript：javaCallJsNoParamsMethod()) 
  //javascript：方法名()
        webView.loadUrl(javascript:javaCallJsNoParamsMethod());
    }
 
    public void javaCallJsHasParams(View view){
        webView.loadUrl(javascript:javaCallJsHasParamsMethod(' + 123 + '));
    }
 
    <script>
   function javaCallJsNoParamsMethod(){
      alert("hello world!");
   }
   function javaCallJsHasParamsMethod(a){
      alert('hello in android!');
   }
   </script>