AndroidWebView的使用

android Webview 的使用

PRivate WebSettings webSettings;private javaScriptInterface JavascriptInterface;
javascriptInterface = new JavaScriptInterface(this);webSettings = webView.getSettings();//是否支持jswebSettings.setJavaScriptEnabled(true);// 设置支持缩放webSettings.setSupportZoom(true);//显示图片时自适应屏幕大小,但是4.4以前好用,4,4以后不好用//mWebView.getSettings().setLayoutAlgorithm(WebSettings.LayoutAlgorithm.SINGLE_COLUMN);//weView中有链接,在当前 browser 中相应webView.setWebViewClient(new MyWebViewClient());//设置进度条,处理提示框webView.setWebChromeClient(new MyWebChromeClient());//添加监听webView.addJavascriptInterface(javascriptInterface, "imagelistner");webView.loadDataWithBaseURL(null,bean.getContent(), "text/html", "utf-8", null);
// js通信接口public static class JavaScriptInterface {    private Context context;    public JavaScriptInterface(Context context) {        this.context = context;    }    //点击图片回调方法    //必须添加注解,否则无法响应    @JavascriptInterface    public void openImage(final String img) {        System.out.println(img);        Log.i("TAG", "响应点击事件!");        Intent intent = new Intent();        intent.putExtra("image", img);        System.out.println(img);        ((Activity) mContext).runOnUiThread(new Runnable() {            @Override            public void run() {                showImg(img);            }        });    }    public void showImg(final String img) {        final AlertDialog dialog = new AlertDialog.Builder(mContext).create();        final ImageView imgView = getImageView();        Glide.with(mContext).load(img).placeholder(R.mipmap.loading_placeholder_img).crossFade().into(imgView);        dialog.setView(imgView);        dialog.show();        imgView.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                dialog.dismiss();            }        });    }    private ImageView getImageView() {        ImageView imgView = new ImageView(mContext);        imgView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));        imgView.setScaleType(ImageView.ScaleType.FIT_XY);        return imgView;    }}
private class MyWebViewClient extends WebViewClient {    @Override    public void onPageFinished(WebView view, String url) {        super.onPageFinished(view, url);        // html加载完成之后，添加监听图片的点击js函数        addImageClickListner();        imgReset();    }    @Override    public boolean shouldOverrideUrlLoading(WebView view, String url) {        view.loadUrl(url);        return true;    }}/** * 循环遍历标签中的图片 * js 语法 */private void imgReset() {    webView.loadUrl("javascript:(function(){" +            "var objs = document.getElementsByTagName('img'); " +            "for(var i=0;i<objs.length;i++)  " +            "{" + "var img = objs[i];   " +            "    img.style.maxWidth = '100%';   " +            "}" +            "})()");}/** * 设置进度条和提示框 */private class MyWebChromeClient extends WebChromeClient {    //该方法中可以设置进度条    @Override    public void onProgressChanged(WebView view, int newProgress) {        super.onProgressChanged(view, newProgress);    }    //发方法中可以处理提示框    @Override    public boolean onJsAlert(WebView view, String url, String message, JsResult result) {        return super.onJsAlert(view, url, message, result);    }}// 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    webView.loadUrl("javascript:(function(){" +            "var objs = document.getElementsByTagName(/"img/"); " +            "for(var i=0;i<objs.length;i++)  " +            "{" + "    objs[i].onclick=function()  " +            "    {  " + "        window.imagelistner.openImage(this.src);  " +            "    }  " +            "}" +            "})()");}