检查一个WebView是否正在播放视频

Question

检查一个WebView是否正在播放视频

3

有没有可能检查一个WebView是否正在播放视频，如果是的话，获取此视频的http://... .mp4/ URL以便下载？

我已经尝试过这段代码：

public void onLoadResource(WebView view, final String url){
            super.onLoadResource(view, url);
            if(url.endsWith(".mp4") & !url.contains(".jpg") & !url.contains(".png")){

                AlertDialog.Builder video_downloaden = new AlertDialog.Builder(SearchActivity.this);
                video_downloaden.setTitle("Video downloaden?");
                video_downloaden.setMessage("Download Video?");
                video_downloaden.setPositiveButton("YES", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {

                        DownloadManager.Request request_video = new DownloadManager.Request(Uri.parse(url));
                        request_video.allowScanningByMediaScanner();

                        request_video.setVisibleInDownloadsUi(false);

                        DownloadManager downloadManager2 = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);

                        request_video.setDestinationInExternalFilesDir(getApplicationContext(), DIRECTORY_DOWNLOADS, File.separator + ".Videos" + File.separator + "video" + video_number);

                        downloadManager2.enqueue(request_video);
                        Toast.makeText(SearchActivity.this,"Download started",Toast.LENGTH_LONG).show();

                    }
                });
                video_downloaden.setNegativeButton("NO", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        dialogInterface.cancel();
                    }
                });

                video_downloaden.show();

            }
        }

但是使用onLoadResource()时，AlertDialog会一直显示，而且下载不总是有效...所以我的问题是，是否有其他机会检查WebView是否正在播放视频并获取视频网址？

- Nils Be

1个回答

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- mel · Accepted Answer

您可以使用JavaScript检测视频是否正在播放。

Create a .js file in the assets directory and declare a JavaScript function and jQuery like this:
```
$("video").on("play", function() {
 //You can call JavaScriptInterface here.
});
```

Insert this .js file in web page that contains video. I inserted .js file when onPageFinished is called.

view?.context?.assets?.let {
    val inputStream: InputStream = it.open(scriptFile)
    val buffer = ByteArray(inputStream.available())
    inputStream.read(buffer)
    inputStream.close()

    val encoded = Base64.encodeToString(buffer, Base64.NO_WRAP)

    view.loadUrl("javascript:(function() {" +
            "var parent = document.getElementsByTagName('head').item(0);" +
            "var script = document.createElement('script');" +
            "script.type = 'text/javascript';" +
            "script.innerHTML = window.atob('$encoded');" +
            "parent.appendChild(script)" +
            "})()")

If you are not familiar with Kotlin, check this reference: Android Web-View : Inject local Javascript file to Remote Webpage

Done! If you use JavaScriptInterface, you can do whatever you want, like this.

class WebScriptInterface(val button: View) {

 @JavascriptInterface
 fun hideFloatingButton() {
   if (button.visibility == View.VISIBLE) {
    button.visibility = View.GONE
   }
 }
}

设置webView使用 JavaScriptInterface。

webView.addJavascriptInterface
 (WebScriptInterface(binding.floatBrowserCollect), "App")

然后进行调用。

 $("video").on("play", function() {
    App.hideFloatingButton()
  });

我希望能对您有所帮助。