从Webview下载文件按钮单击Android

Question

我在做一个项目。在这个项目中，我想在按钮单击（浮动按钮）而不是WebView单击下载文件。我使用Webview点击...

完成了我的任务

wv.setDownloadListener(new DownloadListener() {
       @Override
        public void onDownloadStart(String url, String userAgent,
                                    String contentDisposition,
                                    String mimetype, long contentLength) {
            DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
            request.setMimeType(mimetype);
            String cookies = CookieManager.getInstance().getCookie(url);
            request.addRequestHeader("cookie",cookies);
            request.addRequestHeader("User-Agent",userAgent);
            request.setDescription("Downloading files");
            request.setTitle(URLUtil.guessFileName(url,contentDisposition,
                    mimetype));
            request.allowScanningByMediaScanner();
            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
            request.setDestinationInExternalFilesDir(MainActivity.this, Environment.DIRECTORY_DOWNLOADS,
                    ".mp4");
            DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
            dm.enqueue(request);
            Toast.makeText(MainActivity.this, "Downloading file", Toast.LENGTH_SHORT).show();

        }
    });

我也试试这个......

  private void createDownloadListener() {
    new DownloadListener() {
        @Override
        public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {
            Toast.makeText(MainActivity.this, "this", Toast.LENGTH_SHORT).show();

            DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
            request.setMimeType(mimetype);
            String cookies = CookieManager.getInstance().getCookie(url);
            request.addRequestHeader("cookie", cookies);
            request.addRequestHeader("User-Agent", userAgent);
            request.setDescription("Downloading files");
            request.setTitle(URLUtil.guessFileName(url, contentDisposition,
                    mimetype));
            request.allowScanningByMediaScanner();
            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
            request.setDestinationInExternalFilesDir(MainActivity.this, Environment.DIRECTORY_DOWNLOADS,
                    ".mp4");
            DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
            dm.enqueue(request);
            Toast.makeText(MainActivity.this, "Downloading file", Toast.LENGTH_SHORT).show();
            return;
        }
    };
}

但这不适合我。任何人都可以帮助我..