我如何在Android的webview上下载pdf？ [重复]

Question

这个问题在这里已有答案：

• How i can enable to Download PDF via Webview 1回答

从活动的oncreate（）调用此方法。我应该编写什么代码才能进行下载？目前，从此代码中可以看到webview，其中有两个按钮。点击它们后，下载不会发生。请帮忙

private void openBrowser() 
{
    Uri uri = Uri.parse("googlechrome://navigate?url=" + urlString + mSelectedProductDetails.getTransIdValue());
    Intent i = new Intent(Intent.ACTION_VIEW, uri);
    // final String message;
    if (i.resolveActivity(getActivity().getPackageManager()) == null) {
        i.setData(Uri.parse(urlString + mSelectedProductDetails.getTransIdValue()));
        message = urlString + mSelectedProductDetails.getTransIdValue();
    }else 
    {
        message = urlString+mSelectedProductDetails.getTransIdValue();}
        webView.setWebViewClient(new WebViewClient());
        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().getJavaScriptEnabled();
        webView.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
        progress.setVisibility(View.INVISIBLE);
        webView.loadUrl(message);
    }
}

Answer 1

要下载文件，您需要在WebView中实现DownloadListener。

webView.setDownloadListener(new DownloadListener() {

    @Override
    public void onDownloadStart(String url, String userAgent,
                                String contentDisposition, String mimetype,
                                long contentLength) {

        mUrl = url;
        mUserAgent = userAgent;
        mContentDisposition = contentDisposition;
        mMimetype = mimetype;
        mContentLength = contentLength;

        if (isStoragePermissionGranted()) {
            downloadFile(url, userAgent, contentDisposition, mimetype, contentLength);
        }
    }
});

下载您的文件

public void downloadFile(String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {
    DownloadManager.Request request = new DownloadManager.Request(
            Uri.parse(url));

    request.allowScanningByMediaScanner();
    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED); //Notify client once download is completed!
    request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS,
            (URLUtil.guessFileName(url, contentDisposition, mimetype)));
    DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
    dm.enqueue(request);
    Toast.makeText(getApplicationContext(), "Downloading File", //To notify the Client that the file is being downloaded
            Toast.LENGTH_LONG).show();
}