Download and Save PDF for viewing

Question

Im trying to download a PDF document from my app and display it in IBooks or at least make it available to read some how when its completed downloading.

I followed the download example from Xamarin which allows me download the PDF and save it locally. Its being save in the wrong encoding also.

This is what I've tried so far.

private void PdfClickHandler()
{
    var webClient = new WebClient();

    webClient.DownloadStringCompleted += (s, e) => {
        var text = e.Result; // get the downloaded text
        string documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
        string localFilename = $"{_blueways}.pdf";
        // writes to local storage
        File.WriteAllText(Path.Combine(documentsPath, localFilename), text); 

        InvokeOnMainThread(() => {
            new UIAlertView("Done", "File downloaded and saved", null, "OK", null).Show();
        });
    };

    var url = new Uri(_blueway.PDF);
    webClient.Encoding = Encoding.UTF8;
    webClient.DownloadStringAsync(url);
}

Solution 1

Do not use DownloadStringAsync for "binary" data, use DownloadDataAsync:

Downloads the resource as a Byte array from the URI specified as an asynchronous operation.

private void PdfClickHandler ()
{
    var webClient = new WebClient ();

    webClient.DownloadDataCompleted += (s, e) => {
        var data = e.Result;
        string documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
        string localFilename = $"{_blueways}.pdf";
        File.WriteAllBytes (Path.Combine (documentsPath, localFilename), data);
        InvokeOnMainThread (() => {
            new UIAlertView ("Done", "File downloaded and saved", null, "OK", null).Show ();
        });
    };
    var url = new Uri ("_blueway.PDF");
    webClient.DownloadDataAsync (url);
}

Solution 2

// Retrieving the URL
var pdfUrl = new Uri("url.pdf"); //enter your PDF path here

// Open PDF URL with device browser to download
Device.OpenUri(pdfUrl);

Comments

[poupou]

Unless you know the size of the file you're downloading (and that it is small) you better download it into a file (or risk running out of memory).

[dharam]

I tried the same no error nothing but, file isn't saving.

[Jonty Morris]

Doesn't work on the majority of Android devices... The whole purpose of downloading the PDF locally is to skip this problem