Xamarin Android R open file error "IsFileInPublicLocation"

Question

In Android 11 trying to download a file and open it with the default application.

The code does work in Android version 9 and 10 and correctly asks user which app they want to open the file with.

I am using xamarin essentials to open the file

var filePath = Path.Combine(FileSystem.AppDataDirectory, $"{result.Replace(" ", "")}.pdf");
using (FileStream linkFile = new FileStream(filePath, FileMode.Create, FileAccess.ReadWrite))
{
    await pdfDoc.CopyToAsync(linkFile);
}
if (File.Exists(filePath))
{
    await Launcher.OpenAsync(new OpenFileRequest
    {
        File = new ReadOnlyFile(filePath)
    });
}

Also getting the exact same error when trying to email the file as well with this code

var file = new ReadOnlyFile(filePath);
var emailAttach = new EmailAttachment(file);
email.Attachments.Add(emailAttach);
await Email.ComposeAsync(email);

The Error

Object reference not set to an instance of an object.


  at Xamarin.Essentials.FileProvider.IsFileInPublicLocation (System.String filename) [0x0000d] in d:\a\1\s\Xamarin.Essentials\Types\FileProvider.android.cs:92 
  at Xamarin.Essentials.Platform.GetShareableFileUri (System.String filename) [0x00000] in d:\a\1\s\Xamarin.Essentials\Platform\Platform.android.cs:105 
  at Xamarin.Essentials.Launcher.PlatformOpenAsync (Xamarin.Essentials.OpenFileRequest request) [0x00000] in d:\a\1\s\Xamarin.Essentials\Launcher\Launcher.android.cs:41 
  at Xamarin.Essentials.Launcher.OpenAsync (Xamarin.Essentials.OpenFileRequest request) [0x00000] in d:\a\1\s\Xamarin.Essentials\Launcher\Launcher.shared.cs:43 
  at AppName.Views.JobDetails.GeneratePDF () [0x0034d] in C:\Users\User\source\repos\AppName\AppName\AppName\Views\JobDetails.xaml.cs:416

I have tried using hardcoded paths to a public directory and other helpers for file paths, all with the same error

string fileDir = @"/storage/emulated/0/Android/data/com.*CompanyName*.*AppName*/files/";

string fileDir = Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData);
(And various other special folders)

string fileDir = FileSystem.CacheDirectory

*Edit

Modified code a little to

var readOnlyFile = new ReadOnlyFile(filePath);
var openFileReq = new OpenFileRequest();
openFileReq.File = readOnlyFile;
await Launcher.OpenAsync(openFileReq);

Error happens on

await Email.ComposeAsync(email);

and

await Launcher.OpenAsync(openFileReq);

Xamarin Android R open file error "IsFileInPublicLocation"

0 Answers