[iOS][Maui.Essentials] File.ContentType from MediaPicker is not in MIME format

[takla21]

Description

Unlike other platforms, ContentType property from the file received after calling MediaPicker.PickPhotoAsync is not in the MIME format.

Actual result

Expected result

Steps to Reproduce

• Deploy sample on iOS
• Click on the button (to open image gallery)
• Pick any picture

Link to public reproduction project repository

https://github.com/takla21/MauiEssentialsContentTypeSample

Version with bug

7.0.86

Last version that worked well

Unknown/Other

Affected platforms

iOS

Affected platform versions

iOS 16.4

Did you find any workaround?

No response

Relevant log output

No response

[ghost]

We've added this issue to our backlog, and we will work to address it as time and resources allow. If you have any additional information or questions about this issue, please leave a comment. For additional info about issue management, please read our Triage Process.

[XamlTest]

Verified this on Visual Studio Enterprise 17.9.0 Preview 1(8.0.3). Repro on iOS 17.0, not repro on Windows 11 and Android 14.0-API34 with below Project: MediaPickerContentType.zip

[breyed]

The summary for FileBase.ContentType is:

Gets or sets the file's content type as a MIME type (e.g.: image/png).

PickPhotoAsync on iOS is failing to include the image/ prefix. If you pick a photo, ContentType is jpeg instead of image/jpeg. If you pick a screenshot, ContentType is png instead of image/png.

[dotMorten]

I'm hitting this too and took a while to figure out why this wasn't working right (also I don't get why MediaPicker.CapturePhotoAsync is returning a PNG in the first place with no way of getting at the original UIImage. That seem very inefficient for photos.

Anyway the bug is most obviously here: https://github.com/dotnet/maui/blob/372c66ce0107599fe2b9f804492d91e3f99a3d1b/src/Essentials/src/FileSystem/FileSystem.ios.tvos.watchos.macos.cs#L65-L74 It just uses the extension, which isn't a content type. A quick localized fix would be to use the overload that sets the contenttype here: https://github.com/dotnet/maui/blob/372c66ce0107599fe2b9f804492d91e3f99a3d1b/src/Essentials/src/FileSystem/FileSystem.ios.cs#L186

[FlavioGoncalves-Cayas]

Same thing for capturing/picking videos.

[MitchBomcanhao]

I'm hitting this too and took a while to figure out why this wasn't working right (also I don't get why MediaPicker.CapturePhotoAsync is returning a PNG in the first place with no way of getting at the original UIImage. That seem very inefficient for photos.

Anyway the bug is most obviously here:

maui/src/Essentials/src/FileSystem/FileSystem.ios.tvos.watchos.macos.cs

Lines 65 to 74 in 372c66c

string PlatformGetContentType(string extension) { // ios does not like the extensions extension = extension?.TrimStart('.');

// var id = UTType.CreatePreferredIdentifier(UTType.TagClassFilenameExtension, extension, null); // var mimeTypes = UTType.CopyAllTags(id, UniformTypeIdentifiers.UTTagClass.MimeType.ToString()); // return mimeTypes?.Length > 0 ? mimeTypes[0] : null;

return extension;

It just uses the extension, which isn't a content type. A quick localized fix would be to use the overload that sets the contenttype here: maui/src/Essentials/src/FileSystem/FileSystem.ios.cs

Line 186 in 372c66c

: base()

the PR says that the developer was "still working on it" over 2 years ago. guess they forgot. Pull request comment https://github.com/dotnet/maui/pull/4272/files#r806907016

[FlavioGoncalves-Cayas]

And then the PR just got merged anyways, I guess... @rmarinho @mattleibow