.NET Core 3.0 embedded resources weren't compiled into executable

[hez2010]

• .NET Core Version: 3.0 preview 8
• Windows version: 1903 (18362.295)
• Does the bug reproduce also in WPF for .NET Framework 4.8?: No

Problem description:
Embedded resources weren't compiled into executable.
I added an image to a resx file Resource1.resx, and add the resource file to project file:

  <ItemGroup>
    <Compile Update="Resources\Resource1.Designer.cs">
      <DesignTime>True</DesignTime>
      <AutoGen>True</AutoGen>
      <DependentUpon>Resource1.resx</DependentUpon>
    </Compile>
  </ItemGroup>

  <ItemGroup>
    <EmbeddedResource Update="Resources\Resource1.resx">
      <Generator>ResXFileCodeGenerator</Generator>
      <LastGenOutput>Resource1.Designer.cs</LastGenOutput>
    </EmbeddedResource>
  </ItemGroup>

Then I use this image in WPF <Image Source="..." />

Actual behavior:
The image should display in my WPF app.

Expected behavior:
The image can only display in Visual Studio XAML Designer.

Minimal repro:

WpfTest.zip

Update
Not only WPF projects, all kinds of projects in .NET Core 3.0 cannot correctly use resource files.

[vatsan-madhavan]

@rainersigwald do you have any ideas what’s going on?

[rainersigwald]

Using the repro project, I also don't see an image when running the application, but I do see a byte-array resource embedded:

That matches what I'd expect from the resx:

  <data name="_592e202b3f70f28bd23fd9f830a8fb0a" type="System.Resources.ResXFileRef, System.Windows.Forms">
    <value>592e202b3f70f28bd23fd9f830a8fb0a.jpg;System.Byte[], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
  </data>

@vatsan-madhavan, can you take the next step? I don't know what

<Image Source="/Resources/592e202b3f70f28bd23fd9f830a8fb0a.jpg"></Image>

boils down to in terms of interacting with the embedded resources.

[rainersigwald]

Not only WPF projects, all kinds of projects in .NET Core 3.0 cannot correctly use resource files.

@hez2010, can you elaborate on this, please? The embedding process changed a lot in 3.0 but we're not aware of any specific problems. What else have you found not to work?

[hez2010]

@rainersigwald
You can add some resx files into your project, and then run with Release configuration

dotnet run -c Release

Then you will find all resources becomes null.

A repro sample:
ResourceFiles.zip

However, I think this issue is different from the wpf issue I mentioned in the top post because using resources in wpf xaml doesn't require a resx file.
See this new repro:
WpfTestNew.zip

[weltkante]

@hez2010 your original post repros also on Desktop Framework if you reconstruct what you specify in the .NET Core project, so its not a runtime/build failure, but probably misconfiguration due to bad defaults. It works in the designer because it looks in the file system of the project. Note that WPF doesn't use resx resources, you should use the WPF-style resource embedding. (<Resource> tag instead of <EmbeddedResource> and no resx file, just adding the image as a resource). It may look like it works in Desktop Framework by default if you included the image itself in the project, but then you weren't referencing the resx.

As far as the second example is concerned, I don't know if Core WPF is globally including all image extensions under the Resource build action; Desktop Framework doesn't auto include files, but when you manually included the file it would automatically set the build action to Resource for image file extensions when you are in a WPF project. If the resource globbing is inherited from base Core project behavior the build action may be wrong (you can see it in VS when you select the file properties from the context menu of the solution explorer). Can't test right now since I'm not at my VS 2019 machine. If its None then that explains why its not working.

In this case the fix is for WPF SDK to either turn off globbing of images and similar resources (so you have to add them manually under the right build action like Desktop, ideally having the same defaults in the project system to get the same experience) or replicate the default build actions of the Desktop Framework WPF project system in the automatically included files. Automatically including files as None where Desktop project system has a different default is too confusing.

[hez2010]

As for the issue I mentioned in my original post, after changing build option of my images to Resource, it works as expected.

As for the second issue Not only WPF projects, all kinds of projects in .NET Core 3.0 cannot correctly use resource files, I have opened another issue, see https://github.com/dotnet/roslyn/issues/38437

[vatsan-madhavan]

See related issue/discussion at dotnet/project-system#4534

[vatsan-madhavan]

@hez2010 let's know if we can close out this issue now since you seem to have a path forward.

[hez2010]

Yes, this issue can be closed because it was caused by dotnet/project-system#4534, not WPF itself.