Avalonia.Markup.Xaml.XamlLoadException: "No precompiled XAML found for

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FoggyFinder

I've created a brand new project from Avalonia template but when I run it I got exception:

> Avalonia.Markup.Xaml.XamlLoadException: "No precompiled XAML found for AvaloniaApplication2.App, make sure to specify x:Class and include your XAML file as AvaloniaResource"

How is it possible ?

Top Answer

FoggyFinder

Another option that worth to try:

1. Rename all `.axaml` files to `.xaml`:

For example, `App.axaml` -> `App.xaml`; `App.axaml.cs` -> `App.xaml.cs`

2. Add these lines to `.csproj` file:

```xml
<ItemGroup>
  <EmbeddedResource Include="**\*.xaml">
    <SubType>Designer</SubType>
  </EmbeddedResource>
</ItemGroup>
```

3. Make sure `.csproj` doesn't contain anything that looks like

```xml
<ItemGroup>
  <EmbeddedResource Remove="App.xaml" />
</ItemGroup>
```

or

```xml
<ItemGroup>
  <None Update="App.xaml">
    <Generator>MSBuild:Compile</Generator>
  </None>
</ItemGroup>
```

For simplest project `.csproj` file should be like one below:

```xml
<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <EmbeddedResource Include="**\*.xaml">
      <SubType>Designer</SubType>
    </EmbeddedResource>
  </ItemGroup>
  <ItemGroup>
    <PackageReference Include="Avalonia" Version="0.9.11" />
    <PackageReference Include="Avalonia.Desktop" Version="0.9.11" />
  </ItemGroup>
</Project>
```

Be aware: 

*`VS` breaks your `.csproj` every time you add new `Window.xaml` or `UserControl.xaml` so you have to adjust project file manually.*

Answer #2

FoggyFinder

Sadly, but this is a well known issue. For details see: 

[Avalonia.Markup.Xaml.XamlLoadException after creating project #4456](https://github.com/AvaloniaUI/Avalonia/issues/4456)

[Avalonia.Markup.Xaml.XamlLoadException #4426](https://github.com/AvaloniaUI/Avalonia/issues/4426)

[Visual Studio Template Problem #4373](https://github.com/AvaloniaUI/Avalonia/issues/4373)

Until the bug is fixed you can try next steps:

1. Update to latest version.

Usually this means the new minor version of package was released. 

For example, `csproj` file after creation looks like

```xml
  <ItemGroup>
    <PackageReference Include="Avalonia" Version="0.9.11" />
    <PackageReference Include="Avalonia.Desktop" Version="0.9.11" />
  </ItemGroup>
```

but latest package is `0.9.12` already:

```xml
  <ItemGroup>
    <PackageReference Include="Avalonia" Version="0.9.12" />
    <PackageReference Include="Avalonia.Desktop" Version="0.9.12" />
  </ItemGroup>
```

2. Close VS and remove "`.bin`"/"`.obj`" folders.

3. Reopen VS.

4. Build & Run

No guarantee that these steps will be enough but, at least, it works for me.

2 Answers