Folder name must be unique in the entire project

[enricosada]

When multiple folders with the same name ( but different path ) exist in the project, the following error occurs:

The project 'Test.fsproj' could not be opened because opening it would cause a folder to be rendered multiple times in the solution explorer. One such problematic item is 'Second\foo.fs'. To open this project in Visual Studio, first edit the project file and fix the problem.

ref:

• Add support for folder organization fsprojects-archive/zzarchive-VisualFSharpPowerTools#116
• bug on stackoverflow

an example (see )

<ItemGroup>
    <Compile Include="First\Second\File.fs" />
    <Compile Include="Second\File.fs" />
</ItemGroup>

instead this is ok:

<ItemGroup>
    <Compile Include="First\Second\File.fs" />
    <Compile Include="Third\File.fs" />
</ItemGroup>

also invalid:

<ItemGroup>
    <Compile Include="First\First\File.fs" />
</ItemGroup>

i got a pr to fix this behaviour

[enricosada]

btw this check is there to prevent something like this:

<ItemGroup>
    <Compile Include="A\B\File.fs" />
    <Compile Include="C\File.fs" />
    <Compile Include="A\File.fs" />
</ItemGroup>

where folder A is rendered two times, before and after folder C

[SpiegelSoft]

This is happening now in a Xamarin Android project. It's impossible to work with F# here, because of the requirement to have resources with multiple resolutions.

[SpiegelSoft]

Visual Studio 2017, V15.6.7

[SpiegelSoft]

The fix in my case was to put the resource includes above the other files, rather than below. I had copied and pasted a bunch of images into the solution, and the resulting fsproj file looked like this:

<ItemGroup>
    <None Include="Resources\AboutResources.txt" />
    <None Include="Properties\AndroidManifest.xml" />
    <Compile Include="Properties\AssemblyInfo.fs" />
    <Compile Include="MainActivity.fs" />
    <AndroidAsset Include="Assets\AboutAssets.txt" />
    <None Include="GettingStarted.Xamarin" />
    <Content Include="packages.config" />
    <AndroidResource Include="Resources\layout\Main.axml" />
    <AndroidResource Include="Resources\values\Strings.xml" />
    <AndroidResource Include="Resources\mipmap-hdpi\Icon.png" />
    <AndroidResource Include="Resources\mipmap-mdpi\Icon.png" />
    <AndroidResource Include="Resources\mipmap-xhdpi\Icon.png" />
    <AndroidResource Include="Resources\mipmap-xxhdpi\Icon.png" />
    <AndroidResource Include="Resources\mipmap-xxxhdpi\Icon.png" />
  </ItemGroup>

Changing it to this fixed the issue:

<ItemGroup>
    <AndroidResource Include="Resources\layout\Main.axml" />
    <AndroidResource Include="Resources\values\Strings.xml" />
    <AndroidResource Include="Resources\mipmap-hdpi\Icon.png" />
    <AndroidResource Include="Resources\mipmap-mdpi\Icon.png" />
    <AndroidResource Include="Resources\mipmap-xhdpi\Icon.png" />
    <AndroidResource Include="Resources\mipmap-xxhdpi\Icon.png" />
    <AndroidResource Include="Resources\mipmap-xxxhdpi\Icon.png" />
    <None Include="Resources\AboutResources.txt" />
    <None Include="Properties\AndroidManifest.xml" />
    <Compile Include="Properties\AssemblyInfo.fs" />
    <Compile Include="MainActivity.fs" />
    <AndroidAsset Include="Assets\AboutAssets.txt" />
    <None Include="GettingStarted.Xamarin" />
    <Content Include="packages.config" />
  </ItemGroup>

[mfortunat]

Thanks @SpiegelSoft
it worked perfectly also with VS 2015.
(Version 14.25431.01 Update 3)

[SpiegelSoft]

This is not fixed. It needs to be reopened.

[SpiegelSoft]

The fix I posted earlier does not work for my current project.

[SpiegelSoft]

Thanks Philip. What I have found is this. File order is crucial. If you have more than one file, the ordering needs to be as follows:

    <AndroidResource Include="Resources\mipmap-hdpi\File1.png" />
    <AndroidResource Include="Resources\mipmap-hdpi\File2.png" />
    <AndroidResource Include="Resources\mipmap-mdpi\File1.png" />
    <AndroidResource Include="Resources\mipmap-mdpi\File2.png" />
    <AndroidResource Include="Resources\mipmap-xhdpi\File1.png" />
    <AndroidResource Include="Resources\mipmap-xhdpi\File2.png" />
    <AndroidResource Include="Resources\mipmap-xxhdpi\File1.png" />
    <AndroidResource Include="Resources\mipmap-xxhdpi\File2.png" />
    <AndroidResource Include="Resources\mipmap-xxxhdpi\File1.png" />
    <AndroidResource Include="Resources\mipmap-xxxhdpi\File2.png" />

Any deviation from this ordering will reintroduce the problem.

[cartermp]

@SpiegelSoft I don't quite recall how Android Studio lays Android resources out on disk, but I vaguely recall a similar ordering. Do the Android Xamarin tools not order in the manner by default?

[SpiegelSoft]

Not using right click with copy and paste.

[SpiegelSoft]

This is with Visual Studio 2017

[cartermp]

The .NET SDK-style project system fully supports these scenarios:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.2</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <Compile Include="First\First\File.fs" />
    <Compile Include="First\Second\File.fs" />
    <Compile Include="Second\File.fs" />
    <Compile Include="Program.fs" />
  </ItemGroup>

</Project>

We're frozen the legacy project system, so I'll close this. Moving code to the .NET SDK project system will resolve any issues of this nature.