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With Dotnet's Blazor opening up a number of possibilities I wanted to give it a shot working with Web Assembly and ImGui's C++ library (an easy and convent GUI library). There is a DotNet wrapper that allows for the use of native functionality that I can use in NetCore 6.

Part of what needs to be done with the wrapper is that you need to include a precompiled DLL to allow it to render and take advantage of the library. This is where the problem happens...

Issue

I'm unable to add the DLL as a referenced item when doing a compiled run, though it has been added and referenced in the project.

How it was added

<ItemGroup>
   <Content Include="$(ProjectDir)/../deps/cimgui/win-x86/cimgui.dll" CopyToOutputDirectory="PreserveNewest" />
   <Content Include="$(ProjectDir)/../deps/cimgui/osx-universal/cimgui.dylib" CopyToOutputDirectory="PreserveNewest" />
   <Content Include="$(ProjectDir)/../deps/cimgui/linux-x64/cimgui.so" CopyToOutputDirectory="PreserveNewest" />
</ItemGroup>
<ItemGroup>
   <Reference Include="cimgui">
      <HintPath>../deps/cimgui/win-x64/cimgui.dll</HintPath>
   </Reference>
</ItemGroup>

Error on Console

blazor.webassembly.js:1 crit: Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
      Unhandled exception rendering component: cimgui
System.DllNotFoundException: cimgui
   at ImGuiNET.ImGui.Text(String fmt)
   at Hadur.Frontend.Pages.Index.StartUp() in C:\Projects\Hadur\frontend\Hadur.Frontend\Pages\Index.razor:line 20
   at Hadur.Frontend.Pages.Index.OnInitializedAsync() in C:\Projects\Hadur\frontend\Hadur.Frontend\Pages\Index.razor:line 28
   at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync()

So looking in I found that seemingly Blazor isnt adding the referenced dll this to the proper folder when doing a debug or publish. I looked under \bin\Debug\net6.0\ and saw the cimgui.dll was added but there is also a wwwroot/_framework where the dll is missing which makes me wonder why this isnt working and if this is a bug in Blazor.

I also saw that in blazor.boot.json the dll doesnt seem to be referenced either and I dont know if this is an issue or not.

Indraneel Dey
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    You're not going to be able to load arbitrary unmanaged Windows dlls into a browser. That's not a capability of Blazor. You're probably going to have to reassess your dependency on this library. – Kirk Woll Mar 21 '22 at 22:10
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    Probably just a dup of https://stackoverflow.com/questions/66966926/c-dll-in-blazor-project – Kirk Woll Mar 21 '22 at 22:15
  • Did you [install the wasm-tools](https://devblogs.microsoft.com/dotnet/asp-net-core-updates-in-net-6-rc-2/#native-dependencies-support-for-blazor-webassembly-apps)? – Crowcoder Mar 21 '22 at 23:14

0 Answers0