ShadowPluginLoader.WinUI

Create an SDK Project ​

Start with a class library that both your app and its plugins can reference. We'll call it the SDK. It will hold plugin metadata, the plugin base class, and any app features you want to make available to plugins.

Create the library ​

In Visual Studio, create a WinUI class library named ShadowExample.Core. Open its project file and use this configuration as a starting point:

ShadowExample.Core.csproj
xml
<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0-windows10.0.19041.0</TargetFramework>
    <TargetPlatformMinVersion>10.0.19041.0</TargetPlatformMinVersion>
    <RootNamespace>ShadowExample.Core</RootNamespace>
    <RuntimeIdentifiers>win-x86;win-x64;win-arm64</RuntimeIdentifiers>
    <UseWinUI>true</UseWinUI>
    <Nullable>enable</Nullable>
    <LangVersion>preview</LangVersion>
    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
    <PackageId>ShadowExample.Core</PackageId>
    <Version>1.3.1</Version>
    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
    <PackageOutputPath>../NugetPackages</PackageOutputPath>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="ShadowPluginLoader.WinUI" Version="3.1.9" />
  </ItemGroup>
</Project>

Two settings are useful here. CopyLocalLockFileAssemblies copies dependencies to the output directory so the tool can read your metadata. GeneratePackageOnBuild creates a NuGet package that the app and plugins can reference.

The example SDK version is 1.3.1. You can choose your own version; just use the same one when referencing the SDK later.

Mark it as an SDK project ​

Create Tools.Config.props in the project directory and set IsPluginLoader to true:

Tools.Config.props
xml
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <IsPluginLoader>true</IsPluginLoader>
    <IsPlugin>false</IsPlugin>
    <AutoPluginPackage>false</AutoPluginPackage>
    <AutoGenerateI18N>true</AutoGenerateI18N>
  </PropertyGroup>
</Project>

This tells the build tool to generate plugin.d.json, which describes the information plugins can provide. The file is included in the SDK's NuGet package for plugin projects to use.

Next, define your plugin metadata, base class, and loader. Once those are ready, build the SDK.

See Tools.Config.props for the other settings.