Create Plugin Project

We first need to create a new WinUI class library in VS.

Write Default Metadata

Five fillable metadata items are provided by default:

• Id: Plugin ID
• Name: Plugin name
• Version: Plugin version
• Priority: Loading order, smaller values load earlier
• Dependencies: Plugin dependencies
• SdkVersion: (Auto) SDK version
• BuiltIn: (Auto) Whether it's a built-in plugin
• DllName: (Auto) DLL file name
• MainPlugin: (Auto) Main plugin type
• EntryPoints: (Auto) Entry points

Metadata items (except Dependencies) are set in plugin.json.

ShadowExample.Plugin.Emoji.csproj

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <TargetFramework>net6.0-windows10.0.19041.0</TargetFramework>
        <TargetPlatformMinVersion>10.0.17763.0</TargetPlatformMinVersion>
        <RootNamespace>ShadowExample.Plugin.Emoji</RootNamespace>
        <RuntimeIdentifiers>win10-x86;win10-x64;win10-arm64</RuntimeIdentifiers>
        <UseWinUI>true</UseWinUI>
        <GeneratePackageOnBuild>false</GeneratePackageOnBuild>
        <NoWarn>MSB3277</NoWarn>
        <!-- Nuget -->
        <PackageId>ShadowExample.Plugin.Emoji</PackageId>
        <PluginName>Emoji Plugin</PluginName>
        <Version>1.0.0.12</Version>
        <!-- PluginMeta -->
    </PropertyGroup>
</Project>

Create a new plugin.json in the root directory.

You can use to get variables from .csproj.

Id must correspond to PackageId.

plugin.json

{
  "Id": "{{ PackageId }}",
  "Name": "{{ PluginName }}",
  "Version": "{{ Version }}"
}

Note

In <PluginMeta>, you can use MSBuild property variables:

• MSBuild Reserved and Well-Known Properties
• Common MSBuild Project Properties

The metadata item Dependencies is used to specify the plugin's dependent plugins, allowing the plugin to load after its dependent plugins.

Unlike regular metadata items, it needs to be set in the <ItemGroup> in .csproj.

It also serves as the project's nuget package.

• Must specify Label="Dependencies"
• Must specify Need="(1.0,2.0)" for required version internally

ShadowExample.Plugin.Emoji.csproj

<ItemGroup Label="Dependencies">
    <PackageReference Include="ShadowExample.Plugin.Hello" Version="1.2.1.2"  Need="(1.0,2.0)"  />
    <PackageReference Include="ShadowExample.Plugin.World" Version="1.3.0.0"  Need="(1.0,2.0)"  />
</ItemGroup>

Plugin Main Class

The plugin main class needs to inherit from the custom plugin base class in the plugin loader.

And must use the [MainPlugin] attribute to specify the plugin main class, which will automatically generate corresponding plugin metadata.

LocalPlugin.cs

// Example plugin main class
namespace ShadowViewer.Plugin.Local;

[MainPlugin]
public partial class LocalPlugin : PluginBase
{
}

TIP

You can directly use LocalPlugin.MetaData to get the plugin's metadata information.

Subsequent Development

Next, you can choose to override the default methods in the plugin base class.

Or:

• Use I18N Internationalization
• Custom WinUI Controls
• Custom Resource Dictionaries
• Custom Resource Files