.Net Core 你必须知道的source-generators
源生成器是 C# 9 中引入的一项功能，允许在编译过程中动态生成代码。它们直接与 C# 编译器集成(Roslyn)并在编译时运行，分析源代码并根据分析结果生成附加代码。
源生成器提供了一种简化的自动化代码生成方法，无需外部工具或单独的预编译步骤。
通过无缝集成到编译过程中，源生成器可以提高生产力、减少错误并实现更高效的开发工作流程。
如何使用
创建 .NET 控制台应用程序。 此示例使用 .NET 6。将 Program 类替换为以下代码。
namespace ConsoleApp;
partial class Program
{
static void Main(string[] args)
{
<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup>HelloFrom("Generated Code");
}
static partial void HelloFrom(string name);
}接下来，我们将创建一个源生成器项目来实现 partial void HelloFrom 方法对应项。
创建一个以 netstandard2.0 目标框架名字对象为目标的 .NET 类库。 添加以下 NuGet 包
<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup>
然后，创建一个名为 HelloSourceGenerator.cs 的新 C# 文件，该文件指定你自己的源生成器，如下所示：
using Microsoft.CodeAnalysis;namespace SourceGeneratorInCSharp{ public class SourceGenerator : ISourceGenerator {<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup>public void Execute(GeneratorExecutionContext context)<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup>{<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup> // Find the main method<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup> var mainMethod = context.Compilation.GetEntryPoint(context.CancellationToken);<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup> // Build up the source code<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup> string source = $@"// using System;namespace {mainMethod.ContainingNamespace.ToDisplayString()}{{ public static partial class {mainMethod.ContainingType.Name} {{<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup>static partial void HelloFrom(string name) =><ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup> Console.WriteLine($""Generator says: Hi from '{{name}}'""); }}}}";<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup> var typeName = mainMethod.ContainingType.Name;<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup> // Add the source code to the compilation<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup> context.AddSource($"{typeName}.g.cs", source);<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup>}<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup>public void Initialize(GeneratorInitializationContext context)<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup>{<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup> // No initialization required for this one<ItemGroup>
<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" PrivateAssets="all" />
<PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
</ItemGroup>} }}
现在，我们有一个正常运行的生成器，但需要将其引用到控制台应用程序。
新引用不是传统的项目引用，必须手动编辑以包含 OutputItemType 和 ReferenceOutputAssembly 属性。
<ItemGroup>
<ProjectReference Include="..\SourceGeneratorInCSharp\SourceGeneratorInCSharp.csproj"
OutputItemType="Analyzer"
ReferenceOutputAssembly="false" />
</ItemGroup>
现在，运行控制台应用程序时，应会看到生成的代码运行并打印到屏幕。
控制台应用程序本身不实现 HelloFrom 方法，而是在编译过程中从源生成器项目生成的源。
如果使用的是 Visual Studio，则可以看到源生成的文件。
在“解决方案资源管理器”窗口中，展开“依赖项”>“分析器”>“SourceGenerator”>“SourceGenerator.HelloSourceGenerator”，然后双击“Program.g.cs”文件即可看到生成的内容。
https://learn.microsoft.com/zh-cn/dotnet/csharp/roslyn-sdk/source-generators-overview
来源:https://www.cnblogs.com/chenyishi/p/18073694
免责声明：由于采集信息均来自互联网，如果侵犯了您的权益，请联系我们【E-Mail:cb@itdo.tech】 我们会及时删除侵权内容，谢谢合作！
页:
[1]