.NET 8单文件发布后反射设置私有属性失败求助

这段代码在.NET 4.6.2、.NET 8的DEBUG模式下运行正常，但发布为单文件后调用SetupKeys时抛出**“Property set method not found”**异常，核心是通过反射给带私有set的静态属性赋值时找不到对应的set方法。

原代码 #

/// <summary>
/// This gets called at startup. The point of this is to prevent us from
/// making everything a const with [General.Yes = "General.Yes"]. Saves a step in
/// development that was getting annoying.
/// </summary>
public static void SetupKeys()
{
    var thisNamespace = typeof( TranslationKeys ).Namespace;
    var thisName = nameof( TranslationKeys );
    var fullNameStart = string.Concat( thisNamespace, ".", thisName, "+" );

    var classes = Assembly.GetExecutingAssembly()
            .GetTypes()
            .Where( t => t.IsClass && t.IsNested && t.FullName != null && t.FullName.StartsWith( fullNameStart ) );

    foreach (var c in classes)
    {
        var className = c.Name;
        var props = c.GetProperties();

        foreach (var p in props)
        {
            var propName = p.Name;
            p.SetValue(null, string.Concat(className, ".", propName), BindingFlags.NonPublic, );
        }
    }
}

/// <summary>
/// Things that we will use all over the place.
/// </summary>
public static class General
{
    public static string Yes { get; private set; } = string.Empty;
}

解决办法 #

1. 修正反射的BindingFlags参数

当前调用SetValue时仅传入BindingFlags.NonPublic，但静态属性需要同时指定BindingFlags.Static，且属性本身是public的，需补充BindingFlags.Public。同时获取属性时也要确保覆盖正确的范围：

public static void SetupKeys()
{
    var thisNamespace = typeof(TranslationKeys).Namespace;
    var thisName = nameof(TranslationKeys);
    var fullNameStart = string.Concat(thisNamespace, ".", thisName, "+");

    // 改用typeof获取程序集，避免单文件环境下执行程序集不一致问题
    var classes = typeof(TranslationKeys).Assembly
            .GetTypes()
            .Where(t => t.IsClass && t.IsNested && t.FullName != null && t.FullName.StartsWith(fullNameStart));

    foreach (var c in classes)
    {
        var className = c.Name;
        // 指定BindingFlags获取public静态属性
        var props = c.GetProperties(BindingFlags.Public | BindingFlags.Static);

        foreach (var p in props)
        {
            var propName = p.Name;
            // 组合正确的BindingFlags：public静态属性 + 非公共set方法
            p.SetValue(null, string.Concat(className, ".", propName), 
                BindingFlags.Public | BindingFlags.Static | BindingFlags.NonPublic, 
                null, null, null);
        }
    }
}

2. 禁用或配置单文件发布的裁剪优化

.NET 6+单文件发布默认启用代码裁剪（Trim），编译器会移除它认为未被直接调用的私有方法（包括属性的私有set）。可以通过两种方式处理：

• 全局禁用裁剪：在项目文件（.csproj）中添加配置，适合调试阶段：

  <PropertyGroup>
    <PublishTrimmed>false</PublishTrimmed>
  </PropertyGroup>
  

• 保留指定类型的私有set方法：使用[DynamicDependency]特性告诉编译器不要裁剪相关方法，适合需要保留裁剪优化的场景：

  using System.Diagnostics.CodeAnalysis;
  
  public static class General
  {
      [DynamicDependency(DynamicallyAccessedMemberTypes.PrivateSetters, typeof(string))]
      public static string Yes { get; private set; } = string.Empty;
  }
  

  如果需要批量处理TranslationKeys下的所有嵌套类属性，也可以在TranslationKeys类上添加特性：

  [DynamicDependency(DynamicallyAccessedMemberTypes.PrivateSetters, typeof(TranslationKeys.General))]
  public static class TranslationKeys
  {
      // 嵌套类定义...
  }
  

内容的提问来源于stack exchange，提问作者FoxScully