c# - C# 对象初始化器和 ConstructorInfo

Question

任何人都可以为我指出以下解决方案吗？我正在尝试通过使用 CustomAttributeBuilder 复制使用 Object Initializers 的属性属性；

IE。

[Display(Order = 0, Name = "UserNameLabel", ResourceType = typeof(RegistrationDataResources))]

作为..

//Add Display Attribute 
ConstructorInfo displayCtor = typeof(DisplayAttribute).GetConstructor(new Type[] { /* something here? */ });
CustomAttributeBuilder displayAttrib = new CustomAttributeBuilder(displayCtor, new object[] { /*..*/});
propertyBuilder.SetCustomAttribute(displayAttrib);

Answer 1

您似乎需要使用 CustomAttributeBuilder 的构造函数，它允许您指定属性及其值。你试过这个吗？

        ConstructorInfo displayCtor = typeof(TestAttribute).GetConstructor(new Type[] {});
        PropertyInfo conProperty = typeof (TestAttribute).GetProperty("TestProperty");
        CustomAttributeBuilder displayAttrib = new CustomAttributeBuilder(displayCtor, new object[] {}, new[] {conProperty}, new object[] {"Hello"});

上面的代码适用于：

    [Test(TestProperty = "Hello")]

另请注意，在您的示例中，您的属性“ ”与构造函数“ ”Display不匹配DataValidationAttribute

编辑：

完整样本：

using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Threading;

namespace SO5841769
{

    class TestAttribute : Attribute
    {
        public string TestProperty { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            AppDomain myDomain = Thread.GetDomain();
            AssemblyName myAsmName = new AssemblyName();
            myAsmName.Name = "MyDynamicAssembly";
            AssemblyBuilder myAsmBuilder = myDomain.DefineDynamicAssembly(myAsmName, AssemblyBuilderAccess.RunAndSave);
            ModuleBuilder myModBuilder = myAsmBuilder.DefineDynamicModule(myAsmName.Name, myAsmName.Name + ".dll");
            TypeBuilder myTypeBuilder = myModBuilder.DefineType("Data", TypeAttributes.Public);
            FieldBuilder someFieldBuilder = myTypeBuilder.DefineField("someField", typeof(string), FieldAttributes.Private); 
            PropertyBuilder somePropertyBuilder = myTypeBuilder.DefineProperty("SomeProperty", PropertyAttributes.HasDefault, typeof(string), null);
            MethodAttributes getSetAttr = MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.HideBySig;
            ConstructorInfo displayCtor = typeof(TestAttribute).GetConstructor(new Type[] { });
            PropertyInfo conProperty = typeof (TestAttribute).GetProperty("TestProperty");
            CustomAttributeBuilder displayAttrib = new CustomAttributeBuilder(displayCtor, new object[] {}, new[] {conProperty}, new object[] {"Hello"});
            somePropertyBuilder.SetCustomAttribute(displayAttrib);
            MethodBuilder somePropertyGetPropMthdBldr = myTypeBuilder.DefineMethod("get_SomeProperty", getSetAttr, typeof(string), Type.EmptyTypes);
            ILGenerator somePropertyGetIL = somePropertyGetPropMthdBldr.GetILGenerator();
            somePropertyGetIL.Emit(OpCodes.Ldarg_0);
            somePropertyGetIL.Emit(OpCodes.Ldfld, someFieldBuilder);
            somePropertyGetIL.Emit(OpCodes.Ret);
            somePropertyBuilder.SetGetMethod(somePropertyGetPropMthdBldr);
            myTypeBuilder.CreateType();
            myAsmBuilder.Save(myAsmName.Name + ".dll");

        }
    }
}