如何把匿名类型.GetType()返回的对象传进泛型里面

//怎么取得匿名类型的Type放到

//泛型T当中？？



var 匿名 = new {

 A = 0,

 B = 1 };

Type t = 匿名.GetType();



//然后下面

var xx = dbContext.Database.SqlQuery<t>("sql");

//就悲剧了



var xx2 = dbContext.Database.SqlQuery<dynamic>("sql");

//xx2有列表,但是都是Object..~~~无法显示真实项,用Profile跟..SQL确实提交了.

求解释

msdn大神的解决办法

看到了所以记录下来

出现那个问题的原因是动态类型上没有 Entity Framework 需要的属性定义，Entity Framework 是通过反射类型上的属性来做映射的。为了解决这个问题，我用到了 Emit 技术，动态产生一个类型，并且动态写入 IL 代码产生属性。



代码如下，测试在 C# 4.0 上通过。

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Data.Entity;

using System.Collections;

using System.Reflection.Emit;

using System.Reflection;

 

namespace Demo

{

  public class Program

  {

    public static void Main(string[] args)

    {

      string connectionString = "Server=(local); Integrated Security=true; Database=master";

      using (DbContext context = new DbContext(connectionString))

      {

        TypeBuilder builder = Program.CreateTypeBuilder("MyDynamicAssembly", "MyModule", "MyType");

        Program.CreateAutoImplementedProperty(builder, "name", typeof(string));

        Program.CreateAutoImplementedProperty(builder, "type", typeof(string));

        Program.CreateAutoImplementedProperty(builder, "id", typeof(int));

 

        Type resultType = builder.CreateType();

 

        dynamic queryResult = context.Database.SqlQuery(resultType, "SELECT * FROM sys.sysobjects");

 

        Console.WriteLine("{0,20} {1,4} {2,10}", "Name", "Type", "ID");

        foreach (dynamic item in queryResult)

        {

          Console.WriteLine("{0,10} {1,4} {2,10}", item.name, item.type, item.id);

        }

      }

 

      Console.ReadKey();

    }

 

    public static TypeBuilder CreateTypeBuilder(string assemblyName, string moduleName, string typeName)

    {

      TypeBuilder typeBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(new AssemblyName(assemblyName), AssemblyBuilderAccess.Run).DefineDynamicModule(moduleName).DefineType(typeName, TypeAttributes.Public);

      typeBuilder.DefineDefaultConstructor(MethodAttributes.Public);

      return typeBuilder;

    }

 

    public static void CreateAutoImplementedProperty(TypeBuilder builder, string propertyName, Type propertyType)

    {

      const string PrivateFieldPrefix = "m_";

      const string GetterPrefix = "get_";

      const string SetterPrefix = "set_";

 

      // Generate the field.

      FieldBuilder fieldBuilder = builder.DefineField(string.Concat(PrivateFieldPrefix, propertyName), propertyType, FieldAttributes.Private);

 

      // Generate the property

      PropertyBuilder propertyBuilder = builder.DefineProperty(propertyName, PropertyAttributes.HasDefault, propertyType, null);

 

      // Property getter and setter attributes.

      MethodAttributes propertyMethodAttributes = MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.HideBySig;

 

      // Define the getter method.

      MethodBuilder getterMethod = builder.DefineMethod(string.Concat(GetterPrefix, propertyName), propertyMethodAttributes, propertyType, Type.EmptyTypes);

 

      // Emit the IL code.

      // ldarg.0

      // ldfld,_field

      // ret

      ILGenerator getterILCode = getterMethod.GetILGenerator();

      getterILCode.Emit(OpCodes.Ldarg_0);

      getterILCode.Emit(OpCodes.Ldfld, fieldBuilder);

      getterILCode.Emit(OpCodes.Ret);

 

      // Define the setter method.

      MethodBuilder setterMethod = builder.DefineMethod(string.Concat(SetterPrefix, propertyName), propertyMethodAttributes, null, new Type[] { propertyType });

 

      // Emit the IL code.

      // ldarg.0

      // ldarg.1

      // stfld,_field

      // ret

      ILGenerator setterILCode = setterMethod.GetILGenerator();

      setterILCode.Emit(OpCodes.Ldarg_0);

      setterILCode.Emit(OpCodes.Ldarg_1);

      setterILCode.Emit(OpCodes.Stfld, fieldBuilder);

      setterILCode.Emit(OpCodes.Ret);

 

      propertyBuilder.SetGetMethod(getterMethod);

      propertyBuilder.SetSetMethod(setterMethod);

    }

  }

}

转自：http://www.cnblogs.com/0banana0/archive/2012/05/05/2484698.html

注：这样应该可以轻松实现 DataTable To Class