如何在C＃中使用泛型动态对象 [英] How to use dynamic object with generics in C#

问题描述

我创建了一个动态对象。我需要将此作为泛型类型传递给方法。我怎么能达到同样的目的？



例如：



说我有动态对象obj，我必须获取此对象的类型并将其传递给期望泛型的方法。



类型type = obj.GetType（）;



示例 - ClassA< t> class = new ClassA< t>（）;



我尝试过：



我试图将类型为动态对象obj的类型变量传递给ClassA< t> class = new ClassA< t>（）;但这不起作用。

任何想法如何处理这种情况？

Hi,

I have a dynamic object created. I need to pass this as a generic type to a method. How would I able to achieve the same ?

Example :

Say I'm having an dynamic object obj, I have to fetch the type of this object and pass it to the method which expects a generic.

Type type = obj.GetType();

example - ClassA<t> class = new ClassA<t>();

What I have tried:

I have tried to pass type variable which has type of dynamic object obj to the ClassA<t> class = new ClassA<t>(); but this doesn't work.
Any idea how to handle this scenario ?

推荐答案

你将无法直接创建一个类的强类型实例，因为编译器没有足够的信息来知道封闭的泛型类型是什么。



您可以创建一个后期绑定的实例使用反射的类型：

You won't be able to directly create a strongly-typed instance of the class, as the compiler doesn't have enough information to know what the closed generic type is.

You can create a late-bound instance of the type using reflection:

Type t = obj.GetType();
Type myType = typeof(ClassA<>).MakeGenericType(t);
object instance = Activator.CreateInstance(myType);

或者您可以使用反射来调用创建和使用实例的通用方法：

Or you can use reflection to call a generic method to create and use the instance:

static class Helper
{
    private static readonly MethodInfo DoStuffMethod = typeof(Helper).GetMethod("DoStuffHelper", BindingFlags.NonPublic | BindingFlags.Static);
    
    private static void DoStuffHelper<T>(T value)
    {
        var instance = new ClassA<T>();
        ...
    }
    
    public static void DoStuff(object value)
    {
        if (value == null) throw new ArgumentNullException(nameof(value));
        
        Type t = value.GetType();
        MethodInfo m = DoStuffMethod.MakeGenericMethod(t);
        m.Invoke(null, new[] { value });
    }
}

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