如何从类型转换为通用？ [英] How do I convert from type to generic?

问题描述

HY有

给出的这个类：

public static class FooClass<TFoo>
{
    public static TFoo FooMethod(object source)
    {
        // implementation goes here
    }
}

现在我想创建这个类：

public static class FooClass
{
    public static object FooMethod(object source, Type fooType)
    {
        var classType = typeof (FooClass<>).MakeGenericType(fooType);
        var methodInfo = classType.GetMethod("FooMethod", new[]
        {
            typeof (object)
        });
        // WHAT NOW?!
    }
}

也提到：

also to mention:

• 有 FooMethod 的重载在 FooClass< TFoo> ，但我只是想给访问中提到过载（签名匹配 - 除了paramterNames）


• 的返回类型对象将succifient


• 我不能让 FooMethod 在 FooClass 通用 - 它应该是一个旧式界面，因为它会从反射代码中使用

• there are overloads of FooMethod in FooClass<TFoo>, but i only want to give access to mentioned overload (signature is matching - except paramterNames)
• returnType object would be succifient
• i cannot make FooMethod in FooClass generic - it should be an "oldstyle" interface, as it will be used from reflection-code

推荐答案

是这样的：

public static class Foo
{
    public static object FooMethod(object source, Type fooType)
    {
        return typeof(Foo<>).MakeGenericType(fooType)
            .GetMethod("FooMethod").Invoke(null, new object[] { source });
    }
}

然而 - 这种反思可以在一个紧密的循环慢;如果你正在做这个地段，我会被诱惑扭转依赖，因此通用的代码调用到非通用代码：

however - this reflection can be slow in a tight loop; if you are doing this lots, I would be tempted to reverse the dependency, so the generic code calls into the non-generic code:

public static class Foo<TFoo>
{
    public static TFoo FooMethod(object source)
    {
        return (TFoo)Foo.FooMethod(source, typeof(TFoo));
    }
}

（与在非通用版本的执行）

(with the implementation in the non-generic version)

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