Invoke an overloaded generic method on a static class

问题

I'm trying to invoke methods on the InputExtensions static class in order to create overloads for the methods on the HtmlHelper class.

So anyway, I still couldn't invoke the methods of the InputExtensions class. Here's part of the code that I'm using to do so:

    Type inputExtensions = typeof(InputExtensions);
    MethodInfo methodInfo = null;
    MethodInfo genericMethod = null;
    switch (propertyViewingMode.ViewingLevel)
    {
        case 1:
            methodInfo = inputExtensions.GetMethod(methodName, new Type[] { typeof(HtmlHelper<TModel>), typeof(Expression<Func<TModel, TProperty>>), typeof(Object) });
            genericMethod = methodInfo.MakeGenericMethod(typeof(TModel), typeof(TProperty));
            result = genericMethod.Invoke(null, new object[] { helper, expression, new { @class = "readOnly", @readonly = "read-only" } }) as MvcHtmlString;
            break;
        case 2:
            methodInfo = inputExtensions.GetMethod(methodName, new Type[] { typeof(HtmlHelper<TModel>), typeof(Expression<Func<TModel, TProperty>>) });
            genericMethod = methodInfo.MakeGenericMethod(typeof(TModel), typeof(TProperty));
            result = genericMethod.Invoke(null, new object[] { helper, expression }) as MvcHtmlString;
            break;
        default:
            result = new MvcHtmlString(String.Empty);
            break;
    }

The problem is that methodInfo is always null, which means that Type.GetMethod is not finding the method I'm trying to invoke.

UPDATE: Note that when I do not provide the GetMethod method with a Type[] array, it throws an exception telling me that the call is ambiguous.

UPDATE 2: This is the method I'm trying to invoke:

TextBoxFor<TModel, TProperty>(HtmlHelper<TModel>, Expression<Func<TModel, TProperty>>, Object)

ANSWER:

    Type inputExtensions = typeof(InputExtensions);
    IEnumerable<MethodInfo> methods = null;
    MethodInfo genericMethod = null;
    MethodInfo methodInfo = null;
    switch (propertyViewingMode.ViewingLevel)
    {
        case 1:
            methods = inputExtensions.GetMethods().Where(m => m.IsGenericMethod && m.Name.Equals(methodName))
                                                        .Where(x => x.GetParameters().Count() == 3);
            methodInfo = methods.FirstOrDefault(x => x.GetParameters()[2].ParameterType.FullName == "System.Object");
            if (methodInfo != null)
            {
                genericMethod = methodInfo.MakeGenericMethod(new[] { typeof(TModel), typeof(TProperty) });
                result = genericMethod.Invoke(null, new object[] { helper, expression, new { @class = "readOnly", @readonly = "read-only" } }) as MvcHtmlString;
            }
            break;
        case 2:
            methods = inputExtensions.GetMethods().Where(m => m.IsGenericMethod && m.Name.Equals(methodName))
                                                        .Where(x => x.GetParameters().Count() == 2);
            methodInfo = methods.FirstOrDefault();
            if (methodInfo != null)
            {
                genericMethod = methodInfo.MakeGenericMethod(new[] { typeof(TModel), typeof(TProperty) });
                result = genericMethod.Invoke(null, new object[] { helper, expression }) as MvcHtmlString;
            }
            break;
        default:
            result = new MvcHtmlString(String.Empty);
            break;
    }

回答1:

I believe you want:

BindingFlags.Public | BindingFlags.Static

Edit:

Try iterating over the methods in debug mode until you find the one you're looking for, then you can examine the params to make sure they all line up.

typeof(A).GetMethods().Where(m => m.IsGenericMethod); 

回答2:

Unfortunately, it seems that it is not possible... http://blogs.msdn.com/b/yirutang/archive/2005/09/14/466280.aspx

The only thing you can do is to iterate over all methods with given name and analyze argument types by yourself :(

来源：https://stackoverflow.com/questions/10634988/invoke-an-overloaded-generic-method-on-a-static-class