调用方法重载

Question

I read the following code on this microsoft page

Type t = typeof(String);

        MethodInfo substr = t.GetMethod("Substring", 
            new Type[] { typeof(int), typeof(int) });

        Object result = 
            substr.Invoke("Hello, World!", new Object[] { 7, 5 });
        Console.WriteLine("{0} returned \"{1}\".", substr, result);

The problem is that there is not an Invoke(String,Object[]) method in MethodInfo class. (t.GetMethod returns a MethodInfo object right?)

Also another question: sometimes I see Object(class/datatype) variables declared as object and sometimes declared as Object. Is there any difference?

Answer 1

1. The first argument of "invoke" is "instance" of type (t). In this sample, it is a "string," but in another sample, it might be int. It is about your starting point. The signature is "object" because you can pass everything (almost) as "object".

2. They are identical. "object" is C# alias of .NETs "Object" type.