How do I find the return type of a method with Sys

问题:

how do I find out the return type of a method from the MethodBase? I'm using PostSharp and trying to override the CompileTimeValidate(MethodBase method) method to make sure the attribute is applied to a method with the correct signature.

Thanks,

回答1:

MethodBase is used as a base class of MethodInfo which has a property ReturnType.

You could try and cast to an instance of MethodInfo and check that property.

回答2:

MethodBase itself does not have a return type because in addition to normal methods it also is used to represent methods, such as constructors, which have no return type. Instead you need to see if it's an instance of MethodInfo and check that for the ReturnType property.

CompileTimeValidate(MethodBase method) {
  var normalMethod = method as MethodInfo;
  if( normalMethod != null) {
    ValidateReturnType(normalMethod.ReturnType);
  }
}

回答3:

Try something like this. MethodInfo has the property but MethodBase is used for constructors as well, and they do not have a return type.

MethodBase b = this.GetType().GetMethods().First(); 
if(b is MethodInfo)
    MessageBox.Show((b as MethodInfo).ReturnType.Name);

回答4:

Try the MethodInfo.ReturnType property.

To get the return type property, first get the Type. From the Type, get the MethodInfo. From the MethodInfo, get the ReturnType.

It seems like you can't do it with MethodBase...

http://msdn.microsoft.com/en-us/library/system.reflection.methodinfo.returntype.aspx