Hi, 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,
views:
204answers:
4
+2
A:
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.
JoshBerke
2010-03-22 18:29:33
+3
A:
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);
}
}
JaredPar
2010-03-22 18:30:09
+1
A:
Try something like this. MethodInfo has the property but MethodBase is used for constructs aswell 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);
Oskar Kjellin
2010-03-22 18:31:19
Minor point...if you're already checking `b is MethodInfo`, then a direct cast `(MethodInfo)b` is slightly preferable to `b as MethodInfo`.
Adam Robinson
2010-03-22 18:33:44
How come? :)...
Oskar Kjellin
2010-03-22 19:16:55
The guideline I follow: Use `as` when receiving a null (for an incompatible type) is acceptable to your code. In this case, since a null is *not* acceptable inside the if, use `(MethodInfo)b` instead. Better yet, avoid the cost of doing the cast twice by using `as` instead of `is` and testing against null.
Bevan
2010-03-24 22:23:44
Thanks a lot for that clearification :)
Oskar Kjellin
2010-03-25 09:51:05
A:
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
Eric Eijkelenboom
2010-03-22 18:33:33