What is the most efficient way to ask a MethodInfo how many parameters it takes?

Question

What is the most efficient way to ask a MethodInfo if it accepts parameters and, if so, how many?

My current solutions would be: methodInfo.GetParameters().Any() and methodInfo.GetParameters().Count().

Is this the most efficient way?

Since I don't actually need any of the ParameterInfo objects, is there a way to do this without a call to GetParameters()?

Endoscope

Answer 1

The two you listed are for LINQ. Any() returns bool - stating that there is at least one. Count() is used any on IEnumerable<T>.

Length (the property) will be the fastest because GetParameters() returns ParameterInfo[].

It does not appear that MethodInfo have any other way to access the number of parameters other than GetParameters().

Yarkand

Are you familiar with MethodImplAttributes or do you know if they could be used to determine this? – Endoscope

I am not personally. It does not look like it applies. – Yarkand

@smartcaveman: MethodImplAttributes specifies method implementation details. As Daniel correctly assumed, it has nothing to do with the number of method parameters. – Flattie

Answer 2

If efficiency matters why don't you just cache the result in a Dictionary<MethodInfo,int>? That way you only need to use reflection only once.

Marvismarwin

Answer 3

If you want to get the count of parameters of a MethodInfo, then use the below code

int intLength = mi.GetParameters().Length; // where mi is a variable of type MethodInfo

Tynes