问题
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()?
回答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().
回答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.
回答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
来源：https://stackoverflow.com/questions/4949503/what-is-the-most-efficient-way-to-ask-a-methodinfo-how-many-parameters-it-takes