CODEWITHSUNDEEP
c#reflection
Zzz
Zzz

Reputation: 3025

MethodInfo.Invoke throws exception for variable number of arguments

My code is attempting to call multiple methods with a variable number of arguments using MethodInfo.Invoke but the call throws an ArgumentException. What is causing this and how can I fix it?

The methods signature of the methods being called looks like this:

private static string MethodBeingCalled(params string[] args) 
{
    //do stuff
    return stringToReturn;
}

The line of code that is calling these methods looks like this:

string valueReturned = method.Invoke(obj, new object[] { "01" }).ToString();

This line throws an ArgumentException: 

Object of type 'System.String' cannot be converted to type 'System.String[]'.

When I change MethodBeingCalled to take a fixed list of arguments(ie: MethodBeingCalled(string arg)) everything works fine.

Upvotes: 2

Views: 1218

Answers (2)

Ananthan Unni
Ananthan Unni

Reputation: 1304

See this answer here . It checks for ParamArrayAttribute present and passes values as array.

Upvotes: 1

gretro
gretro

Reputation: 2009

params is actually a workaround of the compiler. Behind, the real type of the parameter is an array. So when you do this : method.Invoke(obj, new object[] { "01" }), that cannot work. You need to do this :

method.Invoke(obj, new object[] { new string[] {"01"} })

That should work.

Upvotes: 4

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