Get method by reflection fails

Question

I have the following method delared by Gl:

public static void Get(int pname, out int @params)

I'm trying to get it using reflection in the following way:

MethodInfo mGetMethod = typeof(Gl).GetMethod("Get",
                                             BindingFlags.Public|BindingFlags.Static,
                                             null, 
                                             new Type[] 
                                             { 
                                                 typeof(Int32), 
                                                 typeof(Int32) 
                                             }, 
                                             null);

But I have no success. Why?

Is it because the out keyword?

are you using .NET 4? If so you can use the dynamic keyword to create a reflected object, then call the method directly. That way you don't need the MethodInfo lookup. Downside is, if you get it wrong, you get a runtime exception — ghostJago, Aug 25 '11 at 17:58

Isaac Overacker · Accepted Answer · 2018-01-24T18:35:26.053

7

Use typeof(Int32).MakeByRefType() for your second parameter. I.e.:

MethodInfo mGetMethod = typeof(Gl).GetMethod("Get", bindingFlags.Public|BindingFlags.Static, null, new Type[] { typeof(Int32), typeof(Int32).MakeByRefType() }, null);

edited Jan 24 '18 at 18:35

answered Aug 25 '11 at 17:43

Isaac Overacker

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Found it: http://stackoverflow.com/questions/2438065/c-reflection-how-can-i-invoke-a-method-with-an-out-parameter – Luca Aug 25 '11 at 17:57

score 1 · Answer 2 · answered Aug 25 '11 at 17:48

1

If you need to specify the specific overload for the method then definitely go with what @Isaac Overacker said. Otherwise just don't specify the parameters:

MethodInfo mGetMethod = typeof(Gl).GetMethod("Get", BindingFlags.Public | BindingFlags.Static);

answered Aug 25 '11 at 17:48

Chris Haas

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score 1 · Answer 3 · answered Aug 25 '11 at 17:58

1

The out keyword passes the parameter by reference, which is probably your problem. You will need to flag it as a reference type since C# allows you to overload methods with a byValue and byReference parameter.

answered Aug 25 '11 at 17:58

kmkemp

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score 0 · Answer 4 · answered Aug 25 '11 at 17:43

0

How about trying something like this instead:

MethodInfo method = this.GetType().GetMethod("Get");
if (method != null)
{
    method.Invoke(this, new object[] { "Arg1", "Arg2", "Arg3" });
}

answered Aug 25 '11 at 17:43

James Johnson

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Get method by reflection fails

4 Answers4