C# make generic method that knows how to call function on "some" class

Question

is it possible to make generic function in c# that get as input some class and method (of the class) and parameters to the method ( and maybe the result type ) and make instance of that class and call to the function of the class with the parameters and return the result?

See here: http://msdn.microsoft.com/library/system.type.getconstructor%28v=vs.110%29.aspx and http://msdn.microsoft.com/library/system.type.getconstructor%28v=vs.110%29.aspx — Flat Eric, Jun 06 '14 at 13:23
When you say "get as input... method", do you mean a string containing the method name? — Ben Aaronson, Jun 06 '14 at 13:28

score 4 · Accepted Answer · answered Jun 06 '14 at 13:25

Sure.

public class MyClass
{
    public class Test
    {
        public int TestMethod(int a, int b)
        {
            return a + b;
        }
    }

    public static void Main()
    {
        int result = ExecuteMethod<Test, int>("TestMethod", 1, 2);
        Console.Read();
    }

    public static TResult ExecuteMethod<TClass, TResult>(string methodName, params object[] parameters)
    {
        // Instantiate the class (requires a default parameterless constructor for the TClass type)
        var instance = Activator.CreateInstance<TClass>();

        // Gets method to execute
        var method = typeof(TClass).GetMethod(methodName, BindingFlags.Public | BindingFlags.Instance);

        // Executes and returns result
        return (TResult)method.Invoke(instance, parameters);
    }
}

score 2 · Answer 2 · answered Jun 06 '14 at 13:25

Unless Reflection is your absolute option, use one of the following delegates:

Action<T>: Will let you execute a method that does not return a value. There are several overloads that will let you pass in additional arguments.
Func<TResult>: Will let you execute a method that returns a result of type TResult. There are more overloads that will let you pass in additional arguments. They all follow the syntax Func<T1, T2, T3, TResult> and so on.
And finally, you can define your own delegate.

score 1 · Answer 3 · edited May 23 '17 at 12:06

1

Yes it's possible. You can do that with reflection.

Here you have a few useful links

Create an instance with reflection

How to invoke method with parameters

edited May 23 '17 at 12:06

Community

1
1

answered Jun 06 '14 at 13:22

vfabre

1,388
12
23

score 1 · Answer 4 · answered Jun 06 '14 at 13:31

Here's how you create an instance of a class using reflection and then call a method on that class.

Assuming you have a class:

public class MyType
{
    public void DoSomething()
    {
        // do stuff here
    }
}

You could do the following:

Type instanceType = Type.GetType("MyType");
object instance = Activator.CreateInstance(instanceType);

MethodInfo method = instanceType.GetMethod("MethodName");
object returnValue = method.Invoke(instance, new object[] { /* paramaters go here */ });

C# make generic method that knows how to call function on "some" class

4 Answers4