CODEWITHSUNDEEP
c#.netmethodsreflectionproperties
Louis Rhys
Louis Rhys

Reputation: 35637

How to check whether an object has certain method/property?

Using dynamic pattern perhaps? You can call any method/property using the dynamic keyword, right? How to check whether the method exist before calling myDynamicObject.DoStuff(), for example?

Upvotes: 186

Views: 215397

Answers (5)

Alexander
Alexander

Reputation: 1263

To avoid AmbiguousMatchException, I would rather say

objectToCheck.GetType().GetMethods().Count(m => m.Name == method) > 0

Upvotes: 0

esskar
esskar

Reputation: 10940

It is an old question, but I just ran into it. Type.GetMethod(string name) will throw an AmbiguousMatchException if there is more than one method with that name, so we better handle that case

public static bool HasMethod(this object objectToCheck, string methodName)
{
    try
    {
        var type = objectToCheck.GetType();
        return type.GetMethod(methodName) != null;
    }
    catch(AmbiguousMatchException)
    {
        // ambiguous means there is more than one result,
        // which means: a method with that name does exist
        return true;
    }
}

Upvotes: 55

Frederik Gheysels
Frederik Gheysels

Reputation: 56934

Wouldn't it be better to not use any dynamic types for this, and let your class implement an interface. Then, you can check at runtime wether an object implements that interface, and thus, has the expected method (or property).

public interface IMyInterface
{
   void Somemethod();
}


IMyInterface x = anyObject as IMyInterface;
if( x != null )
{
   x.Somemethod();
}

I think this is the only correct way.

The thing you're referring to is duck-typing, which is useful in scenarios where you already know that the object has the method, but the compiler cannot check for that. This is useful in COM interop scenarios for instance. (check this article)

If you want to combine duck-typing with reflection for instance, then I think you're missing the goal of duck-typing.

Upvotes: 23

Julien
Julien

Reputation: 7861

You could write something like that : 

public static bool HasMethod(this object objectToCheck, string methodName)
{
    var type = objectToCheck.GetType();
    return type.GetMethod(methodName) != null;
}

Edit : you can even do an extension method and use it like this

myObject.HasMethod("SomeMethod");

Upvotes: 259

Stecya
Stecya

Reputation: 23266

via Reflection

 var property = object.GetType().GetProperty("YourProperty")
 property.SetValue(object,some_value,null);

Similar is for methods

Upvotes: 108

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