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[UPDATED] How to call the method from the base of the base of the current class ? (base.base.MyMethod) - Jonathan ANTOINE

Jonathan ANTOINE — Fri, 13 May 2011 10:25:44 +0200

Thank you for your comment and it works like a charm !

Btw, there is still reflection in your solution, the only difference is that we use 'this' as the current instance without recreating one.

I will update my post to add your solution

Thx a lot !

[UPDATED] How to call the method from the base of the base of the current class ? (base.base.MyMethod) - Thomas Levesque

Thomas Levesque — Fri, 13 May 2011 00:31:53 +0200

Interesting...
.
Normally, you should never need to call base.base.SomeMethod, it's usually a sign of a bad design because you're not supposed to be aware of implementation details of the base class. But of course in the case of the TabControl you're not in control of the base classes, so it's different...
.
Anyway, I don't really like this solution... Two main reasons :
- you have to create a dummy instance of the class, which is pretty bad for performance and could have unexpected side effects
- it uses reflection (also bad for performance) on a non documented private field of the Delegate class. The implementation of this class could change in future versions, and this solution wouldn't work any more.
.
What you need to achieve this is a non-virtual call to GrandFather.MyMethod. This can be done by generating code at runtime with DynamicMethod:

   class Child : Father
   {
       private delegate void MyMethodOpenDelegate(GrandFather instance, object param);
       private static readonly MyMethodOpenDelegate _grandFather_MyMethod;
       
       static Child()
       {
           DynamicMethod dm = new DynamicMethod(
               "grandFather_MyMethod",
               typeof(void),
               new Type[] {typeof(GrandFather), typeof(object)},
               typeof(Child));
           
           var il = dm.GetILGenerator();
           il.Emit(OpCodes.Ldarg_0);
           il.Emit(OpCodes.Ldarg_1);
           il.EmitCall(OpCodes.Call, typeof(GrandFather).GetMethod("MyMethod"), null);
           il.Emit(OpCodes.Ret);
           _grandFather_MyMethod =
               (MyMethodOpenDelegate)dm.CreateDelegate(
                   typeof(MyMethodOpenDelegate));
       }
       
       public override void MyMethod(object param)
       {
           _grandFather_MyMethod(this, param);
       }
   }

(note the use of OpCodes.Call instead of OpCodes.Callvirt)

[ping] [UPDATED] How to call the method from the base of the base of the current class ? (base.base.MyMethod) - DotNetKicks.com

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[ping] [UPDATED] How to call the method from the base of the base of the current class ? (base.base.MyMethod) - DotNetShoutout

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