Question

.Net 3.5, using C#

I have an instance of a class (A) that has been called via a virtual method from a derived class (B). Within the method (a method of class A) I have discovered the Type of class B that has made the call, and using reflection I have examined class B and discovered a property whose value I want to access.

Is there any way via reflection to get the instance reference to class B? The only object I have is my ‘this’ reference.

[ Edit ]

By way of explaining that I’m not totally nuts for needing to do this: My class is T4NmpBase (class A). I have no control over the class in which I am inheriting (TextTransformation) or the class that inherits from me (TextTemplating – class B). I would like to use the “Host” property if it exits but do not want to put any burden on the programmer who is writing the text templating code that generates the TextTransformation class.

//
// this is my class
//
public abstract partial class T4NmpBase : Microsoft.VisualStudio.TextTemplating.TextTransformation {

    public override void Initialize()
    {
        //
        // determine derived class info and get value of "Host" property if it exists
        //
    }

}


//
// this class is generated by T4 in a project that I have no control over
//
[System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.TextTemplating", "10.0.0.0")]
public partial class PPTest : T4_NMP_Base.T4NmpBase {

    public virtual global::Microsoft.VisualStudio.TextTemplating.ITextTemplatingEngineHost Host { ... }

    public override void Initialize()
    {
        base.Initialize();
    }
}

Answer 1

In your case (assuming I follow correctly) your this reference is really your class (B) type, so you can use that to get the value of the property. So, just to make sure I follow correctly, you’ve got something that looks like:

public class ClassA
{
    public virtual void VirtualMethod()
    {
        // Do your property investigation here
    }
}

public class ClassB: ClassA
{
    public override void VirtualMethod()
    {
        // Code for ClassB
    }
}

And you are invoking the virtual method using something like:

ClassA instance = new ClassB();
instance.VirtualMethod()

So if that is the case then you should be able to get the value of the property by:

PropertyInfo proeprtyOnClassB // Assume you got this already via reflection
object propertyValue = propertyOnClassB.GetGetMethod().Invoke(this,null);