Change method from dll C#

Question

I'm using avalondock 2.0 dll in my solution and I need to change IOverlayWindowHost.GetDropAreas method from DockingManager.cs at another project. But, I don't want to do this at the source file. The method is not virtual and I can't just override it like this

class CustomDockingManager : DockingManager
{
     override IEnumerable<IDropArea> GetDropAreas(LayoutFloatingWindowControl draggingWindow)
     {
          //some changes
     }
}

Ivan Stoev · Answer 1 · 2015-12-28T18:29:41.097

Although not recommended in general, you can use the C# ability to reimplement explicitly just a single method of an interface, like this

class CustomDockingManager : DockingManager, IOverlayWindowHost
{
    IEnumerable<IDropArea> IOverlayWindowHost.GetDropAreas(LayoutFloatingWindowControl draggingWindow)
    {
        // ...
    }
}

Note that this way you cannot use the base implementation, you have to write the method from scratch.

score 1 · Accepted Answer · edited May 23 '17 at 11:59

You would need to do IL weaving to change a non-virtual method. You've many options here.

Mono.Cecil. Check this other Q&A that might give you some direction on how to solve your issue: C# Intercept/change/redirect a method
PostSharp. If you just want to add some code before and after some method execution, PostSharp makes it easier than emitting intermediate language by hand. You would do it using an OnMethodBoundaryAspect attribute. See this article to get in touch with method aspects: http://www.postsharp.net/blog/post/Day-4-OnMethodBoundaryAspect

Change method from dll C#

2 Answers2