Question

I had created a drag and drop control in wpf to drag and drop data between two list boxes which worked as a charm until I moved it to another project.

The difference being It was initially a wpf window and used the window object to get the mouse position and the position of the controls inside.

this.topWindow = Window.GetWindow(this.sourceItemsControl); //Source items control is instance of ItemsControl

bool previousAllowDrop = this.topWindow.AllowDrop;
this.topWindow.AllowDrop = true;

and now I had to change it to a user control instead, since its a part of a bigger project which is a Windows forms project and the views are linked as a Smart Part from the main project. So now the Window object is null.

I looked for a similar functionality for User Control but could not find it..What is it that I am missing out?? I know there should be something..Would appreciate any help on the same..

P.S. : I am using the MVVM architecture

Answer 1

Found the way to find the base User control using recursion, Thanks to ekholm for the heads up..

public static UserControl FindParentControl(DependencyObject child)
        {
            DependencyObject parent = VisualTreeHelper.GetParent(child);

            //CHeck if this is the end of the tree
            if (parent == null) return null;

            UserControl parentControl = parent as UserControl;
            if (parentControl != null)
            {
                return parentControl;
            }
            else
            {
                //use recursion until it reaches a Window
                return FindParentControl(parent);
            }
        } 

Now this base user control can be used to find the coordinates (reference) as well as setting other properties like AllowDrop, DragEnter, DragOver etc.