How to do drag and drop on vce designer code#
How to do drag and drop on vce designer windows#

/ Defines the handler object of a drop operationДragEffects GetDropEffects(IDraggedData dataObject)

/ Optional object for additional informationДragEffects GetDragEffects( object dataContext) / A dictionary with the format as the key and the data in that format in the value / Holds the data of a dragged object in a drag-and-drop operation. Therefore, the solution is to change the IsDragSource and IsDropTarget to DragSource and DropTarget properties that accept objects of type IDragSource and IDropTarget containing all the methods needed for the events in question: Besides, we want it simple, we don't really want the user of the system to care about the drag and drop inner workings. We could, of course, link all events to commands, but that would be very cumbersome to use. The classes responsible with the decisions for the drop permissions and actions should be in the ViewModel. We can do this using boolean IsDragSource and IsDropTarget Attached Properties once set they will force a bind of the drag and drop events to some special handlers that would then direct decisions to ICommands.ДЄs we are doing it in MVVM, we don't use the elements directly, but the data they represent, so we work with dragging and dropping commands using data objects. Also, we need a container that can be marked as a drop target. First of all, we need the ability to mark any element as a drag item.

Doing everything using the Model-View-ViewModel patternДЇrom these requirements we can form a basic idea of the way we would like this to work.

Changing an application that works but has no drag and drop in an easy and maintainable way.

Allowing for drag and drop between applications.

How to do drag and drop on vce designer windows#

Allowing for drag and drop between Windows.

Changing the appearance of the drop target while dragging something over.

Changing the appearance of the original dragged element while dragging.

Showing the target can or cannot be dropped.

Ok then, let's define the requirements of this system. Finally Jason Young, for writing about MVVM Drag and Drop, but without the graphic part. Then Lee Roth and Bea Stollnitz/Costa for the ideas about using adorners to show the drag and drop items. I have Sascha Barber to thank for his comprehensive articles on WPF, especially the ones about his Cinch framework.

How to do drag and drop on vce designer code#

I will make sure, though, to put much code directly in this post.ДЇirst a bit of thanks to the people that inspired me to work on that. The framework itself is work in progress and untested in a real life project, so this might have to wait, as well. The solution, I guess, is to make separate articles for the main features in the framework, then present the project as a whole in the end. I mean, you want to show MVVM drag and drop, you should also have Views and ViewModels and base classes and helpers and everything. If you want to do it using MVVM, you have another thing coming.Дisclaimer: Now, I have found a good solution for all the problems above, but the drag and drop behaviour is part of a larger framework that I have been working on and creating a separate project just for it might prove difficult. It is completely event driven and has nothing in the way of actual graphical feedback of what is going on except making the mouse cursor look different. Boy,was I wrong! The mechanism for this has remained almost unchanged from the Windows Forms version. When I first tried to do drag and drop in WPF I thought it would be something easy like DragAndDrop.IsDraggable='True'.