https://learn.microsoft.com/en-us/dotnet/api/system.windows.dragdrop.removedragoverhandler?view=netframework-4.8.1&viewFallbackFrom=windowsdesktop-10.0
DragDrop.RemoveDragOverHandler(DependencyObject, DragEventHandler) Method (System.Windows) |...
Removes a DragOver event handler from a specified dependency object.
dragdropmethodsystemwindows