https://learn.microsoft.com/ja-jp/dotnet/api/system.windows.dragdrop.removepreviewgivefeedbackhandler?view=netframework-4.8.1&viewFallbackFrom=windowsdesktop-10.0
DragDrop.RemovePreviewGiveFeedbackHandler Method (System.Windows) | Microsoft Learn
Removes a PreviewGiveFeedback event handler from a specified dependency object.
dragdropmethodsystemwindowsmicrosoft