This demonstration shows you how to implement drag and drop functionality in a Windows Form. Drag-and-drop is one of the fundamental metaphors underlying the Microsoft® Windows® family of operating systems. Users understand that some items can be moved around by holding the mouse down on them, and that they'll get appropriate visual feedback when they're over a spot where the item can be dropped. They expect to be able to move data and images from one spot to another this way. Visual Basic .NET makes it easy to implement drag-and-drop in your own applications. You can control all aspects of the process, including which controls allow dragging, what data they make available to drag, and where it can be dropped. You can implement this both within a single application and between applications. In this How To, you'll learn how to manage drag-and-drop in Visual Basic .NET.
This application has three examples of drag and drop:
a) From a TextBox control to two other TextBox controls, one of which does not have the AllowDrop property set to True, demonstrating how to prevent a drop on a control.
b) From a TreeView control to another TreeView control, demonstrating how to move nodes from one to the other.
c) From a PictureBox to another PictureBox, demonstrating how to copy images from one to the other.
You can do a Copy or a Move when you drag and drop. To copy, hold down the Ctrl key while dragging. When you do this notice the Copy-Drop symbol (rectangle with + sign). The Move symbol is just the rectangle.
Microsoft Visual Studio.NET Professional or greater.
Windows 2000 or Windows XP
There are no special instructions for running the sample. However, consider the following when coding drag-and-drop operations:
1. In Version 1.0 of Visual Studio .NET there is no way to set the AllowDrop property of the PictureBox using the Forms designer. Currently you have to set this property directly in the code.
2. The data to be dragged should be an instance of the String, Bitmap, or MetaFile class, or an object that implements the ISerializable or IDataObject interfaces.
If you run this sample in Visual Studio 2003 you will be asked to convert the solution and its projects to the formats used by the 2003 version of Visual Studio .NET.
If you choose to convert this solution, all of its projects will be converted as well, once a solution or any of its projects has been converted, it can no longer be edited, built or run in previous versions of Visual Studio. If you choose not to convert this solution, it will be closed.