Drag and Drop between Tree controls

WEBINAR: On-demand webcast

How to Boost Database Development Productivity on Linux, Docker, and Kubernetes with Microsoft SQL Server 2017 REGISTER >

Environment: VC6 SP2, NT4 SP5

This article demonstrates drag and drop between tree controls using OLE Drag and Drop. It also allows an item to be dropped on same tree control.When an item is dropped all the children of that item are also dropped on the target. The following key combination can be used:

  • Left button, to copy an item
  • Ctrl+Left Button,to copy an item
  • Shift+Left Button,to move an item

There are two classes :

  • CDragDropTreeCtrl, for Tree control. This class also has a helper function AddItem() for adding an item to the tree control.
  • CTreeDropTarget, which provides functionality of Drop target

The CDragDropTreeCtrl registers the tree control as the drop target and starts the drag operation in respose to the TVN_BEGINDRAG message.

The CTreeDropTarget is derived from COleDropTarget and serves as drop target. This class overides the following functions:

  • OnDragEnter().
  • OnDragOver(). This function highlights and expands the item under the mouse pointer and also scrolls the tree control appropriately
  • OnDrop(). This function creates the item being dragged in the destination tree control when the user releases the mouse button.
What you have to do You need to do the following things:
  • #include afxole.h in stdafx.h
  • Call AfxOleInit() in InitInstance().
  • Create an object of CDragDropTreeCtrl in your class.

Downloads

Download demo project - 18 Kb
Download source - 5 Kb


Comments

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • The software-defined data center (SDDC) and new trends in cloud and virtualization bring increased agility, automation, and intelligent services and management to all areas of the data center. Businesses can now more easily manage the entire lifecycle of their applications and services via the SDDC. This Aberdeen analyst report examines how a strong foundation in both the cloud and internal data centers is empowering organizations to fully leverage their IT infrastructure and is also preparing them to be able …

  • IT is in a continual battle to simplify and "do more with the same, or less," but the continued growth of data has drastically increased the complexity and cost of deploying, managing, and processing data using traditional IT infrastructure components. One key component — enterprise storage and the underlying software that controls the storage — is fortunately evolving nearly as fast as the data is growing. This ESG Lab Review documents the results of hands-on testing of the WekaIO Matrix …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date