Drag and Drop between Tree controls

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  • Your email address will not be published.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 impact of a data loss event can be significant. Real-time data is essential to remaining competitive. Many companies can no longer afford to rely on a truck arriving each day to take backup tapes offsite. For most companies, a cloud backup and recovery solution will eliminate, or significantly reduce, IT resources related to the mundane task of backup and allow your resources to be redeployed to more strategic projects. The cloud - can now be comfortable for you – with 100% recovery from anywhere all …

  • With JRebel, developers get to see their code changes immediately, fine-tune their code with incremental changes, debug, explore and deploy their code with ease (both locally and remotely), and ultimately spend more time coding instead of waiting for the dreaded application redeploy to finish. Every time a developer tests a code change it takes minutes to build and deploy the application. JRebel keeps the app server running at all times, so testing is instantaneous and interactive.

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds