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To serialize the tree view control override the Serialize() function. The Serialize() function is a virtual function defined in Cobject. In the code below we save the outline to a text file and can read it back from a text file. When saving the outline to the archive, tabs are used to indent the item […]

Like any other control, you can handle the WM_CTLCOLOR message for the tree view control too. You can set the background color and it works – kind of. When the control draws the tree items, it ignores the color set by the WM_CTLCOLOR handler and uses the system color. The net effect is that portions […]

The treeview has built in support for expanding expanding the outline one level at a time. If you want to completely expand a branch, the code below will help. It uses recursion to expand all items. The last line, that is, the call to EnsureVisible() is useful when this code is hooked up to a […]

You may have noticed that when you collapse a branch in Explorer and then expand it again later, the effect is that any child branches that were expanded earlier are again expanded. Although, this is mostly helpful, sometimes you want to be able to traverse the outline one level at a time so that you […]

Have you ever had the experience that you have expanded the outline at various points causing a lot of items to be visible and then finding it difficult to locate a particular item. Well, it happens with me all the time. So heres the code that will collapse all the branches in the outline as […]

To limit the length of text that can be entered when editing an item label, you have to add a handler for the TVN_BEGINLABELEDIT notification. Within this handler get the edit control and call the LimitText() function.   void COutline::OnBeginLabelEdit(NMHDR* pNMHDR, LRESULT* pResult)  {         TV_DISPINFO* pTVDispInfo = (TV_DISPINFO*)pNMHDR;                  // Limit text to […]

To allow users to edit the item labels, the treeview control should be created with the TVS_EDITLABELS style. Either you can set this style in the resource editor, or in the call to Create() or in PreCreateWindow() if you are using the CTreeView class. You should then handle the TVN_BEGINLABELEDIT and the TVN_ENDLABELEDIT notifications. You […]

When I first implemented the tree view control and tried editing a label, the only way I could finish editing was to click elsewhere. MFC has been designed in such a way that the parent window gets a chance at the messages using the PreTranslateMessage() virtual function. If the parent window is a CDialog or […]

Have you ever had the experience that you clicked on the Explorer to bring it to the foreground and the directory got moved. This happens if the mouse moves before the mouse button is released. Many of the users of my program had this experience and heres what I did to prevent inadvertant drag – […]

To copy a branch, we use recursion and the CopyItem() function to accomplish our task.   // CopyBranch           – Copies all items in a branch to a new location // Returns              – The new branch node // htiBranch            – The node that starts the branch // htiNewParent – Handle of the parent for new branch […]

Dragging an item with the right mouse button is very similar to dragging it with the left button. When the user begins dragging the item with the right mouse button, Windows sends a TVN_BEGINRDRAG message to the parent window. This can be handled within the control class using MFC message reflection. The steps below explain […]

“Here is a sample I whipped up over lunch and cleaned up after work. It demonstrates something that Outlook 97 and the IE 4.0 tree control do. When you drag an item and hold it over a closed node for 2 seconds it will expand it. I did it in a CTreeView derived class, but […]