Difference between revisions of "Programmatically edit a treeview label"

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Latest revision as of 10:46, 25 March 2020

The problem

The normal treeview class does not have a method of putting your treeview item into "edit mode" programmatically. Of course you can do this in the treeview when you are using it, but sometimes you have a need to set this state without requiring user interaction.

As if is a standard windows control, you can send it windows messages yourself. The message to send is TVM_EDITLABEL

Getting it to work

First you have to enable label editing with:

 Set TreeEditLabelsState to True

Then you have to send TVM_EDITLABEL for example as in:

 Procedure EditNow
    Handle hItem
    Handle hWnd
    Integer iResult
 
    Get CurrentTreeItem to hItem
    Get Window_Handle to hWnd
    Move (SendMessage(hWnd,TVM_EDITLABEL,0,hItem)) to iResult
 End_Procedure

 On_Key Key_Alt+Key_F1 Send EditNow

As you can see I've not tested with doing it just after adding the item but in the moment that the control is waiting for user action. Normally the F2 is used so you might replace Alt+F1 with the F2 key, I did not do this to see if my code was really used instead of build in techniques.

Enable editmode on a new item

First, you need the Window_Handle of the control you want to send the message to. This means you can send this message ONLY when the controls is paged. Second, you need the handle of the treeviewitem to edit. Third, the property TreeEditLabelState is a treeview property and not for the item.

Correct syntax would be

  Procedure AddAndEditItem
    Handle hItem
    Get AddTreeItem of oTreeView1 "New item"  0 0 0 0 To hItem
    Set ItemData of oTreeView1 Item hItem to 999
 
    Get Window_Handle of oTreeView1 to hWnd
    If (hWnd <> 0) Begin
        Set TreeEditLabelsState of oTreeView1 to True
        Move (SendMessage(hWnd,TVM_EDITLABEL,0,hItem)) to iResult
        Set TreeEditLabelsState of oTreeView1 to False
    End
  End_Procedure

Depending on the version of VDF you are using you have the following events and properties

 pbCancelEdit
 OnBeginLabelEdit
 OnEndLabelEdit

These are documented in the Help system

External references

Automatic Edit item label in Treeview

Put label in Editmode immediately

MSDN TVM_EDITLABEL Message