Inserting items at the root level

The very first item you insert does not have any sibling for specifying a relative position, so you cannot use the InsertItem function—you must use InsertItemFirst or InsertItemLast. For an item inserted at the root level, you specify 0 as its parent.

This sample code is in a user event triggered from the Open event of the window containing the TreeView. It assumes two instance variable arrays:

• A string array called item_label that contains labels for all the items that will be inserted at the root level (here composer names)

• An integer array that has values for the Data property (the century for each composer); the century value is for user-defined sorting:

  int ct
  long h_item = 0
  treeviewitem tvi
  
  FOR ct = 1 TO UpperBound(item_label)
        tvi.Label = item_label[ct]
        tvi.Data = item_data[ct]
        tvi.PictureIndex = 1
        tvi.SelectedPictureIndex = 2
        tvi.Children = TRUE
        tvi.StatePictureIndex = 0
        tvi.DropHighlighted = TRUE
        h_item = tv_1.InsertItemSort(0, tvi)
  NEXT
  

After inserting all the items, this code scrolls the TreeView back to the top and makes the first item current:

// Scroll back to top
h_item = tv_1.FindItem(RootTreeItem!, 0)
tv_1.SetFirstVisible(h_item)
tv_1.SelectItem(h_item)