VB Coding Tip: Treeview – Changing Colours

This is the second part of the Treeview code series. This week we use API calls to change the background colour of the treeview control, and a few other settings.

'API Call for Sending the message
Private Declare Function _
      SendMessage _
   Lib "user32" Alias _
      "SendMessageA" (ByVal hWnd As Long, _
                ByVal wMsg As Long, _
                ByVal wParam As Long, _
                lParam As Long) As Long 

'Constants for changing the treeview
Private Const GWL_STYLE = -16&
Private Const TVM_SETBKCOLOR = 4381&
Private Const TVM_GETBKCOLOR = 4383&
Private Const TVS_HASLINES = 2&
Private Const TV_FIRST As Long = &H1100
Private Const TVM_GETTEXTCOLOR As Long = _
                          (TV_FIRST + 32)
Private Const TVM_SETTEXTCOLOR As Long = _
                          (TV_FIRST + 30) 

Private Sub Form_Load()
'This is last weeks code
'Declare Variables
Dim mNode As Node
Dim i As Integer
'Populate the list box
List1.AddItem "Node 1"
List1.AddItem "Node 2"
List1.AddItem "Node 3"
'Add the primary node
Set mNode = TreeView1.Nodes.Add()
mNode.Text = "Primary Node"
'Add the nodes from the list box
For i = 0 To List1.ListCount - 1
Set mNode = TreeView1.Nodes.Add(1, tvwChild)
mNode.Text = List1.List(i)
Next i 

'This is this weeks code
'Send a message to the treeview telling it to
'change the background It uses an RGB colour setting
Call SendMessage(TreeView1.hWnd, _
                 TVM_SETBKCOLOR, _
                 0, _
                 ByVal RGB(255, 204, 0))
'Same as above except this one tells it to change
'the text colour
Call SendMessage(TreeView1.hWnd, _
                 TVM_SETTEXTCOLOR, _
                 0, _
                 ByVal RGB(0, 127, 0))
End Sub