Private Const TV_FIRST = &H1100
Private Const TVM_SETBKCOLOR = (TV_FIRST + 29)
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Private Sub Form_Load()
Call SetTreeViewBkColor(TreeView1.hwnd, RGB(100, 0, 100))
End Sub
Sub SetTreeViewBkColor(ByVal hTVWnd As Long, ByVal clr As Long)
SendMessage hTVWnd, TVM_SETBKCOLOR, 0, ByVal clr
End Sub