combobox控件的消息.bas

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Attribute VB_Name = "Module1"
Option Explicit

Public Const GWL_WNDPROC = (-4)
Public Const CBN_CLOSEUP = 8
Public Const CBN_SELENDCANCEL = 10
Public Const CBN_SELENDOK = 9

Public Const WM_COMMAND = &H111

Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long) As Long
Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long

Public prevWndProc As Long

Function WndProc(ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    If Msg = WM_COMMAND Then
        Select Case wParam \ 65536
            Case CBN_CLOSEUP
                If lParam = Form1.Combo1.hWnd Then
                    Form1.List1.AddItem "Combo1被收起来了"
                ElseIf lParam = Form1.Combo2.hWnd Then
                    Form1.List1.AddItem "Combo2被收起来了"
                End If
            Case CBN_SELENDOK
                If lParam = Form1.Combo1.hWnd Then
                    Form1.List1.AddItem "Combo1 被收起来了, 使用者选择某一个选项"
                ElseIf lParam = Form1.Combo2.hWnd Then
                    Form1.List1.AddItem "Combo2 被收起来了, 使用者选择某一个选项"
                End If
            Case CBN_SELENDCANCEL
                If lParam = Form1.Combo1.hWnd Then
                    Form1.List1.AddItem "Combo1 被收起来了, 使用者放弃选择"
                ElseIf lParam = Form1.Combo2.hWnd Then
                    Form1.List1.AddItem "Combo2 被收起来了, 使用者放弃选择"
                End If
        End Select
    End If
    
    WndProc = CallWindowProc(prevWndProc, hWnd, Msg, wParam, lParam)
End Function