mainmodule.bas

师兄做的一个利用VB结合mapx组件做的超市查询小系统

Attribute VB_Name = "MainModule"

Option Explicit

Public Const GWL_WNDPROC = (-4)
Public Const WM_COMMAND = &H111
Public Const WM_MBUTTONDOWN = &H207
Public Const WM_MBUTTONUP = &H208
Public Const WM_MOUSEWHEEL = &H20A

Public Oldwinproc   As Long
Public b_Select As Boolean
Public ModiLegend As Boolean
Public CoordSys As New MapXLib.CoordSys

Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Public 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
Public Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long) As Long

Public Function FlexScroll(ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    Select Case wMsg
        Case WM_MOUSEWHEEL
            Select Case wParam
                Case -7864320     '向下滚
                    SetCurrentScale "ZoomOut", 2
                Case 7864320       '向上滚
                    SetCurrentScale "ZoomIn", 2
          End Select
    End Select
    
    FlexScroll = CallWindowProc(Oldwinproc, hWnd, wMsg, wParam, lParam)
End Function


Private Sub SetCurrentScale(strINorOut As String, dScale As Double)
    If frmMain.MapDisp Is Nothing Then Exit Sub
    
    If strINorOut = "ZoomIn" Then
        frmMain.MapDisp.Zoom = (frmMain.MapDisp.Zoom) * dScale
        frmMain.MapDisp.Refresh
    ElseIf strINorOut = "ZoomOut" Then
        frmMain.MapDisp.Zoom = (frmMain.MapDisp.Zoom) / dScale
        frmMain.MapDisp.Refresh
    End If
End Sub

Public Sub Main()
    b_Select = False
    ModiLegend = False
    frmLogin.Show
End Sub