调用API程序运行怪现象：本来可以用的代码突然不能使用。

qlm

      我用下面的代码判断鼠标是否在列表框内,一开始可以正常使用,但后来就不行了,不知道是什么原因。本来我做了备份,但是现在备份的那一个数据库也不能正常使用，而其它的功能正常。重新启动电脑也没有用。

调用方法是: if_Mouse_over Listbox

然后根据 Mouse_Over变量的值来判断是否出界。

Option Compare Database
Public Mouse_Over As Boolean

Private Declare Function ClipCursor Lib "user32" (lpRect As Any) As Long
Private Declare Function ClipCursorBynum& Lib "user32" Alias "ClipCursor" (ByVal lpRect As Long)
Private Declare Function ClientToScreen Lib "user32" (ByVal hwnd As Long, lpPoint As POINTAPI) As Long

Private Type POINTAPI
        X As Long
        Y As Long
End Type

Public RetValue As Long

Public Sub If_Mouse_Over(ClipObject As ListBox)
Dim CurrentPoint As POINTAPI
   
    If IsNull(ClipObject) Then Exit Sub

Mouse_Over = False
    With CurrentPoint
        .X = 0
        .Y = 0
    End With
    RetValue = ClientToScreen(ClipObject, CurrentPoint)        
If CurrentPoint.X > ClipObject.Left + ClipObject.Width Or CurrentPoint.X < ClipObject.Left Or CurrentPoint.Y < ClipObject.Top Or CurrentPoint.Y > ClipObject.Top + ClipObject.Height Then Mouse_Over = True
End Sub