23.txt

VB文章集（含API、窗口、数据库、多媒体、系统、文件、等等）

捕捉 MouseExit 事件   
       
MouseDown、MouseUp、MouseMove。VB 似乎提供了很好的 Mouse 事件。但好象还缺少什么！对！还差 MouseExit（鼠标移出）事件。在 VB 中，我们要捕捉 MouseExit 事件，必须用 API 函数：
Private Declare Function SetCapture Lib "user32" (ByVal hWnd As Long) As Long
Private Declare Function ReleaseCapture Lib "user32" () As Long
然后，我们可以在控件（以 Picture1 为例）的 MouseMove 事件上加上以下代码：

With Picture1 'Change this to the name of the control
If Button = 0 Then
If (X < 0) Or (Y < 0) Or (X > .Width) Or (Y > .Height) Then
'Mouse pointer is outside button, so let other controls receive
'mouseevents too:
ReleaseCapture
' 放入鼠标离开的代码
Else
' Mouse pointer is over button, so we'll capture it, thus
' we'll receive mouse messages even if the mouse pointer is
' not over the button
SetCapture .hwnd

' 放入鼠标进入的代码
End If