PS:mouseOver事件已解决。如下
Private Declare Function SetCapture Lib "user32" (ByVal hWnd As Long) As Long
Private Declare Function ReleaseCapture Lib "user32" () As Long
Private Sub Picture1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Dim mouseOver As Boolean
mouseOver = (X > 0 And X < Picture1.Width) And (Y > 0 And Y < Picture1.Height)
If mouseOver Then
SetCapture Picture1.hWnd
Picture1.BorderStyle = 1
Else
ReleaseCapture
Picture1.BorderStyle = 0
End If
End Sub