添加一个timer控件  Interval属性为200 
**********模块代码***************
Option Explicit
Public Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long
Public Declare Function GetWindowRect Lib "user32" (ByVal hwnd As Long,lpRect As RECT) As Long
Public Declare Function SetWindowPos Lib "user32" (ByVal hwnd As Long,ByVal hWndInsertAfter As Long,ByVal X As Long,ByVal Y As Long,ByVal cx As Long,ByVal cy As Long,ByVal wFlags As Long) As Long

Public Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type

Public Type POINTAPI
X As Long
Y As Long
End Type

Public Const HWND_TOPMOST = -1
Public Const SWP_NOSIZE = &H1
Public Const SWP_NOMOVE = &H2
Public Const HWND_TOP = 0
Public Const SWP_NOACTIVATE = &H10
Public Const SWP_SHOWWINDOW = &H40

*********窗体程序代码**************
Private Sub Form_Load()
SetWindowPos Me.hwnd,HWND_TOPMOST,SWP_SHOWWINDOW Or SWP_NOMOVE Or SWP_NOSIZE
End Sub

Private Sub Timer1_Timer()
On Error Resume Next
Dim p As POINTAPI
Dim f As RECT
GetCursorPos p
GetWindowRect Me.hwnd,f
If Me.WindowState <> 1 Then
If p.X > f.Left And p.X < f.Right And p.Y > f.Top And p.Y < f.Bottom Then
If Me.Top < 0 Then
Me.Top = -10
Me.Show
ElseIf Me.Left < 0 Then
Me.Left = -10
Me.Show
ElseIf Me.Left + Me.Width >= Screen.Width Then
Me.Left = Screen.Width - Me.Width + 10
Me.Show
End If
ElseIf f.Top <= 4 Then
Me.Top = 40 - Me.Height
ElseIf f.Left <= 4 Then
Me.Left = 40 - Me.Width
ElseIf Me.Left + Me.Width >= Screen.Width - 4 Then
Me.Left = Screen.Width - 40
End If
End If
End Sub
****************END*************************