建立Floating Window(Top Most的window)

　　事實上是使用SetWindowPos()來改變z-order，所謂z-order是屏幕一般是以x軸y軸

　　來表示位置，而以z軸表示前後位置，這便是z-order

　　bWndInsertAfter的設定值

　　HWND_BOTTOM　　 Places the window at the bottom of the Z order. If the hwnd

　　parameter identifies a topmost window, the window loses its

　　topmost status and is placed at the bottom of all other

　　windows.

　　HWND_NOTOPMOST　Places the window above all non-topmost windows (that is,

　　behind all topmost windows). This flag has no effect if the

　　window is already a non-topmost window.

　　HWND_TOP　　　　Places the window at the top of the Z order.

　　HWND_TOPMOST　　Places the window above all non-topmost windows. The window

　　maintains its topmost position even when it is deactivated.

　　wFlag的設值

　　SWP_DRAWFRAME　　 Draws a frame (defined in the window's class description) around the window.

　　SWP_FRAMECHANGED　Sends a WM_NCCALCSIZE message to the window, even if the window's size is not being changed. If this flag is not specified, WM_NCCALCSIZE is sent only when the window's size is being changed.

　　SWP_HIDEWINDOW　　Hides the window.

　　SWP_NOACTIVATE　　Does not activate the window. If this flag is not set, the window is activated and moved to the top of either the topmost or non-topmost group (depending on the setting of the hwndInsertAfter parameter).

　　SWP_NOCOPYBITS　　Discards the entire contents of the client area. If this flag is not specified, the valid contents of the client area are saved and copied back into the client area after the window is sized or repositioned.

　　SWP_NOMOVE　　　　Retains the current position (ignores the x and y parameters).

　　SWP_NOSIZE　　　　Retains the current size (ignores the cx and cy parameters).

　　SWP_NOREDRAW　　　Does not redraw changes. If this flag is set, no repainting of any kind occurs. This applies to the client area, the nonclient area (including the title bar and scroll bars), and any part of the parent window uncovered as a result of the

　　SWP_NOZORDER　　　Retains the current Z order (ignores the hwndInsertAfter parameter).

　　SWP_SHOWWINDOW　 Displays the window.

　　范例

　　

Const SWP_NOMOVE = &H2
Const SWP_NOSIZE = &H1
Const FLAG = SWP_NOMOVE Or SWP_NOSIZE
Const HWND_TOPMOST = -1
Const HWND_NOTOPMOST = -2
Const HWND_TOP = 0
Const HWND_BOTTOM = 1
Private 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
Private Sub Command1_Click()
Call SetWindowPos(Me.hwnd, HWND_TOPMOST, 0, 0, 0, 0, FLAG)
End Sub
Private Sub Command2_Click()
Call SetWindowPos(Me.hwnd, HWND_NOTOPMOST, 0, 0, 0, 0, FLAG)
End Sub