下面把鼠标的移动区域限制在(100,100,200,200)

var rect:TRect;
begin
  rect.Left:=100;
  rect.Top:=100;
  rect.Bottom:=200;
  rect.Right:=200;
  windows.ClipCursor(@rect);



下面恢复鼠标的移动区域
  windows.ClipCursor(0);

具体的列子就不用举了吧，很简单的。嘻嘻嘻嘻嘻

在delphi中的帮助是这么写的：

The ClipCursor function confines the cursor to a rectangular area on the screen.
If a subsequent cursor position (set by the SetCursorPos function or the mouse)
lies outside the rectangle, Windows automatically adjusts the position to keep the
cursor inside the rectangular area.

BOOL ClipCursor(

    CONST RECT *lpRect     // pointer to structure with rectangle 
  );    


Parameters

lprc

Points to the RECT structure that contains the screen coordinates of the upper-
left and lower-right corners of the confining rectangle. If this parameter is
NULL, the cursor is free to move anywhere on the screen.



Return Values

If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The cursor is a shared resource. If an application confines the cursor, it must
release the cursor by using ClipCursor before relinquishing control to another
application.
The calling process must have WINSTA_WRITEATTRIBUTES access to the window station.