SetWindowPos - 改变窗口的位置与状态

//声明:
SetWindowPos(
  hWnd: HWND;            {窗口句柄}
  hWndInsertAfter: HWND; {窗口的 Z 顺序}
  X, Y: Integer;         {位置}
  cx, cy: Integer;       {大小}
  uFlags: UINT           {选项}
): BOOL;

//hWndInsertAfter 参数可选值:
HWND_TOP       = 0;        {在前面}
HWND_BOTTOM    = 1;        {在后面}
HWND_TOPMOST   = HWND(-1); {在前面, 位于任何顶部窗口的前面}
HWND_NOTOPMOST = HWND(-2); {在前面, 位于其他顶部窗口的后面}

//uFlags 参数可选值:
SWP_NOSIZE         = 1;    {忽略 cx、cy, 保持大小}
SWP_NOMOVE         = 2;    {忽略 X、Y, 不改变位置}
SWP_NOZORDER       = 4;    {忽略 hWndInsertAfter, 保持 Z 顺序}
SWP_NOREDRAW       = 8;    {不重绘}
SWP_NOACTIVATE     = $10;  {不激活}
SWP_FRAMECHANGED   = $20;  {强制发送 WM_NCCALCSIZE 消息, 一般只是在改变大小时才发送此消息}
SWP_SHOWWINDOW     = $40;  {显示窗口}
SWP_HIDEWINDOW     = $80;  {隐藏窗口}
SWP_NOCOPYBITS     = $100; {丢弃客户区}
SWP_NOOWNERZORDER  = $200; {忽略 hWndInsertAfter, 不改变 Z 序列的所有者}
SWP_NOSENDCHANGING = $400; {不发出 WM_WINDOWPOSCHANGING 消息}
SWP_DRAWFRAME      = SWP_FRAMECHANGED; {画边框}
SWP_NOREPOSITION   = SWP_NOOWNERZORDER;{}
SWP_DEFERERASE     = $2000;            {防止产生 WM_SYNCPAINT 消息}
SWP_ASYNCWINDOWPOS = $4000;            {若调用进程不拥有窗口, 系统会向拥有窗口的线程发出需求}


//举例:
procedure TForm1.Button1Click(Sender: TObject);
begin
  SetWindowPos(Handle, HWND_TOPMOST, 0,0, 100,200, SWP_SHOWWINDOW);
end;