C#SetWindowPos窗口置頂

　　[DllImport("userdll" CharSet = CharSetAuto)]
private static extern int SetWindowPos(IntPtr hWnd int hWndInsertAfter int x int y int Width int Height int flags);
/// <summary>
/// 得到當前活動的窗口
/// </summary>
/// <returns></returns>
[DllImport("userdll" CharSet = CharSetAuto)]
private static extern SystemIntPtr GetForegroundWindow();

　　哪個窗體想要置頂在Form_Load中加上

　　SetWindowPos(thisHandle | ); //最後參數也有用 | 　
具體說明看API函數說明
如果是用點擊一個按鈕後彈出新窗體並置頂則

　　Form frm = new Form();
frmShow();
SetWindowPos(GetForegroundWindow() | );

From:http://tw.wingwit.com/Article/program/net/201311/14257.html