[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern short GetAsyncKeyState(int nVirtKey);
if (GetAsyncKeyState(40) < 0) //40为下箭头对应键asc码
{
}
2013-7-22判断键盘上某键抬起按下状态
原文：http://www.cnblogs.com/mol1995/p/5965137.html
