判断哪个修改键（Shift、Ctrl 和 Alt）处于按下状态的值。

修改键 /// <summary> /// 获取一个表示哪个修改键（Shift、Ctrl 和 Alt）处于按下状态的值。 /// </summary> /// /// <returns> /// <see cref="T:System.Windows.Forms.Keys"/> 值的按位组合。默认值为 <see cref="F:System.Windows.Forms.Keys.None"/>。 /// </returns> /// <filterpriority>2</filterpriority> public static Keys ModifierKeys { get { Keys keys = Keys.None; if ((int) UnsafeNativeMethods.GetKeyState(16) < 0) keys |= Keys.Shift; if ((int) UnsafeNativeMethods.GetKeyState(17) < 0) keys |= Keys.Control; if ((int) UnsafeNativeMethods.GetKeyState(18) < 0) keys |= Keys.Alt; return keys; } } 判断按下状态： var isControlDown = (Control.ModifierKeys & Keys.Control) == Keys.Control; var isAltDown = (Control.ModifierKeys & Keys.Alt) == Keys.Alt; var isShiftDown = (Control.ModifierKeys & Keys.Shift) == Keys.Shift;