有没有办法让标准的 Windows 窗体应用程序检测Shift在应用程序启动时是否按住键 - 不使用 Windows 挂钩？
理想情况下，如果在运行 EXE 文件时按住 shift 键，我希望工作流程能够从正常状态改变。
问问题
5954 次
5 回答
18
ModifierKeys 属性看起来很理想：
private void Form1_Load(object sender, EventArgs e)
{
if ( (ModifierKeys & Keys.Shift) != 0)
{
MessageBox.Show("Shift is pressed");
}
}
于 2009-06-09T00:28:23.947 回答
6
我意识到这已经很老了，但是看到人们为此苦苦挣扎，我有点困扰。ModifierKeys 是一个位字段，因此依靠 .ToString() 或 == 来查看是否按下了 Shift 键，充其量是不可靠的，并且不是正确使用位字段：
public enum ModifierKeys
{
/// <summary>No modifiers are pressed.</summary>
None = 0,
/// <summary>The ALT key.</summary>
Alt = 1,
/// <summary>The CTRL key.</summary>
Control = 2,
/// <summary>The SHIFT key.</summary>
Shift = 4,
/// <summary>The Windows logo key.</summary>
// Windows = 8, No longer leaked
}
可以不按下 Alt、Control 或 Shift 或任何组合，因此检查应为：
if ((ModifierKeys & Keys.Shift) != 0)
{
MessageBox.Show("Shift is pressed");
}
一旦我获得这样做的权利，我就会对 Dan 的回答投赞成票 :-) .Net 4+ 也包括 HasFlag() 方法，但我习惯于按位运算，所以我没有使用它。有关按位运算、标志、（带有）真值表和其他花絮的更多信息，请参阅：
你在源代码中看到的更有趣：
/// <devdoc>
/// Retrieves the current state of the modifier keys. This will check the
/// current state of the shift, control, and alt keys.
/// </devdoc>
public static Keys ModifierKeys {
get {
Keys modifiers = 0;
// SECURITYNOTE : only let state of Shift-Control-Alt out...
//
if (UnsafeNativeMethods.GetKeyState((int)Keys.ShiftKey) < 0) modifiers |= Keys.Shift;
if (UnsafeNativeMethods.GetKeyState((int)Keys.ControlKey) < 0) modifiers |= Keys.Control;
if (UnsafeNativeMethods.GetKeyState((int)Keys.Menu) < 0) modifiers |= Keys.Alt;
return modifiers;
}
}
此实现仅发出 Shift、Control 和 Alt 的状态。不包括 Windows 的键状态。
如果您想在创建表单或控件之前检测关键状态，也许在 Main() 方法中，您可能会发疯。
也许你想这样做：
if (VirtualKeyState.VK_SHIFT.IsKeyPressed())
{
Debugger.Launch();
}
创建一个简单的扩展方法：
public static class KeyAssist
{
public const int KEY_PRESSED = 0x8000;
public static bool IsKeyPressed(this VirtualKeyState key) => Convert.ToBoolean(Native.GetKeyState(key) & KEY_PRESSED);
}
进口：
[DllImport("user32.dll")]
public static extern short GetKeyState(VirtualKeyState virtualKeyState);
创建以下枚举（或一些小节，如果你愿意的话）（来自 PInvoke）：
public enum VirtualKeyState
{
VK_LBUTTON = 0x01,
VK_RBUTTON = 0x02,
VK_CANCEL = 0x03,
VK_MBUTTON = 0x04,
VK_XBUTTON1 = 0x05,
VK_XBUTTON2 = 0x06,
VK_BACK = 0x08,
VK_TAB = 0x09,
VK_CLEAR = 0x0C,
VK_RETURN = 0x0D,
VK_SHIFT = 0x10,
VK_CONTROL = 0x11,
VK_MENU = 0x12,
VK_PAUSE = 0x13,
VK_CAPITAL = 0x14,
VK_KANA = 0x15,
VK_HANGEUL = 0x15,
VK_HANGUL = 0x15,
VK_JUNJA = 0x17,
VK_FINAL = 0x18,
VK_HANJA = 0x19,
VK_KANJI = 0x19,
VK_ESCAPE = 0x1B,
VK_CONVERT = 0x1C,
VK_NONCONVERT = 0x1D,
VK_ACCEPT = 0x1E,
VK_MODECHANGE = 0x1F,
VK_SPACE = 0x20,
VK_PRIOR = 0x21,
VK_NEXT = 0x22,
VK_END = 0x23,
VK_HOME = 0x24,
VK_LEFT = 0x25,
VK_UP = 0x26,
VK_RIGHT = 0x27,
VK_DOWN = 0x28,
VK_SELECT = 0x29,
VK_PRINT = 0x2A,
VK_EXECUTE = 0x2B,
VK_SNAPSHOT = 0x2C,
VK_INSERT = 0x2D,
VK_DELETE = 0x2E,
VK_HELP = 0x2F,
VK_LWIN = 0x5B,
VK_RWIN = 0x5C,
VK_APPS = 0x5D,
VK_SLEEP = 0x5F,
VK_NUMPAD0 = 0x60,
VK_NUMPAD1 = 0x61,
VK_NUMPAD2 = 0x62,
VK_NUMPAD3 = 0x63,
VK_NUMPAD4 = 0x64,
VK_NUMPAD5 = 0x65,
VK_NUMPAD6 = 0x66,
VK_NUMPAD7 = 0x67,
VK_NUMPAD8 = 0x68,
VK_NUMPAD9 = 0x69,
VK_MULTIPLY = 0x6A,
VK_ADD = 0x6B,
VK_SEPARATOR = 0x6C,
VK_SUBTRACT = 0x6D,
VK_DECIMAL = 0x6E,
VK_DIVIDE = 0x6F,
VK_F1 = 0x70,
VK_F2 = 0x71,
VK_F3 = 0x72,
VK_F4 = 0x73,
VK_F5 = 0x74,
VK_F6 = 0x75,
VK_F7 = 0x76,
VK_F8 = 0x77,
VK_F9 = 0x78,
VK_F10 = 0x79,
VK_F11 = 0x7A,
VK_F12 = 0x7B,
VK_F13 = 0x7C,
VK_F14 = 0x7D,
VK_F15 = 0x7E,
VK_F16 = 0x7F,
VK_F17 = 0x80,
VK_F18 = 0x81,
VK_F19 = 0x82,
VK_F20 = 0x83,
VK_F21 = 0x84,
VK_F22 = 0x85,
VK_F23 = 0x86,
VK_F24 = 0x87,
VK_NUMLOCK = 0x90,
VK_SCROLL = 0x91,
VK_OEM_NEC_EQUAL = 0x92,
VK_OEM_FJ_JISHO = 0x92,
VK_OEM_FJ_MASSHOU = 0x93,
VK_OEM_FJ_TOUROKU = 0x94,
VK_OEM_FJ_LOYA = 0x95,
VK_OEM_FJ_ROYA = 0x96,
VK_LSHIFT = 0xA0,
VK_RSHIFT = 0xA1,
VK_LCONTROL = 0xA2,
VK_RCONTROL = 0xA3,
VK_LMENU = 0xA4,
VK_RMENU = 0xA5,
VK_BROWSER_BACK = 0xA6,
VK_BROWSER_FORWARD = 0xA7,
VK_BROWSER_REFRESH = 0xA8,
VK_BROWSER_STOP = 0xA9,
VK_BROWSER_SEARCH = 0xAA,
VK_BROWSER_FAVORITES = 0xAB,
VK_BROWSER_HOME = 0xAC,
VK_VOLUME_MUTE = 0xAD,
VK_VOLUME_DOWN = 0xAE,
VK_VOLUME_UP = 0xAF,
VK_MEDIA_NEXT_TRACK = 0xB0,
VK_MEDIA_PREV_TRACK = 0xB1,
VK_MEDIA_STOP = 0xB2,
VK_MEDIA_PLAY_PAUSE = 0xB3,
VK_LAUNCH_MAIL = 0xB4,
VK_LAUNCH_MEDIA_SELECT = 0xB5,
VK_LAUNCH_APP1 = 0xB6,
VK_LAUNCH_APP2 = 0xB7,
VK_OEM_1 = 0xBA,
VK_OEM_PLUS = 0xBB,
VK_OEM_COMMA = 0xBC,
VK_OEM_MINUS = 0xBD,
VK_OEM_PERIOD = 0xBE,
VK_OEM_2 = 0xBF,
VK_OEM_3 = 0xC0,
VK_OEM_4 = 0xDB,
VK_OEM_5 = 0xDC,
VK_OEM_6 = 0xDD,
VK_OEM_7 = 0xDE,
VK_OEM_8 = 0xDF,
VK_OEM_AX = 0xE1,
VK_OEM_102 = 0xE2,
VK_ICO_HELP = 0xE3,
VK_ICO_00 = 0xE4,
VK_PROCESSKEY = 0xE5,
VK_ICO_CLEAR = 0xE6,
VK_PACKET = 0xE7,
VK_OEM_RESET = 0xE9,
VK_OEM_JUMP = 0xEA,
VK_OEM_PA1 = 0xEB,
VK_OEM_PA2 = 0xEC,
VK_OEM_PA3 = 0xED,
VK_OEM_WSCTRL = 0xEE,
VK_OEM_CUSEL = 0xEF,
VK_OEM_ATTN = 0xF0,
VK_OEM_FINISH = 0xF1,
VK_OEM_COPY = 0xF2,
VK_OEM_AUTO = 0xF3,
VK_OEM_ENLW = 0xF4,
VK_OEM_BACKTAB = 0xF5,
VK_ATTN = 0xF6,
VK_CRSEL = 0xF7,
VK_EXSEL = 0xF8,
VK_EREOF = 0xF9,
VK_PLAY = 0xFA,
VK_ZOOM = 0xFB,
VK_NONAME = 0xFC,
VK_PA1 = 0xFD,
VK_OEM_CLEAR = 0xFE
}
无论如何，这仅供参考，因此没有太多猜测。
高温下，
科尔比
于 2018-09-28T00:21:21.787 回答
4
检查 Control.ModifierKeys ...
[STAThread]
static void Main(string[] args)
{
if (Control.ModifierKeys == Keys.ShiftKey)
{
// Do something special
}
}
于 2009-06-09T00:25:53.047 回答
0
我知道这篇文章相当陈旧，但我遇到了这个问题并通过修改 Jamie 的代码来修复它：
[STAThread]
static void Main(string[] args)
{
if (Control.ModifierKeys.ToString() == "Shift")
{
// Do something special
}
}
于 2017-02-25T02:22:15.283 回答
-1
这是一篇关于直接读取关键状态（和鼠标）的文章。
于 2009-06-09T00:21:07.580 回答