C#中窗体屏蔽键盘按键

重写Wndproc示例：

static bool flag = false;
protected override void WndProc(ref Message m)
{
switch (m.Msg) {
case 0x0200: //WM_MOUSEMOVE
if (flag)
{
PostMessage(this.Handle, 0x00A1,new IntPtr(2),m.LParam);//这里需要导入 user32.dll
}
break;
case 0x201://WM_LBUTTONDOWN
flag = true;
break;
case 0x202://WM_LBUTTONUP
flag = false;

break;

default:
base.WndProc(ref m);
break;
}

[DllImport("user32.dll", CharSet = CharSet.Unicode)]
public static extern IntPtr PostMessage(IntPtr hwnd, int wMsg, IntPtr wParam, IntPtr lParam);

虚拟键盘代码16进制值 对应键
VK_LBUTTON 01 鼠标左键
VK_RBUTTON 02 鼠标右键
VK_CANCEL 03 用于执行Ctrl+C或Ctrl+Break
VK_MBUTTON 04 鼠标中键
VK_BACK 08 Backspace键
VK_TAB 09 Tab键
VK_CLEAR 0C Clear键
VK_RETURN 0D Enter键
VK_SHIFT 10 Shift键
VK_CONTROL 11 Ctrl键
VK_MENU 12 Arl键
VK_PAUSE 13 Pause键
VK_CAPITAL 14 Capslock键
VK_ESCAPE 1B Ese键
VK_SPACE 20 SpaceBar键
VK_PRIOR 21 PgUp键
VK_NEXT 22 PgDn键
VK_END 23 End键
VK_HOME 24 Home键
VK_LEFT 25 Left Arrow键
VK_UP 26 Up Arrow键
VK_RIGHT 27 Right Arrow键
VK_DOWN 28 Down Arrow键
VK_SELECT 29 Select键
VK_EXECUTE 2B Execute键
VK_SNAPSHOT 2C PrintScreen键
VK_INSERT 2D Ins键
VK_DELECT 2E Del键
VK_HELP 2F Help键
VK_0 30 0键
… … …
VK_9 39 9键
VK_A 41 A键
… … …
VK_Z 5A Z键
VK_NUMAPD0 60 数字板0键
… … …
VK_NUMAPD9 69 数字板9键
VK_MULTIPY 6A 乘号键
VK_ADD 6B 加号键
VK_SEPARATOR 6C Separator键
VK_SUBSTRACT 6D 减号键
VK_DECIMAL 6E小数点键
VK_DIVIDE 6F 除号键
VK_F1 70 F1键
… … …
VK_F24 87 F24键
VK_NUMLOCK 90 NumLock键
VK_SCROLL 91 ScrollLock键

VK_CAPITAL Caps Lock
VK_ESCAPE Esc
VK_SPACE Space
VK_PRIOR Page Up
VK_NEXT Page Down
VK_END End
VK_HOME Home
VK_LEFT 向左方向键
VK_UP
VK_RIGHT
VK_DOWN
VK_DELETE Delete
VK_INSERT Inser
VK_NUMPAD0~VK_NUMPAD9 小键盘上的0-9键
VK_F1-VK_f12 F1-F12键

检测Caps Lock 键：

var
KeyStates:TKeyboardState;

begin

GetKeyboardState(KeyStates);
if Odd(KeyStates[VK_CAPITAL]) then
spBtnA.Caption := 'a'
else
spBtnA.Caption := 'A';

end;