VB - 设定开关键[CapsLock - ScrollLock - NumLock]

方法：借助API来完成
思路：先用 "GetKeyState" 判断开关键的状态，并转换为布尔值，如果打开，则位0为1，此时布尔值为True，然后判断该布尔值与设定布尔值是否相同，如果不同，使用 "MapVirtualKey" 返回开关键码对应的扫描码，最后用到两次 "keybd_event" ，第一次模拟开关键按下，第二次模拟开关键放开。

'以下代码在模块：
Option Explicit
Public Declare Function GetKeyState Lib "user32" (ByVal nVirtKey As Long) As Integer
Public Declare Function MapVirtualKey Lib "user32" Alias "MapVirtualKeyA" (ByVal wCode As Long, _
    ByVal wMapType As Long) As Long
Public Declare Sub keybd_event Lib "user32" (ByVal bVk As Byte, _
    ByVal bScan As Byte, _
    ByVal dwFlags As Long, _
    ByVal dwExtraInfo As Long)
Public Const KEYEVENTF_EXTENDEDKEY = &H1
Public Const KEYEVENTF_KEYUP = &H2

Public Sub SetNumLock(ByVal bLock As Boolean)
    Dim Check As Boolean, ScanCode As Long
    Check = CBool(GetKeyState(vbKeyNumlock))
    If Check <> bLock Then
        ScanCode = MapVirtualKey(vbKeyNumlock, 0)
        Call keybd_event(vbKeyNumlock, ScanCode, 0, 0)
        Call keybd_event(vbKeyNumlock, ScanCode, KEYEVENTF_KEYUP, 0)
    End If
End Sub

Public Sub SetScrollLock(ByVal bLock As Boolean)
    Dim Check As Boolean, ScanCode As Long
    Check = CBool(GetKeyState(vbKeyScrollLock))
    If Check <> bLock Then
        ScanCode = MapVirtualKey(vbKeyScrollLock, 0)
        Call keybd_event(vbKeyScrollLock, ScanCode, 0, 0)
        Call keybd_event(vbKeyScrollLock, ScanCode, KEYEVENTF_KEYUP, 0)
    End If
End Sub

Public Sub SetCapsLock(ByVal bLock As Boolean)
    Dim Check As Boolean, ScanCode As Long
    Check = CBool(GetKeyState(vbKeyCapital))
    If Check <> bLock Then
        ScanCode = MapVirtualKey(vbKeyCapital, 0)
        Call keybd_event(vbKeyCapital, ScanCode, 0, 0)
        Call keybd_event(vbKeyCapital, ScanCode, KEYEVENTF_KEYUP, 0)
    End If
End Sub

'调用示例（这里只例举设定NumLock键，其他两个键调用方法相同）：
    Call SetNumLock(False) '关闭NumLock键
    Call SetNumLock(True) '打开NumLock键