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''''将某位设置为1并返回值
Public Function BitSet32(Number As Long, Bit As Long) As Long
BitSet32 = BitPower(Bit) Or Number
End Function
''''无符号扩展,最好作为内嵌到函数内部，减少调用开支。 注意，它与Clng有本质的区别
Public Function WORD2DWORD(Num As Integer) As Long
WORD2DWORD = Num And &HFFFF&
End Function
''''逻辑右移32位函数
Public Function SHR32(ByRef Num As Long, BitNum As Long) As Long
SHR32 = CallWindowProc(ByVal SHR32Addr, Num, BitNum, 0, 0)
End Function
''''逻辑左移32位函数
Public Function SHL32(ByRef Num As Long, BitNum As Long) As Long
SHL32 = CallWindowProc(ByVal SHL32Addr, Num, BitNum, 0, 0)
End Function
''''没有采用汇编码，如果需要也可以采用，但16位的汇编码较32位的差很多，此函数速度约比SHR32慢一倍左右还可以
Public Function SHR16(ByRef Num As Integer, BitNum As Long) As Integer
Dim mdw As BIT_DWORD
Dim rl As Long
mdw.LoWord = Num
CopyMemory rl, mdw, 4
rl = CallWindowProc(ByVal SHR32Addr, rl, BitNum, 0, 0)
CopyMemory SHR16, rl, 2
End Function
Public Function SHL16(ByRef Num As Integer, BitNum As Long) As Integer
Dim mdw As BIT_DWORD
Dim rl As Long
mdw.LoWord = Num
CopyMemory rl, mdw, 4
rl = CallWindowProc(ByVal SHL32Addr, rl, BitNum, 0, 0)
CopyMemory SHL16, rl, 2
End Function
''''///////////////////////////////////////////////////////////////////////////////////////////
'''' 如果对性能没有太大要求，或没能理解上面的函数的作法，可以用以下几个函数。
'''' 一般不建议使用
Public Function HiByte(ByRef Num As Integer) As Byte
Dim mw As BIT_WORD
CopyMemory mw, Num, 2
HiByte = mw.HiByte
End Function
Public Function LoByte(ByRef Num As Integer) As Byte
CopyMemory LoByte, Num, 1 ''''可以省掉一次取值，
End Function
Public Function HiWord(ByRef Num As Long) As Integer
Dim mdw As BIT_DWORD
CopyMemory mdw, Num, 4
HiWord = mdw.HiWord
End Function
Public Function LoWord(ByRef Num As Long) As Integer
CopyMemory LoWord, Num, 2
End Function
''''比LoWord更快一点的版本(但如果内置于一个大函数内，可能用loword更好，因为代码更清晰）
Public Function LoWordFaster(ByRef Num As Long) As Integer
If (Num And &H8000&) Then '''' dw And &H00008000 来进行确定低位是不是负数
LoWordFaster = Num Or &HFFFF0000
Else
LoWordFaster = Num And &HFFFF& ''''dw And &H0000FFFF
End If
End Function
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