如果你想讓VB和其他軟件或儀器儀表進行通訊，就會經(jīng)常用到數(shù)值高低位轉換的問題。以下方法可以方便地解決。
一、新建一個模塊，復制下面代碼。
Option Explicit
' 用途：將二進制轉化為十進制
Public Function BIN_to_DEC(ByVal Bin As String) As Long
Dim i As Long
For i = 1 To Len(Bin)
BIN_to_DEC = BIN_to_DEC * 2 + Val(Mid(Bin, i, 1))
Next i
End Function
' 用途: 將十進制轉化為二進制
Public Function DEC_to_BIN(Dec As Long) As String
DEC_to_BIN = ""
Do While Dec > 0
DEC_to_BIN = Dec Mod 2 & DEC_to_BIN
Dec = Dec \ 2
Loop
End Function
' 用途:把數(shù)值轉換為高低字節(jié)形式
' 輸入：strSendVal(要發(fā)送的數(shù) 為整數(shù)型),nSendvalh (轉化后的高位),nSendvall (轉化后的低位)
'返回值：nSendvalh,nSendvall
Sub Val2HL(ByVal strSendVal As Long, nSendvalh As Integer, nSendvall As Integer)
Dim strSendValtoBin As String '將發(fā)送的數(shù)轉化為二進制
Dim strSendValh As String ''二進制高位
Dim strSendVall As String ''二制制低位
If strSendVal < 0 Then strSendVal = 32768 - Abs(strSendVal) '小于0 求補
strSendValtoBin = Format(DEC_to_BIN(strSendVal), "0000000000000000")
strSendValh = Mid(strSendValtoBin, 1, 8)
strSendVall = Mid(strSendValtoBin, 9, 8)
nSendvalh = BIN_to_DEC(strSendValh) + 128
nSendvall = BIN_to_DEC(strSendVall)
End Sub
' 用途:把高低字節(jié)形式還原為原數(shù)值
' 輸入：nSendvalh (轉化后的高位),nSendvall (轉化后的低位)
' 輸出：還原后的數(shù)值
Function HL2Val(ByVal nSendvalh As Integer, ByVal nSendvall As Integer) As Long
Dim strSendValtoBin As String '將發(fā)送的數(shù)轉化為二進制
Dim strSendValh As String ''二進制高位
Dim strSendVall As String ''二制制低位
strSendValh = Format(DEC_to_BIN(CLng(nSendvalh) - 128), "00000000")
strSendVall = Format(DEC_to_BIN(CLng(nSendvall)), "00000000")
HL2Val = BIN_to_DEC(strSendValh & strSendVall)
End Function
二、調用舉例
1、把數(shù)值轉換為高低字節(jié)形式
Dim H As Integer, L As Integer, V As Long
V = 1200
Val2HLV, H, L
Debug.Print H, L (H=132,L=176)
2、把高低字節(jié)形式還原為原數(shù)值
Dim H As Integer, L As Integer, V As Long
H=132
L=176
V=HL2Val(H,L) (V=1200)
