vb.netcrc检验 vbv验证

vb如何实现CRC12校验

Private Sub Form_Load()

'text1为校验对象

Text1.Text = "31303432"

'text2为校验多项式

Text2.Text = "180D"

End Sub

Private Sub Command1_Click()

Text3.Text = CRC(Text1.Text, Text2.Text, 12)

End Sub

Private Function CRC(ByVal Hex_Number As String, ByVal Hex_CRC As String, Optional ByVal C As Integer = 16) As String

'Hex_Number为校验项16进制数字，Hex_CRC为校验多项式，16进制，C为默认位数CRC-16

Dim i As Integer

Dim BinNumber As String

Dim BinCRC As String

Dim Temp As String

CRC = "0"

If Hex_Number = "0" Then Exit Function

BinNumber = HEXtoBin(Hex_Number)

BinCRC = HEXtoBin(Hex_CRC)

i = Len(BinCRC)

BinNumber = BinNumber String(C, "0")

CRC = Left(BinNumber, i)

Temp = Right(BinNumber, Len(BinNumber) - i)

Temp = HEXtoBin(Hex(CLng("H" BINtoHEX(CRC)) Xor CLng("H" Hex_CRC))) Temp

CRC = BINtoHEX(Temp)

If Len(Temp) = i Then

CRC = CRC(CRC, Hex_CRC, 0)

End If

End Function

Private Function HEXtoBin(Hex_Number) As String

'十六进制转换为二进制

Dim i As Long

Dim B As String

Hex_Number = UCase(Hex_Number)

For i = 1 To Len(Hex_Number)

Select Case Mid(Hex_Number, i, 1)

Case "0": B = B "0000"

Case "1": B = B "0001"

Case "2": B = B "0010"

Case "3": B = B "0011"

Case "4": B = B "0100"

Case "5": B = B "0101"

Case "6": B = B "0110"

Case "7": B = B "0111"

Case "8": B = B "1000"

Case "9": B = B "1001"

Case "A": B = B "1010"

Case "B": B = B "1011"

Case "C": B = B "1100"

Case "D": B = B "1101"

Case "E": B = B "1110"

Case "F": B = B "1111"

End Select

Next i

While Left(B, 1) = "0"

B = Right(B, Len(B) - 1)

Wend

HEXtoBin = B

End Function

Private Function BINtoHEX(ByVal Bin_Number As String) As String

'二进制转换为十六进制

Dim i As Long

Dim H As String

If Len(Bin_Number) Mod 4 0 Then

Bin_Number = String(4 - Len(Bin_Number) Mod 4, "0") Bin_Number

End If

For i = 1 To Len(Bin_Number) Step 4

Select Case Mid(Bin_Number, i, 4)

Case "0000": H = H "0"

Case "0001": H = H "1"

Case "0010": H = H "2"

Case "0011": H = H "3"

Case "0100": H = H "4"

Case "0101": H = H "5"

Case "0110": H = H "6"

Case "0111": H = H "7"

Case "1000": H = H "8"

Case "1001": H = H "9"

Case "1010": H = H "A"

Case "1011": H = H "B"

Case "1100": H = H "C"

Case "1101": H = H "D"

Case "1110": H = H "E"

Case "1111": H = H "F"

End Select

Next i

While Left(H, 1) = "0"

H = Right(H, Len(H) - 1)

Wend

BINtoHEX = H

End Function

相关问答

Q1: vb 如何校验文件的CRC 或者MD5或什么都行

就是收集boot.ini的不变的一些相关的信息（如文件大小，文件名等等），然后组成字符串，再用md5函数把组成的字符串编码。

以后就用这个编码进行校验了，字符串比较（compare即可）。

不过对boot.ini文件校验没有多大的意义，随便装一个什么dos工具箱或者用优化软件优化以下那个校验码准变。

Q2: vb，crc校验的程序

'Text1.Text 输入数据

'Text2.Text 输出数据

Dim ReturnData(1) As Byte

Private Sub Command1_Click()

Dim CRC(2) As Byte

Dim d(6) As Byte '待传输数据

ReDim data(7) As Byte

For i = 0 To 5

data(i) = "h" + Mid(Text1.Text, 2 * i + 1, 2)

Debug.Print data(i)

Next i

Call CRC16(data, UBound(data) - 2, data(6), data(7)) '调用CRC16计算函数

' CRC(0)为高位

' CRC(1)为低位

End Sub

Function CRC16(data() As Byte, i As Integer, ByRef ReturnDatalo As Byte, ByRef ReturnDatahi As Byte) As String

Dim CRC16Lo As Byte, CRC16Hi As Byte 'CRC寄存器

Dim CL As Byte, CH As Byte '多项式码HA001

Dim SaveHi As Byte, SaveLo As Byte

Dim Flag As Integer

CRC16Lo = HFF

CRC16Hi = HFF

CL = H1

CH = HA0

For i = 0 To UBound(data) - 2

CRC16Lo = CRC16Lo Xor data(i) '每一个数据与CRC寄存器进行异或

For Flag = 0 To 9

SaveHi = CRC16Hi

SaveLo = CRC16Lo

CRC16Hi = CRC16Hi \ 2 '高位右移一位

CRC16Lo = CRC16Lo \ 2 '低位右移一位

If ((SaveHi And H1) = H1) Then '如果高位字节最后一位为1

CRC16Lo = CRC16Lo Or H80 '则低位字节右移后前面补1

End If '否则自动补0

If ((SaveLo And H1) = H1) Then '如果LSB为1，则与多项式码进行异或

CRC16Hi = CRC16Hi Xor CH

CRC16Lo = CRC16Lo Xor CL

End If

Next Flag

Next i

ReturnDatahi = CRC16Hi 'CRC高位

ReturnDatalo = CRC16Lo 'CRC低位

Debug.Print Hex(CRC16Lo), Hex(CRC16Hi)

Text2.Text = Text1.Text Hex(CRC16Lo) Hex(CRC16Hi)

End Function

Q3: VB CRC校验问题

大概看了下。有变量定义类型错误，修改如下：

Public

Function

crc16(ByRef

cmdstring()

As

Byte,

DataLen

As

Integer)

As

String

Dim

data

As

Integer

Dim

i

As

Integer

Dim

CRCHi

As

long,

CRCLo

As

long'这里应该定义为long.因为下面赋值是long型。朋友。

Dim

iIndex

As

Long

Dim

CRCStr

As

String

Dim

DataStr

As

String

CRCLo

=

HFF'看这里的赋值。long型

CRCHi

=

HFF

For

i

=

To

DataLen

iIndex

=

CRCLo

Xor

cmdstring(i)

CRCLo

=

CRCHi

Xor

GetCRCLo(iIndex)

'低位处理

CRCHi

=

GetCRCHi(iIndex)

'高位处理

DataStr

=

DataStr

Chr(cmdstring(i))

Next

i

Dim

ReturnData(1)

As

Byte

ReturnData(1)

=

CRCHi

ReturnData(0)

=

CRCLo

CRCStr

=

StrConv(ReturnData,

vbUnicode)

crc16

=

DataStr

+

CRCStr

End

Function

Q4: vb crc冗余校验

计算法就是依据CRC校验码vb.netcrc检验的产生原理来设计程序。其优点是模块代码少，修改灵活，可移植性好。其缺点为计算量大。为vb.netcrc检验了便于理解，这里假定了三位数据，而多项式码为A001(hex)。

在窗体上放置一命令按钮Command1，并添加如下代码vb.netcrc检验：

Private Sub Command1_Click()

　Dim CRC() As Byte

　Dim d() As Byte '待传输数据

　ReDim d(2) As Byte

　d(0) = 123

　d(1) = 112

　d(2) = 135

　CRC = CRC16(d) '调用CRC16计算函数

　'CRC(0)为高位

　'CRC(1)为低位

End Sub

注意：在数据传输时CRC的低位可能在前，而高位在后。

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