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# How to convert hex to string?

 P: n/a Hi! I've made little code to convert string into hex string... Public ReadOnly Property ToHexString(ByVal text As String) As String Get Dim arrBytes As Integer() = CharsToBytes(text) Dim sb As StringBuilder = New StringBuilder For i As Integer = 0 To arrBytes.Length - 1 '// If it's a single digit, append a zero in front of it. If (Hex(arrBytes(i)).Length = 1) Then sb.Append("0" + Hex(arrBytes(i))) Else sb.Append(Hex(arrBytes(i))) End If Next Return sb.ToString() End Get End Property Private Function CharsToBytes(ByVal text As String) As Integer() Dim c As Char() = text.ToCharArray() Dim arrBytes As Integer() ReDim arrBytes(c.Length() - 1) For i As Integer = 0 To c.Length() - 1 arrBytes(i) = System.Convert.ToByte(c(i)) Next Return arrBytes End Function .... and it's working fine. For example my name "MIKA" will be "4D494B41" as hex string, but I don't find out how to do this opposite way? I mean how to get "MIKA" of "4D494B41" hex string. Other question: It's possible to change when using VB like... Asc(c(i)) -> System.Convert.ToByte(c(i)) .... is there also same kind of way for Hex()-function? -- Thanks in advance! Mika Nov 21 '05 #1
5 Replies

 P: n/a Mika M wrote: ... and it's working fine. For example my name "MIKA" will be "4D494B41" as hex string, but I don't find out how to do this opposite way? I mean how to get "MIKA" of "4D494B41" hex string. Here's one way to do it: \\\ Private Function DecodeHex(ByVal HexString As String) As String Dim thisChar As String Dim ascii As Integer Dim ret As String 'Keep going until we exhaust all the source string Do While Len(HexString) > 0 'Get the next two-digit hex number thisChar = HexString.Substring(0, 2) 'Remove this hex number from the source string HexString = HexString.Substring(2) 'Get the value in decimal of this hex number ascii = CInt(Val("&H" & thisChar)) 'Convert it to a character ret &= Chr(ascii) Loop 'All done Return ret End Function /// Call this with "4D494B41" as the HexString parameter value and it will return "MIKA". It works by using a handy feature of the Val() command. If you pass a number prefixed with "&H", it will treat that as a hex number when it parses it. So if you ask it for Val("&H10"), it will return 16. The code simply loops through each pair of characters (each 8-bit hex value) and decodes the value to a number. It then gets the ASCII character represented by this number. There's no validation or anything so you'll need to add that yourself if there's a chance of passing non-hex values to the function. Hope that helps, -- (O) e n o n e Nov 21 '05 #2

 P: n/a Here's a shortened version of part of your existing code: You will notice that {0:X2} makes sure you always have 2 chars & you won't need to add your zero to the beginning Public Function ToHexString(ByVal sText As String) As String Dim arrBytes As Integer() = CharsToBytes(sText) Dim sb As StringBuilder = New StringBuilder For i As Integer = 0 To arrBytes.Length - 1 sb.Append(String.Format("{0:x2}", Hex(arrBytes(i)))) Next Return sb.ToString() End Function Crouchie1998 BA (HONS) MCP MCSE Nov 21 '05 #3

 P: n/a Mika, I have created two functions of my own which will be better for you. The zipped project is also attached if you want to download it. Otherwise, follow thses instructions: 1) Create a new Windows application 2) Add a button 3) Add this import: Imports System.text 4) Now, paste in the following functions: Private Function EncodeHexString(ByVal sText As String) As String Dim intLength As Integer = sText.Length If (intLength = 0) Then Return "" Dim intCount As Integer = 0 Dim sb As New StringBuilder(intLength * 2) Dim bBytes() As Byte = System.Text.Encoding.ASCII.GetBytes(sText) For intCount = 0 To bBytes.Length - 1 sb.AppendFormat("{0:X2}", bBytes(intCount)) Next Return sb.ToString() End Function Private Function DecodeHexString(ByVal sText As String) As String Dim intLength As Integer = sText.Length If (intLength = 0) Then Return "" Dim intCount As Integer = 0 Dim sb As New StringBuilder(CType(intLength / 2, Integer)) Try For intCount = 0 To sText.Length - 1 Step 2 sb.Append(Convert.ToChar(Byte.Parse(sText.Substrin g(intCount, 2), Globalization.NumberStyles.HexNumber))) Next Catch ex As Exception Return "" End Try Return sb.ToString() End Function 5) Double-click button1 & paste in this code: Dim strMika As String = "Mika" Dim strEncodedMika As String = EncodeHexString(strMika) MessageBox.Show(strEncodedMika) Dim strDecodedMika As String = DecodeHexString(strEncodedMika) MessageBox.Show(strDecodedMika) I hope this helps Crouchie1998 BA (HONS) MCP MCSE Nov 21 '05 #4

 P: n/a Thank You Crouchie!!! Your code was easy to understand and very useful in my case! -- Mika Nov 21 '05 #5

 P: n/a Not sure if this is the most elegent solution but if you still need one try this... Dim S as String = HexAsStringToCharactersAsString("4D494B41") S should now contain "MIKA" Private Function HexAsStringToCharactersAsString(ByVal HexString As String) As String 'we`re assuming HexString passed is formatted as 2 chars for each individual Hex value 'ie A = 0A, B=0B Dim UB As Integer = HexString.Length - 1 Dim SB As New StringBuilder For Idx As Integer = 0 To UB Step 2 SB.Append(Microsoft.VisualBasic.ChrW(System.Conver t.ToInt32(HexString.Chars(Idx) & HexString.Chars(Idx + 1), 16))) Next Return SB.ToString End Function "Mika M" wrote in message news:O%****************@tk2msftngp13.phx.gbl... Hi! I've made little code to convert string into hex string... Public ReadOnly Property ToHexString(ByVal text As String) As String Get Dim arrBytes As Integer() = CharsToBytes(text) Dim sb As StringBuilder = New StringBuilder For i As Integer = 0 To arrBytes.Length - 1 '// If it's a single digit, append a zero in front of it. If (Hex(arrBytes(i)).Length = 1) Then sb.Append("0" + Hex(arrBytes(i))) Else sb.Append(Hex(arrBytes(i))) End If Next Return sb.ToString() End Get End Property Private Function CharsToBytes(ByVal text As String) As Integer() Dim c As Char() = text.ToCharArray() Dim arrBytes As Integer() ReDim arrBytes(c.Length() - 1) For i As Integer = 0 To c.Length() - 1 arrBytes(i) = System.Convert.ToByte(c(i)) Next Return arrBytes End Function ... and it's working fine. For example my name "MIKA" will be "4D494B41" as hex string, but I don't find out how to do this opposite way? I mean how to get "MIKA" of "4D494B41" hex string. Other question: It's possible to change when using VB like... Asc(c(i)) -> System.Convert.ToByte(c(i)) ... is there also same kind of way for Hex()-function? -- Thanks in advance! Mika Nov 21 '05 #6

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