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Replace() working with hex value

I would like to use the Replace() method but using hex values instead of string value.
I have a programm in C# who write text file.
I don't know why, but when the programm write the '°' (-> Number) it's wrotten ° ( in hex : C2 B0 instead of B0).
I just would like to patch it, in order to corect this.
Is it possible to do re place in order to replace C2B0 by B0 ? How doing this ?
Thanks a lot :)

Not sure if this is the best solution for your problem but if you want a replace function for a string using hex values this will work:
var newString = HexReplace(sourceString, "C2B0", "B0");
private static string HexReplace(string source, string search, string replaceWith) {
var realSearch = string.Empty;
var realReplace = string.Empty;
if(search.Length % 2 == 1) throw new Exception("Search parameter incorrect!");
for (var i = 0; i < search.Length / 2; i++) {
var hex = search.Substring(i * 2, 2);
realSearch += (char)int.Parse(hex, System.Globalization.NumberStyles.HexNumber);
}
for (var i = 0; i < replaceWith.Length / 2; i++) {
var hex = replaceWith.Substring(i * 2, 2);
realReplace += (char)int.Parse(hex, System.Globalization.NumberStyles.HexNumber);
}
return source.Replace(realSearch, realReplace);
}

C# strings are Unicode. When they are written to a file, an encoding must be applied. The default encoding used by File.WriteAllText is utf-8 with no byte order mark.
The two-byte sequence 0xC2B0 is the representation of the ° degree sign U+00B0 codepoint in utf-8.
To get rid of the 0xC2 part, apply a different encoding, for example latin-1:
var latin1 = Encoding.GetEncoding(1252);
File.WriteAllText(path, text, latin1);
To address the "hex replace" idea of the question: Best practice to remove the utf-8 leading byte from existing files would be to do a ReadAllText with utf-8, followed by a WriteAllText as shown above (or stream chunking if the files are too big to read to memory as a whole).
Single-byte character encodings cannot represent all Unicode characters, so substitution will happen for any such character in your DataTable.
The rendition as ° must be blamed on the viewer/editor you are using to display the file.
Further reading: https://stackoverflow.com/a/17269952/1132334

Converting long hex string to binary string throws OverflowException

Trying to convert a huge hex string to a binary string, but the OverflowException keeps gets thrown. This is my code to convert an image file to a hex string (which when used with a FlowDocument works perfectly!):
string h = new System.Runtime.Remoting.Metadata.W3cXsd2001.SoapHexBinary(System.IO.File.ReadAllBytes(Path)).ToString();
Now, however, I want to take this hex string and convert it to a binary string so that it may also displayed in FlowDocument. First, I tried writing it to a temp text file and then attempt to read it into a byte array:
string TempPath = System.IO.Path.Combine(System.IO.Path.GetTempPath(), "Text.txt");
using (System.IO.StreamWriter sw = new System.IO.StreamWriter(TempPath))
{
sw.WriteLine(Convert.ToString(Convert.ToInt64(h, 16), 2).PadLeft(12, '0'));
}
byte[] c = System.IO.File.ReadAllBytes(TempPath);
When that didn't work, I tried reading it into a string:
string c = System.IO.File.ReadAll(TempPath);
Neither worked and still throw OverflowException. I have also tried just doing this and skipped writing to a file altogether:
string s = Convert.ToString(Convert.ToInt64(h, 16), 2).PadLeft(12, '0')
And despite what approach I take, I still get an exception thrown. How are large strings like this normally handled?
Update
I've modified my algorithm to convert one character at a time, so now it looks like this:
string NewBinary = "";
try
{
int i = 0;
foreach (char c in h)
{
if (i == 100) break;
NewBinary = string.Concat(NewBinary, Convert.ToString(Convert.ToInt64(c.ToString(), 16), 2).PadLeft(12, '0'));
i++;
}
}
The problem with this is that the string is always going to be super long and the code above takes a LONG time to generate the binary string. I limited the length to 100 to test conversion, so the conversion itself is not an issue.

An int64 is represented by a 16 character hex string, which is why attempting to convert a "huge string" causes an OverflowException - the value is more than can be represented by an int64. You will need to break the string up into groups of max 16 chars & convert those to binary & concatenate them.

You could convert a nibble at a time using a lookup array, for example:
public static string HexStringToBinaryString(string hexString)
{
var result = new StringBuilder();
string[] lookup =
{
"0000", "0001", "0010", "0011",
"0100", "0101", "0110", "0111",
"1000", "1001", "1010", "1011",
"1100", "1101", "1110", "1111"
};
foreach (char nibble in hexString.Select(char.ToUpper))
result.Append((nibble > '9') ? lookup[10+nibble-'A'] : lookup[nibble-'0']);
return result.ToString();
}

Convert each hex character of the string into its corresponding binary pattern (eg A becomes 1010 etc)

UTF16 string to normal text

I have one column in DB containing UTF16 string and I want to convert the UTF16 string into normal text. How to achieve this in c# ?
For example :
Source : 0645 0631 062D 0628 0627 0020 0627 0644 0639 0627 0644 0645
Convert : مرحبا العالم

I presume that source is simply a string containing the byte values, as this is one thing not quite clear from your question.
You first need to turn that into a byte array. Of course you first need to remove the blanks.
// Initialize the byte array
string sourceNoBlanks = source.Replace(" ", "").Trim();
if ((sourceNoBlanks.Length % 2) > 0)
throw new ArgumentException("The length of the source string must be a multiple of 2!");
byte[] sourceBytes = new byte[source.Length / 2];
// Then, create the bytes
for (int i = 0; i < sourceBytes.Length; i++)
{
string byteString = sourceNoBlanks.Substring(i*2, 2);
sourceBytes[i] = Byte.Parse(byteString, NumberStyles.HexNumber);
}
After that you can easily convert it to string:
string result = Encoding.UTF32.GetString(sourceBytes);
I suggest you read up on the UTF32 encoding to understand little/big endian encoding.

convert hex to byte without conversion

I have a very specific requirement. I have some data. Of which, strings and spaces are to be converted to EBCDIC while numbers to Hexadecimal.
For Example, my string is "Test123"
Test => EBCDIC
123 => Hexadecimal.
What I am trying to do is check every character in string if its number or not, and then based on that doing my conversion.
byte[] dataBuffer = new byte[length];
int i = 0;
if (toEBCDIC)
{
foreach (char c in data)
{
byte[] temp = new byte[1];
if (Char.IsNumber(c))
{
string hexValue = Convert.ToInt32(c).ToString("X");
temp = Encoding.ASCII.GetBytes(hexValue);
dataBuffer[i] = temp[0];
}
else
{
temp = Encoding.GetEncoding("IBM01140").GetBytes(c.ToString());
dataBuffer[i] = temp[0];
}
i++;
}
dataBuffer.CopyTo(array, byteIndex);
The problem comes when i try to convert the number. I need to keep my output in byte array, as i have to write the output to a memory stream and then to a file.
When i get the hex value of number, and then try to convert it to byte, actual conversion happens.
For "1", hexvalue = 31.
Now I want to keep this 31 unchanged in bytes. I mean to say that, when i write it to byte array, it should remain 31 only. But when do GetBytes, it makes byte array, converting 3 and 1 separately to bytes.
Can anyone please help me on this..!!

The problem is here:
ToString("X")
Now it's a hexadecimal string. So in your example, from this point onward, the 3 and the 1 have become separated.
How to fix this: don't convert.
if (Char.IsNumber(c))
{
dataBuffer[i] = (byte)c;
}
Not tested. I think that's what you want. At least, that's what you describe in the last paragraph. That wouldn't make the numbers hexadecimal though - it would make them ASCII, and it's a bit odd to be mixing that with EBCDIC.

You convert the char to its code and then convert that code to string. You don't have to do the second step, instead use the code directly:
if (Char.IsNumber(c))
{
byte hexValue = Convert.ToByte(c);
dataBuffer[i] = hexValue;
}

How can i convert a string of characters into binary string and back again?

I need to convert a string into it's binary equivilent and keep it in a string. Then return it back into it's ASCII equivalent.

You can encode a string into a byte-wise representation by using an Encoding, e.g. UTF-8:
var str = "Out of cheese error";
var bytes = Encoding.UTF8.GetBytes(str);
To get back a .NET string object:
var strAgain = Encoding.UTF8.GetString(bytes);
// str == strAgain
You seem to want the representation as a series of '1' and '0' characters; I'm not sure why you do, but that's possible too:
var binStr = string.Join("", bytes.Select(b => Convert.ToString(b, 2)));
Encodings take an abstract string (in the sense that they're an opaque representation of a series of Unicode code points), and map them into a concrete series of bytes. The bytes are meaningless (again, because they're opaque) without the encoding. But, with the encoding, they can be turned back into a string.
You seem to be mixing up "ASCII" with strings; ASCII is simply an encoding that deals only with code-points up to 128. If you have a string containing an 'é', for example, it has no ASCII representation, and so most definitely cannot be represented using a series of ASCII bytes, even though it can exist peacefully in a .NET string object.
See this article by Joel Spolsky for further reading.

You can use these functions for converting to binary and restore it back :
public static string BinaryToString(string data)
{
List<Byte> byteList = new List<Byte>();
for (int i = 0; i < data.Length; i += 8)
{
byteList.Add(Convert.ToByte(data.Substring(i, 8), 2));
}
return Encoding.ASCII.GetString(byteList.ToArray());
}
and for converting string to binary :
public static string StringToBinary(string data)
{
StringBuilder sb = new StringBuilder();
foreach (char c in data.ToCharArray())
{
sb.Append(Convert.ToString(c, 2).PadLeft(8, '0'));
}
return sb.ToString();
}
Hope Helps You.

First convert the string into bytes, as described in my comment and in Cameron's answer; then iterate, convert each byte into an 8-digit binary number (possibly with Convert.ToString, padding appropriately), then concatenate. For the reverse direction, split by 8 characters, run through Convert.ToInt16, build up a byte array, then convert back to a string with GetString.