在 C # 中将 string 转换为十六进制 string

First you'll need to get it into a byte[], so do this:

byte[] ba = Encoding.Default.GetBytes("sample");

and then you can get the string:

var hexString = BitConverter.ToString(ba);

now, that's going to return a string with dashes (-) in it so you can then simply use this:

hexString = hexString.Replace("-", "");

to get rid of those if you want.

NOTE: you could use a different Encoding if you needed to.

var result = string.Join("", input.Select(c => ((int)c).ToString("X2")));

OR

var result  =string.Join("",
input.Select(c=> String.Format("{0:X2}", Convert.ToInt32(c))));

According to this snippet here, this approach should be good for long strings:

private string StringToHex(string hexstring)
{
StringBuilder sb = new StringBuilder();
foreach (char t in hexstring)
{
//Note: X for upper, x for lower case letters
sb.Append(Convert.ToInt32(t).ToString("x2"));
}
return sb.ToString();
}

usage:

string result = StringToHex("Hello world"); //returns "48656c6c6f20776f726c64"

Another approach in one line

string input = "Hello world";
string result = String.Concat(input.Select(x => ((int)x).ToString("x2")));

For Unicode support:

public class HexadecimalEncoding
{
public static string ToHexString(string str)
{
var sb = new StringBuilder();


var bytes = Encoding.Unicode.GetBytes(str);
foreach (var t in bytes)
{
sb.Append(t.ToString("X2"));
}


return sb.ToString(); // returns: "48656C6C6F20776F726C64" for "Hello world"
}


public static string FromHexString(string hexString)
{
var bytes = new byte[hexString.Length / 2];
for (var i = 0; i < bytes.Length; i++)
{
bytes[i] = Convert.ToByte(hexString.Substring(i * 2, 2), 16);
}


return Encoding.Unicode.GetString(bytes); // returns: "Hello world" for "48656C6C6F20776F726C64"
}
}

few Unicode alternatives

var s = "0𝟏𝟚𝟥𝟰𝟻";


var s1 = string.Concat(s.Select(c => $"{(int)c:x4}"));  // left padded with 0 - "0030d835dfcfd835dfdad835dfe5d835dff0d835dffb"


var sL = BitConverter.ToString(Encoding.Unicode.GetBytes(s)).Replace("-", "");       // Little Endian "300035D8CFDF35D8DADF35D8E5DF35D8F0DF35D8FBDF"
var sB = BitConverter.ToString(Encoding.BigEndianUnicode.GetBytes(s)).Replace("-", ""); // Big Endian "0030D835DFCFD835DFDAD835DFE5D835DFF0D835DFFB"


// no encodding "300035D8CFDF35D8DADF35D8E5DF35D8F0DF35D8FBDF"
byte[] b = new byte[s.Length * sizeof(char)];
Buffer.BlockCopy(s.ToCharArray(), 0, b, 0, b.Length);
var sb = BitConverter.ToString(b).Replace("-", "");

In .NET 5.0 and later you can use the Convert.ToHexString() method.

using System;
using System.Text;


string value = "Hello world";


byte[] bytes = Encoding.UTF8.GetBytes(value);


string hexString = Convert.ToHexString(bytes);


Console.WriteLine($"String value: \"{value}\"");
Console.WriteLine($"   Hex value: \"{hexString}\"");

Running the above example code, you would get the following output:

String value: "Hello world"
Hex value: "48656C6C6F20776F726C64"

In case detailed conversion with regard to endianness of bytes or words is required, here is an example of the craft to do bitwise conversion.

var bcd = new byte[] { 64, 7, 19, 0, 0, 0 };
var str = String.Join("", bcd.Reverse().Select(b => $"{b:X2}"));

str => 000000317004

To also swap 4-bit nibbles of each byte, shift and mask to format each 4 bit separately.

var bcd = new byte[] { 64, 7, 19, 0, 0, 0 };
var str = String.Join("", bcd.Reverse().Select(b => $"{b & 0x0F:X1}{b>>4:X1}"));

str => 000000130740