如何将字节数组转换为十六进制字符串,反之亦然?


当前回答

具有扩展支持的基本解决方案

public static class Utils
{
    public static byte[] ToBin(this string hex)
    {
        int NumberChars = hex.Length;
        byte[] bytes = new byte[NumberChars / 2];
        for (int i = 0; i < NumberChars; i += 2)
            bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
        return bytes;
    }
    public static string ToHex(this byte[] ba)
    {
        return  BitConverter.ToString(ba).Replace("-", "");
    }
}

并像下面那样使用这个类

    byte[] arr1 = new byte[] { 1, 2, 3 };
    string hex1 = arr1.ToHex();
    byte[] arr2 = hex1.ToBin();

其他回答

另一种基于查找表的方法。该方法只为每个字节使用一个查找表,而不是为每个半字节使用查找表。

private static readonly uint[] _lookup32 = CreateLookup32();

private static uint[] CreateLookup32()
{
    var result = new uint[256];
    for (int i = 0; i < 256; i++)
    {
        string s=i.ToString("X2");
        result[i] = ((uint)s[0]) + ((uint)s[1] << 16);
    }
    return result;
}

private static string ByteArrayToHexViaLookup32(byte[] bytes)
{
    var lookup32 = _lookup32;
    var result = new char[bytes.Length * 2];
    for (int i = 0; i < bytes.Length; i++)
    {
        var val = lookup32[bytes[i]];
        result[2*i] = (char)val;
        result[2*i + 1] = (char) (val >> 16);
    }
    return new string(result);
}

我还使用查找表中的ushort、struct{char X1,X2}、struct{byte X1,X2}测试了这个变体。

根据编译目标(x86、X64)的不同,它们要么具有大致相同的性能,要么稍慢于此变体。


为了获得更高的性能,其不安全的兄弟:

private static readonly uint[] _lookup32Unsafe = CreateLookup32Unsafe();
private static readonly uint* _lookup32UnsafeP = (uint*)GCHandle.Alloc(_lookup32Unsafe,GCHandleType.Pinned).AddrOfPinnedObject();

private static uint[] CreateLookup32Unsafe()
{
    var result = new uint[256];
    for (int i = 0; i < 256; i++)
    {
        string s=i.ToString("X2");
        if(BitConverter.IsLittleEndian)
            result[i] = ((uint)s[0]) + ((uint)s[1] << 16);
        else
            result[i] = ((uint)s[1]) + ((uint)s[0] << 16);
    }
    return result;
}

public static string ByteArrayToHexViaLookup32Unsafe(byte[] bytes)
{
    var lookupP = _lookup32UnsafeP;
    var result = new char[bytes.Length * 2];
    fixed(byte* bytesP = bytes)
    fixed (char* resultP = result)
    {
        uint* resultP2 = (uint*)resultP;
        for (int i = 0; i < bytes.Length; i++)
        {
            resultP2[i] = lookupP[bytesP[i]];
        }
    }
    return new string(result);
}

或者如果您认为可以直接写入字符串:

public static string ByteArrayToHexViaLookup32UnsafeDirect(byte[] bytes)
{
    var lookupP = _lookup32UnsafeP;
    var result = new string((char)0, bytes.Length * 2);
    fixed (byte* bytesP = bytes)
    fixed (char* resultP = result)
    {
        uint* resultP2 = (uint*)resultP;
        for (int i = 0; i < bytes.Length; i++)
        {
            resultP2[i] = lookupP[bytesP[i]];
        }
    }
    return result;
}

对老年人来说最快的方法。。。想念你的指针

    static public byte[] HexStrToByteArray(string str)
    {
        byte[] res = new byte[(str.Length % 2 != 0 ? 0 : str.Length / 2)]; //check and allocate memory
        for (int i = 0, j = 0; j < res.Length; i += 2, j++) //convert loop
            res[j] = (byte)((str[i] % 32 + 9) % 25 * 16 + (str[i + 1] % 32 + 9) % 25);
        return res;
    }

可以使用从.NET 5开始的Convert.ToHexString。还有一个用于反向操作的方法:Convert.FromHexString。


对于较旧版本的.NET,您可以使用:

public static string ByteArrayToString(byte[] ba)
{
  StringBuilder hex = new StringBuilder(ba.Length * 2);
  foreach (byte b in ba)
    hex.AppendFormat("{0:x2}", b);
  return hex.ToString();
}

or:

public static string ByteArrayToString(byte[] ba)
{
  return BitConverter.ToString(ba).Replace("-","");
}

举个例子,这里有更多的方法。

反向转换如下:

public static byte[] StringToByteArray(String hex)
{
  int NumberChars = hex.Length;
  byte[] bytes = new byte[NumberChars / 2];
  for (int i = 0; i < NumberChars; i += 2)
    bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
  return bytes;
}

使用Substring是与Convert.ToByte结合使用的最佳选项。有关详细信息,请参阅此答案。如果需要更好的性能,必须避免Convert.ToByte,然后才能删除SubString。

还有XmlWriter.WriteBinHex(请参见MSDN页面)。如果需要将十六进制字符串放入XML流中,这非常有用。

下面是一个独立的方法来了解它的工作原理:

    public static string ToBinHex(byte[] bytes)
    {
        XmlWriterSettings xmlWriterSettings = new XmlWriterSettings();
        xmlWriterSettings.ConformanceLevel = ConformanceLevel.Fragment;
        xmlWriterSettings.CheckCharacters = false;
        xmlWriterSettings.Encoding = ASCIIEncoding.ASCII;
        MemoryStream memoryStream = new MemoryStream();
        using (XmlWriter xmlWriter = XmlWriter.Create(memoryStream, xmlWriterSettings))
        {
            xmlWriter.WriteBinHex(bytes, 0, bytes.Length);
        }
        return Encoding.ASCII.GetString(memoryStream.ToArray());
    }

有一个名为SoapHexBinary的类,它完全符合您的需要。

using System.Runtime.Remoting.Metadata.W3cXsd2001;

public static byte[] GetStringToBytes(string value)
{
    SoapHexBinary shb = SoapHexBinary.Parse(value);
    return shb.Value;
}

public static string GetBytesToString(byte[] value)
{
    SoapHexBinary shb = new SoapHexBinary(value);
    return shb.ToString();
}