我从sql server复制并粘贴了这个二进制数据，我现在无法查询。
0xBAC893CAB8B7FE03C927417A2A3F6A60BD30FF35E250011CB25507EBFCD5223B
如何将其转换回c＃中的字节数组？
答案 0 :(得分：21)
这样的事情：
using System;
public static class Parser
{
static void Main()
{
string hex = "0xBAC893CAB8B7FE03C927417A2A3F6A6"
+ "0BD30FF35E250011CB25507EBFCD5223B";
byte[] parsed = ParseHex(hex);
// Just for confirmation...
Console.WriteLine(BitConverter.ToString(parsed));
}
public static byte[] ParseHex(string hex)
{
int offset = hex.StartsWith("0x") ? 2 : 0;
if ((hex.Length % 2) != 0)
{
throw new ArgumentException("Invalid length: " + hex.Length);
}
byte[] ret = new byte[(hex.Length-offset)/2];
for (int i=0; i < ret.Length; i++)
{
ret[i] = (byte) ((ParseNybble(hex[offset]) << 4)
| ParseNybble(hex[offset+1]));
offset += 2;
}
return ret;
}
static int ParseNybble(char c)
{
if (c >= '0' && c <= '9')
{
return c-'0';
}
if (c >= 'A' && c <= 'F')
{
return c-'A'+10;
}
if (c >= 'a' && c <= 'f')
{
return c-'a'+10;
}
throw new ArgumentException("Invalid hex digit: " + c);
}
}
（编辑：现在效率稍高 - 不需要子串......）
ParseNybble可能更有效率。例如，交换机/案例可能更有效：
static int ParseNybble(char c)
{
switch (c)
{
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
return c-'0';
case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
return c-'A'+10;
case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
return c-'a'+10;
}
throw new ArgumentException("Invalid hex digit: " + c);
}
或可能是查找数组：
// Omitted for brevity... I'm sure you get the gist
private static readonly int[] NybbleLookup = BuildLookup();
private int ParseNybble(char c)
{
if (c > 'f')
{
throw new ArgumentException("Invalid hex digit: " + c);
}
int ret = NybbleLookup[c];
if (ret == -1)
{
throw new ArgumentException("Invalid hex digit: " + c);
}
return ret;
}
我没有对这些中的任何一个进行基准测试，我不知道哪个是最快的。目前的解决方案可能是最简单的。
答案 1 :(得分：7)
考虑利用已经公开执行十六进制转换的Framework类，例如XmlReader：
public static byte[] HexToBytes(this string hexEncodedBytes, int start, int end)
{
int length = end - start;
const string tagName = "hex";
string fakeXmlDocument = String.Format("<{1}>{0}</{1}>",
hexEncodedBytes.Substring(start, length),
tagName);
var stream = new MemoryStream(Encoding.ASCII.GetBytes(fakeXmlDocument));
XmlReader reader = XmlReader.Create(stream, new XmlReaderSettings());
int hexLength = length / 2;
byte[] result = new byte[hexLength];
reader.ReadStartElement(tagName);
reader.ReadContentAsBinHex(result, 0, hexLength);
return result;
}
用法：
string input = "0xBAC893CAB8B7FE03C927417A2A3F6A60BD30FF35E250011CB255";
byte[] bytes = input.HexToBytes(2, input.Length);
答案 2 :(得分：3)
简单：
string hexnum = "0000000F"; // Represents 15
int value = int.Parse(hexnum, System.Globalization.NumberStyles.HexNumber);
你要记住要做的就是用int将十六进制数分成8个十六进制数字的组（十六进制是每个4位，CLR int类型是32位，因此每个int有8位数）。还有一个byte.Parse（），它的工作方式相同，但一次传入两个十六进制数字。
答案 3 :(得分：3)
这样的事情：
public byte[] ParseHexString(string text)
{
if ((text.Length % 2) != 0)
{
throw new ArgumentException("Invalid length: " + text.Length);
}
if (text.StartsWith("0x", StringComparison.InvariantCultureIgnoreCase))
{
text = text.Substring(2);
}
int arrayLength = text.Length / 2;
byte[] byteArray = new byte[arrayLength];
for (int i = 0; i < arrayLength; i++)
{
byteArray[i] = byte.Parse(text.Substring(i*2, 2), NumberStyles.HexNumber);
}
return byteArray;
}
答案 4 :(得分：1)
您需要稍微修改一下（例如，跳过前两个字符），但它会处理字符串中的空格：
/// <summary>
/// Decodes a hex string, ignoring all non-hex characters, and stores
/// the decodes series of bytes into the shared buffer. This returns
/// the number of bytes that were decoded.
/// <para>Hex characters are [0-9, a-f, A-F].</para>
/// </summary>
/// <param name="hexString">String to parse into bytes.</param>
/// <param name="buffer">Buffer into which to store the decoded binary data.</param>
/// <returns>The number of bytes decoded.</returns>
private static int DecodeHexIntoBuffer(string hexString, byte[] buffer)
{
int count = 0;
bool haveFirst = false;
bool haveSecond = false;
char first = '0';
char second = '0';
for (int i = 0; i < hexString.Length; i++)
{
if (!haveFirst)
{
first = hexString[i];
haveFirst = char.IsLetterOrDigit(first);
// we have to continue to the next iteration
// or we will miss characters
continue;
}
if (!haveSecond)
{
second = hexString[i];
haveSecond = char.IsLetterOrDigit(second);
}
if (haveFirst && haveSecond)
{
string hex = "" + first + second;
byte nextByte;
if (byte.TryParse(hex, NumberStyles.HexNumber, null, out nextByte))
{
// store the decoded byte into the next slot of the buffer
buffer[count++] = nextByte;
}
// reset the flags
haveFirst = haveSecond = false;
}
}
return count;
}
答案 5 :(得分：1)
慢而有趣的方式：D
public static byte[] StringToByteArray(string hex)
{
hex = hex.Replace(" ", "");
hex = hex.Replace(":", "");
return Enumerable.Range(0, hex.Length)
.Where(x => x % 2 == 0)
.Select(x => Convert.ToByte(hex.Substring(x, 2), 16))
.ToArray();
}
-JD
答案 6 :(得分：0)
实际上，有一种更简单的方法可以将两个字符一次转换为一个字节：
/// <summary>
/// This will convert a hex-encoded string to byte data
/// </summary>
/// <param name="hexData">The hex-encoded string to convert</param>
/// <returns>The bytes that make up the hex string</returns>
public static byte[] FromHex(string hexData)
{
List<byte> data = new List<byte>();
string byteSet = string.Empty;
int stringLen = hexData.Length;
int length = 0;
for (int i = 0; i < stringLen; i = i + 2)
{
length = (stringLen - i) > 1 ? 2 : 1;
byteSet = hexData.Substring(i, length);
// try and parse the data
data.Add(Convert.ToByte(byteSet, 16 /*base*/));
} // next set
return data.ToArray();
}
答案 7 :(得分：0)
我将它用于C＃，来自Java中的类似代码。
private static char[] hexdigit = "0123456789abcdef".ToCharArray();
public static string hexlify(string argbuf) {
int arglen = argbuf.Length;
char[] argca = argbuf.ToCharArray ();
StringBuilder retbuf = new StringBuilder(arglen * 2);
for (int i = 0; i < arglen; i++) {
char ch = argca[i];
retbuf.Append(hexdigit[(ch >> 4) & 0xF]);
retbuf.Append(hexdigit[ch & 0xF]);
}
return retbuf.ToString();
}
public static string unhexlify(string argbuf) {
int arglen = argbuf.Length;
if (arglen % 2 != 0) {
throw new ArgumentOutOfRangeException ("Odd-length string");
}
char[] argca = argbuf.ToCharArray ();
StringBuilder retbuf = new StringBuilder(arglen / 2);
for (int i = 0; i < arglen; i += 2) {
int top = Convert.ToInt32 (argca[i].ToString (), 16);
int bot = Convert.ToInt32 (argca[i + 1].ToString (), 16);
if (top == -1 || bot == -1) {
throw new ArgumentOutOfRangeException ("Non-hexadecimal digit found");
}
retbuf.Append((char) ((top << 4) + bot));
}
return retbuf.ToString();
}
答案 8 :(得分：0)
也许这个很可爱！
string source = "Hello World!";
using (SHA256 sha256Hash = SHA256.Create())
{
//From String to byte array
byte[] sourceBytes = Encoding.UTF8.GetBytes(source);
byte[] hashBytes = sha256Hash.ComputeHash(sourceBytes);
string hash = BitConverter.ToString(hashBytes).Replace("-", String.Empty);
Console.WriteLine("The SHA256 hash of " + source + " is: " + hash);
}