C# 16进制字节转Int（涉及：Base64转byte数组）
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一个字节数组，如下：
List<byte> by2 = new List<byte>() {0x55,0x22 };//8789
其对应的十进制的值为：8789
从上图可知，C#中byte数组默认为低字节在前
再例如：
List<byte> by3 = new List<byte>() { 0x55, 0x22 ,0x11};//1122901
对应的十进制是：1122901
对应的16进制为：0x112255，如下：
经过上述两个案例，C#byte数组中是按照低字节在前的方式排列的。
C#中有什么方法转化字节流为Int吗？
List<byte> by2 = new List<byte>() {0x55,0x22 };//8789 int ResultInt16 = BitConverter.ToInt16(by2.ToArray(), 0); List<byte> by4 = new List<byte>() { 0x55, 0x22, 0x11, 0x01 };//1428295937 int ResultInt32 = BitConverter.ToInt32(by4.ToArray(), 0);
涉及到两个方法：BitConverter.ToInt16 和 BitConverter.ToInt32
但是：：BitConverter.ToInt这个方法只能转化长度为2或者长度为4的字节数组，如果字节长度为3，则无法转化。
譬如：
List<byte> by3 = new List<byte>() { 0x55, 0x22 ,0x11};//1122901
因此，有必要做一个通用方法
在实际业务需求中，软硬件双方制定的通讯协议中经常为字节流指定是高字节在前？还是低字节在前？
因此，我总结的方法如下：
#region C# 字节转Int public static int GetValue(byte by) { return Convert.ToInt32(by); } #region 16进制转十进制 高字节在前 /// <summary> /// 16进制转十进制 高字节在前 /// </summary> /// <param name="Ary"></param> /// <returns></returns> public static int GetValue(List<byte> Ary) { double result = 0; var cm = 0; cm = Ary.Count; foreach (var item in Ary) { if (cm - 1 == 0) { result += item; } else { result += item * Math.Pow(16, (cm * 2 - 2)); cm--; } } return Convert.ToInt32(result); } /// <summary> /// 高字节在前 /// </summary> /// <param name="Ary"></param> /// <returns></returns> public static int GetValue(IEnumerable<byte> Ary) { double result = 0; var cm = 0; cm = Ary.Count(); foreach (var item in Ary) { if (cm - 1 == 0) { result += item; } else { result += item * Math.Pow(16, (cm * 2 - 2)); cm--; } } return Convert.ToInt32(result); } /// <summary> /// 16进制转十进制 具体参考十六进制的数值 /// </summary> /// <param name="Ary"></param> /// <returns></returns> public static int GetValue(List<int> Ary) { double result = 0; var cm = 0; cm = Ary.Count; foreach (var item in Ary) { if (cm - 1 == 0) { result += item; } else { result += item * Math.Pow(16, (cm * 2 - 2)); cm--; } } return Convert.ToInt32(result); } /// <summary> /// 16进制转十进制 /// </summary> /// <param name="Ary"></param> /// <returns></returns> public static int GetValue(IEnumerable<int> Ary) { double result = 0; var cm = 0; cm = Ary.Count(); foreach (var item in Ary) { if (cm - 1 == 0) { result += item; } else { result += item * Math.Pow(16, (cm * 2 - 2)); cm--; } } return Convert.ToInt32(result); } #endregion #region 16进制转十进制 低字节在前 /// <summary> /// 16进制转十进制 高字节在前 /// </summary> /// <param name="Ary"></param> /// <returns></returns> public static int GetValueLH(List<byte> Ary) { Ary.Reverse(); double result = 0; var cm = 0; cm = Ary.Count; foreach (var item in Ary) { if (cm - 1 == 0) { result += item; } else { result += item * Math.Pow(16, (cm * 2 - 2)); cm--; } } return Convert.ToInt32(result); } /// <summary> /// 低字节在前 /// </summary> /// <param name="Ary"></param> /// <returns></returns> public static int GetValueLH(IEnumerable<byte> Ary) { Ary.Reverse(); double result = 0; var cm = 0; cm = Ary.Count(); foreach (var item in Ary) { if (cm - 1 == 0) { result += item; } else { result += item * Math.Pow(16, (cm * 2 - 2)); cm--; } } return Convert.ToInt32(result); } /// <summary> /// 16进制转十进制 低字节在前 /// </summary> /// <param name="Ary"></param> /// <returns></returns> public static int GetValueLH(List<int> Ary) { Ary.Reverse(); double result = 0; var cm = 0; cm = Ary.Count; foreach (var item in Ary) { if (cm - 1 == 0) { result += item; } else { result += item * Math.Pow(16, (cm * 2 - 2)); cm--; } } return Convert.ToInt32(result); } /// <summary> /// 16进制转十进制 低字节在前 /// </summary> /// <param name="Ary"></param> /// <returns></returns> public static int GetValueLH(IEnumerable<int> Ary) { Ary.Reverse(); double result = 0; var cm = 0; cm = Ary.Count(); foreach (var item in Ary) { if (cm - 1 == 0) { result += item; } else { result += item * Math.Pow(16, (cm * 2 - 2)); cm--; } } return Convert.ToInt32(result); } #endregion #endregion
扩展：int数值转字节：
var by4 = BitConverter.GetBytes(8888);//长度四字节 var by2 = BitConverter.GetBytes(Convert.ToUInt16(8888));//长度两字节
C# base64 转 byte[]
static void Main(string[] args) { string btinfo = @"MDAwMDAwMDAwMDAwMDAwMAHgAMgB7wAATjcBAXEBqAADAGEM7QzoR0UPDOkM6wzrDOkM6QzsDOwM7QzrDOgM6gzpDOoM6QzpAkdFAAAAAAANAQEBAQEBAAAAAAAAAAAAAAA="; var Bys = Encoding.Default.GetBytes(btinfo); var Bse64Bys = Convert.FromBase64String(btinfo); Console.WriteLine("普通byte数组，8位表示一个普通字符，长度为："+Bys.Length); Console.WriteLine("Base64byte数组，6位表示一个base64字符，长度为：" + Bse64Bys.Length); Console.ReadLine(); }
继续转发别人的一篇【2020-12-24】
C#中的Byte，String，Int，Hex之间的转换函数
转化字符串：aabb00000000001a160100000008313233343536373839303131323233330100ffff9775 为字节数组
整理转换方法：
public class BytesTranfer
{
/// <summary> Convert a string of hex digits (ex: E4 CA B2) to a byte array. </summary>
/// <param name="s"> The string containing the hex digits (with or without spaces). </param>
/// <returns> Returns an array of bytes. </returns>
public byte[] HexStringToByteArray(string s)
{
s = s.Replace(" ", "");
byte[] buffer = new byte[s.Length / 2];
for (int i = 0; i < s.Length; i += 2)
{
buffer[i / 2] = (byte)Convert.ToByte(s.Substring(i, 2), 16);
}
return buffer;
}
/// <summary> Converts an array of bytes into a formatted string of hex digits (ex: E4 CA B2)</summary>
/// <param name="data"> The array of bytes to be translated into a string of hex digits. </param>
/// <returns> Returns a well formatted string of hex digits with spacing. </returns>
public string ByteArrayToHexString(byte[] data)
{
StringBuilder sb = new StringBuilder(data.Length * 3);
foreach (byte b in data)
{
sb.Append(Convert.ToString(b, 16).PadLeft(2, '0').PadRight(3, ' '));
}
return sb.ToString().ToUpper();
}
/// <summary>
/// 将一条十六进制字符串转换为ASCII
/// </summary>
/// <param name="hexstring">一条十六进制字符串</param>
/// <returns>返回一条ASCII码</returns>
public static string HexStringToASCII(string hexstring)
{
byte[] bt = HexStringToBinary(hexstring);
string lin = "";
for (int i = 0; i < bt.Length; i++)
{
lin = lin + bt[i] + " ";
}
string[] ss = lin.Trim().Split(new char[] { ' ' });
char[] c = new char[ss.Length];
int a;
for (int i = 0; i < c.Length; i++)
{
a = Convert.ToInt32(ss[i]);
c[i] = Convert.ToChar(a);
}
string b = new string(c);
return b;
}
/**/
/// <summary>
/// 16进制字符串转换为二进制数组
/// </summary>
/// <param name="hexstring">用空格切割字符串</param>
/// <returns>返回一个二进制字符串</returns>
public static byte[] HexStringToBinary(string hexstring)
{
string[] tmpary = hexstring.Trim().Split(' ');
byte[] buff = new byte[tmpary.Length];
for (int i = 0; i < buff.Length; i++)
{
buff[i] = Convert.ToByte(tmpary[i], 16);
}
return buff;
}
/// <summary>
/// 将byte型转换为字符串
/// </summary>
/// <param name="arrInput">byte型数组</param>
/// <returns>目标字符串</returns>
private string ByteArrayToString(byte[] arrInput)
{
int i;
StringBuilder sOutput = new StringBuilder(arrInput.Length);
for (i = 0; i < arrInput.Length; i++)
{
sOutput.Append(arrInput[i].ToString("X2"));
}
//将此实例的值转换为System.String
return sOutput.ToString();
}
/// <summary>
/// 对接收到的数据进行解包（将接收到的byte型数组解包为Unicode字符串）
/// </summary>
/// <param name="recbytes">byte型数组</param>
/// <returns>Unicode编码的字符串</returns>
public string disPackage(byte[] recbytes)
{
string temp = "";
foreach (byte b in recbytes)
temp += b.ToString("X2") + " ";//ToString("X2") 为C#中的字符串格式控制符
return temp;
}
/**
* int转byte[]
* 该方法将一个int类型的数据转换为byte[]形式，因为int为32bit，而byte为8bit所以在进行类型转换时，知会获取低8位，
* 丢弃高24位。通过位移的方式，将32bit的数据转换成4个8bit的数据。注意 &0xff，在这当中，&0xff简单理解为一把剪刀，
* 将想要获取的8位数据截取出来。
* @param i 一个int数字
* @return byte[]
*/
public static byte[] int2ByteArray(int i)
{
byte[] result = new byte[4];
result[0] = (byte)((i >> 24) & 0xFF);
result[1] = (byte)((i >> 16) & 0xFF);
result[2] = (byte)((i >> 8) & 0xFF);
result[3] = (byte)(i & 0xFF);
return result;
}
/**
* byte[]转int
* 利用int2ByteArray方法，将一个int转为byte[]，但在解析时，需要将数据还原。同样使用移位的方式，将适当的位数进行还原，
* 0xFF为16进制的数据，所以在其后每加上一位，就相当于二进制加上4位。同时，使用|=号拼接数据，将其还原成最终的int数据
* @param bytes byte类型数组
* @return int数字
*/
public static int bytes2Int(byte[] bytes)
{
int num = bytes[3] & 0xFF;
num |= ((bytes[2] << 8) & 0xFF00);
num |= ((bytes[1] << 16) & 0xFF0000);
num |= ((bytes[0] << 24) & 0xFF0000);
return num;
}
public static string Int2String(int str)
{
string S = Convert.ToString(str);
return S;
}
public static int String2Int(string str)
{
int a;
int.TryParse(str, out a);
int a1 = Convert.ToInt32(str);
return a1;
}
/*将int转为低字节在后，高字节在前的byte数组
b[0] = 11111111(0xff) & 01100001
b[1] = 11111111(0xff) & 00000000
b[2] = 11111111(0xff) & 00000000
b[3] = 11111111(0xff) & 00000000
*/
public byte[] IntToByteArray2(int value)
{
byte[] src = new byte[4];
src[0] = (byte)((value >> 24) & 0xFF);
src[1] = (byte)((value >> 16) & 0xFF);
src[2] = (byte)((value >> 8) & 0xFF);
src[3] = (byte)(value & 0xFF);
return src;
}
//将高字节在前转为int，低字节在后的byte数组(与IntToByteArray2想对应)
public int ByteArrayToInt2(byte[] bArr)
{
if (bArr.Length != 4)
{
return -1;
}
return (int)((((bArr[0] & 0xff) << 24)
| ((bArr[1] & 0xff) << 16)
| ((bArr[2] & 0xff) << 8)
| ((bArr[3] & 0xff) << 0)));
}
public static string StringToHexArray(string input)
{
char[] values = input.ToCharArray();
StringBuilder sb = new StringBuilder(input.Length * 3);
foreach (char letter in values)
{
// Get the integral value of the character.
int value = Convert.ToInt32(letter);
// Convert the decimal value to a hexadecimal value in string form.
string hexOutput = String.Format("{0:X}", value);
sb.Append(Convert.ToString(value, 16).PadLeft(2, '0').PadRight(3, ' '));
}
return sb.ToString().ToUpper();
}
}
附上查找资料过程中有用的一些资料地址：
https://www.cnblogs.com/ThreeS/articles/9377547.html
https://www.cnblogs.com/screes/p/5633383.html
还有一个关于补零的：https://blog.csdn.net/qq_22889875/article/details/79320678
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