十年河東，十年河西，莫欺少年窮
學無止境，精益求精
一個字節數組，如下：
List<byte> by2 = new List<byte>() {0x55,0x22 };//8789
其對應的十進制的值為：8789
從上圖可知，C#中byte數組默認為低字節在前
再例如：
List<byte> by3 = new List<byte>() { 0x55, 0x22 ,0x11};//1122901
對應的十進制是：1122901
對應的16進制為：0x112255，如下：
經過上述兩個案例，C#byte數組中是按照低字節在前的方式排列的。
C#中有什么方法轉化字節流為Int嗎？
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);
涉及到兩個方法：BitConverter.ToInt16 和 BitConverter.ToInt32
但是：：BitConverter.ToInt這個方法只能轉化長度為2或者長度為4的字節數組，如果字節長度為3，則無法轉化。
譬如：
List<byte> by3 = new List<byte>() { 0x55, 0x22 ,0x11};//1122901
因此，有必要做一個通用方法
在實際業務需求中，軟硬件雙方制定的通訊協議中經常為字節流指定是高字節在前？還是低字節在前？
因此，我總結的方法如下：
#region C# 字節轉Int public static int GetValue(byte by) { return Convert.ToInt32(by); } #region 16進制轉十進制 高字節在前 /// <summary> /// 16進制轉十進制 高字節在前 /// </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> /// 高字節在前 /// </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進制轉十進制 具體參考十六進制的數值 /// </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進制轉十進制 /// </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進制轉十進制 低字節在前 /// <summary> /// 16進制轉十進制 高字節在前 /// </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> /// 低字節在前 /// </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進制轉十進制 低字節在前 /// </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進制轉十進制 低字節在前 /// </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
擴展：int數值轉字節：
var by4 = BitConverter.GetBytes(8888);//長度四字節 var by2 = BitConverter.GetBytes(Convert.ToUInt16(8888));//長度兩字節
C# base64 轉 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數組，8位表示一個普通字符，長度為："+Bys.Length); Console.WriteLine("Base64byte數組，6位表示一個base64字符，長度為：" + Bse64Bys.Length); Console.ReadLine(); }
繼續轉發別人的一篇【2020-12-24】
C#中的Byte，String，Int，Hex之間的轉換函數
轉化字符串：aabb00000000001a160100000008313233343536373839303131323233330100ffff9775 為字節數組
整理轉換方法：
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>
/// 將一條十六進制字符串轉換為ASCII
/// </summary>
/// <param name="hexstring">一條十六進制字符串</param>
/// <returns>返回一條ASCII碼</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進制字符串轉換為二進制數組
/// </summary>
/// <param name="hexstring">用空格切割字符串</param>
/// <returns>返回一個二進制字符串</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>
/// 將byte型轉換為字符串
/// </summary>
/// <param name="arrInput">byte型數組</param>
/// <returns>目標字符串</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"));
}
//將此實例的值轉換為System.String
return sOutput.ToString();
}
/// <summary>
/// 對接收到的數據進行解包（將接收到的byte型數組解包為Unicode字符串）
/// </summary>
/// <param name="recbytes">byte型數組</param>
/// <returns>Unicode編碼的字符串</returns>
public string disPackage(byte[] recbytes)
{
string temp = "";
foreach (byte b in recbytes)
temp += b.ToString("X2") + " ";//ToString("X2") 為C#中的字符串格式控制符
return temp;
}
/**
* int轉byte[]
* 該方法將一個int類型的數據轉換為byte[]形式，因為int為32bit，而byte為8bit所以在進行類型轉換時，知會獲取低8位，
* 丟棄高24位。通過位移的方式，將32bit的數據轉換成4個8bit的數據。注意 &0xff，在這當中，&0xff簡單理解為一把剪刀，
* 將想要獲取的8位數據截取出來。
* @param i 一個int數字
* @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[]轉int
* 利用int2ByteArray方法，將一個int轉為byte[]，但在解析時，需要將數據還原。同樣使用移位的方式，將適當的位數進行還原，
* 0xFF為16進制的數據，所以在其后每加上一位，就相當於二進制加上4位。同時，使用|=號拼接數據，將其還原成最終的int數據
* @param bytes byte類型數組
* @return int數字
*/
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;
}
/*將int轉為低字節在后，高字節在前的byte數組
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;
}
//將高字節在前轉為int，低字節在后的byte數組(與IntToByteArray2想對應)
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();
}
}
附上查找資料過程中有用的一些資料地址：
https://www.cnblogs.com/ThreeS/articles/9377547.html
https://www.cnblogs.com/screes/p/5633383.html
還有一個關於補零的：https://blog.csdn.net/qq_22889875/article/details/79320678
@天才卧龍的博客