c＃將ascii值的字節數組轉換為整數數組

Question

我有一個50字節的字節數組 ，表示5整數作為ascii字符值。 每個整數值表示為10個字節：

byte[] receiveBytes = new byte[] {
  20, 20, 20, 20, 20, 20, 20, 20, 20, 49,  // 9 spaces then '1'
  20, 20, 20, 20, 20, 20, 20, 20, 20, 50,  // 9 spaces then '2'
  20, 20, 20, 20, 20, 20, 49, 50, 51, 52,  // 6 spaces then '1' '2' '3' '4'
  20, 20, 20, 20, 20, 20, 53, 56, 48, 49,  // 6 spaces then '5' '8' '0' '1'
  20, 20, 20, 20, 20, 20, 20, 57, 57, 57}; // 7 spaces then '9' '9' '9'

請注意， 20是space的ascii代碼， [48..57]是0..9位的ascii代碼。

如何將字節數組轉換為整數數組 （ int[] intvalues == [1, 2, 1234, 5801, 999] ）？

我先嘗試將字節數組轉換為字符串，然后將字符串轉換為整數，如下所示：

string[] asciival = new string[10];
int[] intvalues = new int[5];

Byte[] receiveBytes = '20202020202020202049  //int value = 1
                       20202020202020202050  //int value = 2
                       20202020202049505152  //int value = 1234
                       20202020202053564849  //int value =5801
                       20202020202020575757';//int value = 999

asciival[0] = Encoding.ASCII.GetString(receiveBytes, 0, 10);
asciival[1] = Encoding.ASCII.GetString(receiveBytes, 10, 10);

intvalues[0] = int.Parse(asciival[0]);
intvalues[1] = int.Parse(asciival[1]);

但是沒有更簡單的方法將字節數組復制到字符串數組中嗎？

Answer 1

for循環可以簡化寫入：

byte[] recv = new byte[]{ /* ... */ }

int[] intvalues = new int[recv.Length / 10];

for(int pos = 0; pos < recv.Length; pos += 10)
    intvalues[pos / 10] = int.Parse(Encoding.ASCII.GetString(recv, pos, pos + 10));

Answer 2

我建議使用Linq ：

• 在10項（即10 byte ）塊上拆分初始數組
• 過濾每個塊中的數字（ '0' .. '9' ）
• Aggergate數字為單個整數

執行：

  using System.Linq;
  ...

  Byte[] receiveBytes = new byte[] {
    20, 20, 20, 20, 20, 20, 20, 20, 20, 49,  // 9 spaces then '1'
    20, 20, 20, 20, 20, 20, 20, 20, 20, 50,  // 9 spaces then '2'
    20, 20, 20, 20, 20, 20, 49, 50, 51, 52,  // 6 spaces then '1' '2' '3' '4'
    20, 20, 20, 20, 20, 20, 53, 56, 48, 49,  // 6 spaces then '5' '8' '0' '1'
    20, 20, 20, 20, 20, 20, 20, 57, 57, 57}; // 7 spaces then '9' '9' '9'

  int[] intvalues = Enumerable.Range(0, receiveBytes.Length / 10)
    .Select(index => receiveBytes
       .Skip(index * 10) // Skip + Take: splitting on 10-items chunks
       .Take(10)                  
       .Where(b => b >= '0' && b <= '9') // just digits 
       .Aggregate(0, (s, a) => s * 10 + a - '0')) 
    .ToArray();

測試

  Console.Write(string.Join(", ", intvalues));

結果：

  1, 2, 1234, 5801, 999

請注意， 10位數字很可能溢出 int因為最大int值（ int.MaxValue ）僅為2147483647 。 要將初始byte[]為string您可以再次使用Linq ：

  var result = Enumerable
    .Range(0, receiveBytes.Length / 10)
    .Select(index => receiveBytes
       .Skip(index * 10) // Skip + Take: splitting on 10-items chunks
       .Take(10)
       .Select(b => b.ToString("00"))) // enforce leading "0" if necessary
    .Select(items => string.Concat(items));

  string text = string.Join(Environment.NewLine, result);

  Console.Write(text);

結果

20202020202020202049
20202020202020202050
20202020202049505152
20202020202053564849
20202020202020575757

Answer 3

你可以試試這個： -

using System;
using System.Text; 
class Example
{ 
  public static void Main()
  { 
  // Define a string. 
  String original = "ASCII Encoding"; 
 // Instantiate an ASCII encoding object.
   ASCIIEncoding ascii = new ASCIIEncoding(); 
// Create an ASCII byte array.
  Byte[] bytes = ascii.GetBytes(original); 
// Display encoded bytes.
  Console.Write("Encoded bytes (in hex): ");
  foreach (var value in bytes)
    Console.Write("{0:X2} ", value);
    Console.WriteLine(); // Decode the bytes and display the resulting Unicode string. 
    String decoded = ascii.GetString(bytes);
    Console.WriteLine("Decoded string: '{0}'", decoded);
  }
}