如何使用C＃生成随机字符，我尝试下面的代码，但它不起作用 [英] How To Generate Random Charecters Using C#, I Tried The Code Below But It Doesnt Work

问题描述

private string GetUniqueKey()
  {
  int maxSize  = 8 ;
  int minSize = 5 ;
  char[] chars = new char[62];
  string a;
  a = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
  chars = a.ToCharArray();
  int size  = maxSize ;
  byte[] data = new byte[1];
  RNGCryptoServiceProvider  crypto = new RNGCryptoServiceProvider();
  crypto.GetNonZeroBytes(data) ;
  size =  maxSize ;
  data = new byte[size];
  crypto.GetNonZeroBytes(data);
  StringBuilder result = new StringBuilder(size) ;
  foreach(byte b in data )
  { result.Append(chars[__b % (chars.Length - )>); }
   return result.ToString();
  }

推荐答案

参见https://msdn.microsoft.com/en-us/library/system.random(v=vs.110).aspx [<一个href =https://msdn.microsoft.com/en-us/library/system.random(v=vs.110).aspx\"target =_ blanktitle =New Window> ^ ] 。生成随机数并将每一个用作可接受字符串的索引：

See https://msdn.microsoft.com/en-us/library/system.random(v=vs.110).aspx[^]. Generate random numbers and use each one as an index into the string of acceptable characters:

string list = "abcdef ... etc"
int index = nextRandom % list.length // i.e. remainder
nextCharacter = list.at(index)
repeat.

使用LINQ，

它将生成5位数的随机字符。

var chars =BCDEFGHIJKLMNOPQRSTUVWXYZ0123456789;

var random = new Random（）;

var result = new string（

Enumerable.Repeat（chars，5）

.Select（s => s [random.Next（s.Length） ）]）

.ToArray（））;

Use LINQ,
It will generate the 5 digit random characters.
var chars ="BCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
var random = new Random();
var result = new string(
Enumerable.Repeat(chars, 5)
.Select(s => s[random.Next(s.Length)])
.ToArray());

// use static classes and methods where possible
// Don't use System.Random it is not secure
private static readonly RNGCryptoServiceProvider rngCsp = new RNGCryptoServiceProvider();

private static void Encode(char[] data, char[] lexicon)
{
    //Don't let null values break your code
    if (data == null)
    {
        throw new ArgumentException("data");
    }
    if (lexicon == null)
    {
        throw new ArgumentException("lexicon");
    }
    var randomNumber = new byte[1];
    int size = data.Length;
    //use char[] rather than a string.
    //Strings are not very secure as copies are made in memory each time a string  is changed
    for (int i = 0; i < size; i++)
    {
        //Load random number into buffer.
        //Use methods that return 'void' where possible.
        rngCsp.GetBytes(randomNumber);
        int index = randomNumber[0];
        data[i] = lexicon[index % lexicon.Length];

    }

}

private static void Main(string[] args)
{
    string lexicon = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
    int size = 8;
   var data = new char[size];
    Encode(data,lexicon.ToCharArray());
    string password = new string(data);
}

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