我发现这更有帮助，因为它是一个扩展，它允许您选择代码的源代码。

static string
    numbers = "0123456789",
    letters = "abcdefghijklmnopqrstvwxyz",
    lettersUp = letters.ToUpper(),
    codeAll = numbers + letters + lettersUp;

static Random m_rand = new Random();

public static string GenerateCode(this int size)
{
    return size.GenerateCode(CodeGeneratorType.All);
}

public static string GenerateCode(this int size, CodeGeneratorType type)
{
    string source;

    if (type == CodeGeneratorType.All)
    {
        source = codeAll;
    }
    else
    {
        StringBuilder sourceBuilder = new StringBuilder();
        if ((type & CodeGeneratorType.Letters) == CodeGeneratorType.Numbers)
            sourceBuilder.Append(numbers);
        if ((type & CodeGeneratorType.Letters) == CodeGeneratorType.Letters)
            sourceBuilder.Append(letters);
        if ((type & CodeGeneratorType.Letters) == CodeGeneratorType.LettersUpperCase)
            sourceBuilder.Append(lettersUp);

        source = sourceBuilder.ToString();
    }

    return size.GenerateCode(source);
}

public static string GenerateCode(this int size, string source)
{
    StringBuilder code = new StringBuilder();
    int maxIndex = source.Length-1;
    for (int i = 0; i < size; i++)
    {

        code.Append(source[Convert.ToInt32(Math.Round(m_rand.NextDouble() * maxIndex))]);
    }

    return code.ToString();
}

public enum CodeGeneratorType { Numbers = 1, Letters = 2, LettersUpperCase = 4, All = 16 };

希望这能有所帮助。

public static class StringHelpers
{
    public static readonly Random rnd = new Random();

    public static readonly string EnglishAlphabet = "abcdefghijklmnopqrstuvwxyz";
    public static readonly string RussianAlphabet = "абвгдеёжзийклмнопрстуфхцчшщъыьэюя";

    public static unsafe string GenerateRandomUTF8String(int length, string alphabet)
    {
        if (length <= 0)
            return String.Empty;
        if (string.IsNullOrWhiteSpace(alphabet))
            throw new ArgumentNullException("alphabet");

        byte[] randomBytes = rnd.NextBytes(length);

        string s = new string(alphabet[0], length);

        fixed (char* p = s)
        {
            for (int i = 0; i < s.Length; i++)
            {
                *(p + i) = alphabet[randomBytes[i] % alphabet.Length];
            }
        }
        return s;
    }

    public static unsafe string GenerateRandomUTF8String(int length, params UnicodeCategory[] unicodeCategories)
    {
        if (length <= 0)
            return String.Empty;
        if (unicodeCategories == null)
            throw new ArgumentNullException("unicodeCategories");
        if (unicodeCategories.Length == 0)
            return rnd.NextString(length);

        byte[] randomBytes = rnd.NextBytes(length);

        string s = randomBytes.ConvertToString();
        fixed (char* p = s)
        {
            for (int i = 0; i < s.Length; i++)
            {
                while (!unicodeCategories.Contains(char.GetUnicodeCategory(*(p + i))))
                    *(p + i) += (char)*(p + i);
            }
        }
        return s;
    }
}

你还需要这个:

public static class RandomExtensions
{
    public static string NextString(this Random rnd, int length)
    {
        if (length <= 0)
            return String.Empty;

        return rnd.NextBytes(length).ConvertToString();
    }

    public static byte[] NextBytes(this Random rnd, int length)
    {
        if (length <= 0)
            return new byte[0];

        byte[] randomBytes = new byte[length];
        rnd.NextBytes(randomBytes);
        return randomBytes;
    }
}

这:

public static class ByteArrayExtensions
{
    public static string ConvertToString(this byte[] bytes)
    {
        if (bytes.Length <= 0)
            return string.Empty;

        char[] chars = new char[bytes.Length / sizeof(char)];
        Buffer.BlockCopy(bytes, 0, chars, 0, bytes.Length);
        return new string(chars);
    }
}

我想也许这也是可以接受的和简单的。

Guid.NewGuid().ToString() 

只要你使用Asp。Net 2.0或更高版本，也可以使用库调用- System.Web.Security.Membership。生成密码，但它将包括特殊字符。

要获得4个随机字符，其中至少有0个特殊字符-

Membership.GeneratePassword(4, 0)

对于随机字符串生成器:

#region CREATE RANDOM STRING WORD
        char[] wrandom = {'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','R','S','T','U','V','X','W','Y','Z'};
        Random random = new Random();
        string random_string = "";
        int count = 12; //YOU WILL SPECIFY HOW MANY CHARACTER WILL BE GENERATE
        for (int i = 0; i < count; i++ )
        {
            random_string = random_string + wrandom[random.Next(0, 24)].ToString(); 
        }
        MessageBox.Show(random_string);
        #endregion

另一个样本(在vs2013中测试):

    Random R = new Random();
    public static string GetRandomString(int Length)
    {
        char[] ArrRandomChar = new char[Length];
        for (int i = 0; i < Length; i++)
            ArrRandomChar[i] = (char)('a' + R.Next(0, 26));
        return new string(ArrRandomChar);
    }

    string D = GetRandomString(12);

我自己实现的。