这里还有一个选择:

public System.String GetRandomString(System.Int32 length)
{
    System.Byte[] seedBuffer = new System.Byte[4];
    using (var rngCryptoServiceProvider = new System.Security.Cryptography.RNGCryptoServiceProvider())
    {
        rngCryptoServiceProvider.GetBytes(seedBuffer);
        System.String chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        System.Random random = new System.Random(System.BitConverter.ToInt32(seedBuffer, 0));
        return new System.String(Enumerable.Repeat(chars, length).Select(s => s[random.Next(s.Length)]).ToArray());
    }
}

在方法中实例化Random对象。

Random对象的种子来自系统时钟，这意味着如果您快速连续多次调用方法，它每次都将使用相同的种子，这意味着它将生成相同的随机数序列，这意味着您将得到相同的字符串。

为了解决这个问题，把你的Random实例移到方法本身之外(当你在做的时候，你可以摆脱对Convert和Floor和NextDouble的疯狂调用序列):

private readonly Random _rng = new Random();
private const string _chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

private string RandomString(int size)
{
    char[] buffer = new char[size];

    for (int i = 0; i < size; i++)
    {
        buffer[i] = _chars[_rng.Next(_chars.Length)];
    }
    return new string(buffer);
}

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);
    }
}

只是为了方便人们在一行代码中使用一个随机字符串

int yourRandomStringLength = 12; //maximum: 32
Guid.NewGuid().ToString("N").Substring(0, yourRandomStringLength);

PS:请记住，yourRandomStringLength不能超过32，因为Guid的最大长度为32。

你好，你可以使用WordGenerator或LoremIpsumGenerator从MMLib。RapidPrototyping nuget package。

using MMLib.RapidPrototyping.Generators;
public void WordGeneratorExample()
{
   WordGenerator generator = new WordGenerator();
   var randomWord = generator.Next();

   Console.WriteLine(randomWord);
} 

Nuget网站 Codeplex项目网站

在我的情况下，密码必须包含:

至少有一个小写字母。 至少一个大写字母。 至少有一个小数。 至少一个特殊字符。

这是我的代码:

    private string CreatePassword(int len)
    {
        string[] valid = { "abcdefghijklmnopqrstuvwxyz", "ABCDEFGHIJKLMNOPQRSTUVWXYZ", "1234567890", "!@#$%^&*()_+" };
        RNGCryptoServiceProvider rndGen = new RNGCryptoServiceProvider();

        byte[] random = new byte[len];
        int[] selected = new int[len];

        do
        {
            rndGen.GetNonZeroBytes(random);

            for (int i = 0; i < random.Length; i++)
            {
                selected[i] = random[i] % 4;
            }
        } 
        while(selected.Distinct().Count() != 4);

        rndGen.GetNonZeroBytes(random);

        string res = "";

        for(int i = 0; i<len; i++)
        {
            res += valid[selected[i]][random[i] % valid[selected[i]].Length];
        }
        return res;
    }