这是另一个基于guid的想法。我在Visual Studio性能测试中使用它来生成只包含字母数字字符的随机字符串。

public string GenerateRandomString(int stringLength)
{
    Random rnd = new Random();
    Guid guid;
    String randomString = string.Empty;

    int numberOfGuidsRequired = (int)Math.Ceiling((double)stringLength / 32d);
    for (int i = 0; i < numberOfGuidsRequired; i++)
    {
        guid = Guid.NewGuid();
        randomString += guid.ToString().Replace("-", "");
    }

    return randomString.Substring(0, stringLength);
}

一个使用Path.GetRandomFileName()的非常简单的实现:

using System.IO;   
public static string RandomStr()
{
    string rStr = Path.GetRandomFileName();
    rStr = rStr.Replace(".", ""); // For Removing the .
    return rStr;
}

现在只需调用RandomStr()。

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);
}

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。

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());
    }
}

这个解决方案是Random类的扩展。

使用

class Program
{
    private static Random random = new Random(); 

    static void Main(string[] args)
    {
        random.NextString(10); // "cH*%I\fUWH0"
        random.NextString(10); // "Cw&N%27+EM"
        random.NextString(10); // "0LZ}nEJ}_-"
        random.NextString();   // "kFmeget80LZ}nEJ}_-"
    }
}

实现

public static class RandomEx
{
    /// <summary>
    /// Generates random string of printable ASCII symbols of a given length
    /// </summary>
    /// <param name="r">instance of the Random class</param>
    /// <param name="length">length of a random string</param>
    /// <returns>Random string of a given length</returns>
    public static string NextString(this Random r, int length)
    {
        var data = new byte[length];
        for (int i = 0; i < data.Length; i++)
        {
            // All ASCII symbols: printable and non-printable
            // data[i] = (byte)r.Next(0, 128);
            // Only printable ASCII
            data[i] = (byte)r.Next(32, 127);
        }
        var encoding = new ASCIIEncoding();
        return encoding.GetString(data);
    }

    /// <summary>
    /// Generates random string of printable ASCII symbols
    /// with random length of 10 to 20 chars
    /// </summary>
    /// <param name="r">instance of the Random class</param>
    /// <returns>Random string of a random length between 10 and 20 chars</returns>
    public static string NextString(this Random r)
    {
        int length  = r.Next(10, 21);
        return NextString(r, length);
    }
}