我创建的这个类使用RNGCryptoServiceProvider，它是灵活的。例子:

var generator = new PasswordGenerator(minimumLengthPassword: 8,
                                      maximumLengthPassword: 15,
                                      minimumUpperCaseChars: 2,
                                      minimumNumericChars: 3,
                                      minimumSpecialChars: 2);
string password = generator.Generate();

 Generate random password of specified length with 
  - Special characters   
  - Number
  - Lowecase
  - Uppercase

  public static string CreatePassword(int length = 12)
    {
        const string lower = "abcdefghijklmnopqrstuvwxyz";
        const string upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        const string number = "1234567890";
        const string special = "!@#$%^&*";

        var middle = length / 2;
        StringBuilder res = new StringBuilder();
        Random rnd = new Random();
        while (0 < length--)
        {
            if (middle == length)
            {
                res.Append(number[rnd.Next(number.Length)]);
            }
            else if (middle - 1 == length)
            {
                res.Append(special[rnd.Next(special.Length)]);
            }
            else
            {
                if (length % 2 == 0)
                {
                    res.Append(lower[rnd.Next(lower.Length)]);
                }
                else
                {
                    res.Append(upper[rnd.Next(upper.Length)]);
                }
            }
        }
        return res.ToString();
    }

使用Random和linq-to-objects来要求每个组都有一个很简单的方法。

随机分组 从第一组中选择随机金额 从以下组中选择剩余的随机金额

Random rand = new Random();
int min = 8;
int max = 16;
int totalLen = rand.Next(min, max);
int remainingGroups = 4;
                
string[] allowedLowerChars = "a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z".Split(',');           
string [] allowedUpperChars = "A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z".Split(',');
string [] allowedNumbers = "1,2,3,4,5,6,7,8,9,0".Split(',');
string [] allowedSpecialChars = "!,@,#,$,%,&,?".Split(',');


var password = allowedLowerChars.OrderBy(c => rand.Next()).Take(rand.Next(1, totalLen-remainingGroups--)).ToList();
password.AddRange(allowedUpperChars.OrderBy(c => rand.Next()).Take(rand.Next(1, totalLen-password.Count-remainingGroups--)).ToList());
password.AddRange(allowedNumbers.OrderBy(c => rand.Next()).Take(rand.Next(1, totalLen-password.Count-remainingGroups--)).ToList());
password.AddRange(allowedSpecialChars.OrderBy(c => rand.Next()).Take(totalLen-password.Count).ToList());
password = password.OrderBy(c => rand.Next()).ToList(); // randomize groups

对于这种类型的密码，我倾向于使用可能生成更容易“使用”的密码的系统。短的，通常由发音片段和一些数字组成，并且没有字符间的歧义(这是0还是O?是1还是I?)类似的

string[] words = { 'bur', 'ler', 'meh', 'ree' };
string word = "";

Random rnd = new Random();
for (i = 0; i < 3; i++)
   word += words[rnd.Next(words.length)]

int numbCount = rnd.Next(4);
for (i = 0; i < numbCount; i++)
  word += (2 + rnd.Next(7)).ToString();

return word;

(直接在浏览器中输入，因此仅作为参考。同时，要多加单词)。

这是我快速拼凑的东西。

    public string GeneratePassword(int len)
    {
        string res = "";
        Random rnd = new Random();
        while (res.Length < len) res += (new Func<Random, string>((r) => {
            char c = (char)((r.Next(123) * DateTime.Now.Millisecond % 123)); 
            return (Char.IsLetterOrDigit(c)) ? c.ToString() : ""; 
        }))(rnd);
        return res;
    }

我喜欢生成密码，就像生成软件密钥一样。您应该从遵循良好实践的字符数组中进行选择。采用@Radu094回答的内容并修改它以遵循良好的实践。不要把每个字母都放在字符数组中。有些信在电话里更难读懂。

您还应该考虑对生成的密码使用校验和，以确保它是由您生成的。实现这一点的一个好方法是使用LUHN算法。