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

由于Random是不安全的，RNGCryptoServiceProvider是过时的，我最终这样做:

  // possible characters that password can have
  private const string passChars =
       "ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
       "abcdefghijklmnopqrstuvwxyz" +
       "0123456789" +
       "!@#$%.-_"
       ;

    public static string GetRandomPassword(int length)
    {
        char[] p = new char[length];
        for (int i = 0; i < length; i++)
            p[i] = passChars[RandomNumberGenerator.GetInt32(0, passChars.Length)];
        return new string(p);
    }

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)。

我一直对KeePass内置的密码生成器非常满意。因为KeePass是一个。net程序，而且是开源的，所以我决定深入研究一下它的代码。最后，我只是在我的项目中引用了标准应用程序安装中提供的KeePass.exe副本，并编写了下面的代码。多亏了KeePass，你可以看到它是多么灵活。你可以指定长度，包含/不包含哪些字符，等等。

using KeePassLib.Cryptography.PasswordGenerator;
using KeePassLib.Security;


public static string GeneratePassword(int passwordLength, bool lowerCase, bool upperCase, bool digits,
        bool punctuation, bool brackets, bool specialAscii, bool excludeLookAlike)
    {
        var ps = new ProtectedString();
        var profile = new PwProfile();
        profile.CharSet = new PwCharSet();
        profile.CharSet.Clear();

        if (lowerCase)
            profile.CharSet.AddCharSet('l');
        if(upperCase)
            profile.CharSet.AddCharSet('u');
        if(digits)
            profile.CharSet.AddCharSet('d');
        if (punctuation)
            profile.CharSet.AddCharSet('p');
        if (brackets)
            profile.CharSet.AddCharSet('b');
        if (specialAscii)
            profile.CharSet.AddCharSet('s');

        profile.ExcludeLookAlike = excludeLookAlike;
        profile.Length = (uint)passwordLength;
        profile.NoRepeatingCharacters = true;

        KeePassLib.Cryptography.PasswordGenerator.PwGenerator.Generate(out ps, profile, null, _pool);

        return ps.ReadString();
    }

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。

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