C#生成随机字符串（数字，字母，特殊符号）

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;

 namespace ConsoleApplication1
 {
     class Program
     {
         static void Main(string[] args)
         {
             //int number;
             //int count = 7;
             //string checkCode = String.Empty;     //存放随机码的字符串   

             //System.Random random = new Random();

             //for (int i = 0; i < count; i++) //产生7位校验码
             //{
             //    number = random.Next();
             //    number = number % 36;
             //    if (number < 10)
             //    {
             //        number += 48;    //数字0-9编码在48-57
             //    }
             //    else
             //    {
             //        number += 55;    //字母A-Z编码在65-90
             //    }

             //    checkCode += ((char)number).ToString();
             //}
             //Console.WriteLine(checkCode);
             Program p = new Program();
             bool booNumber = true;
             bool booSign = true;
             bool booSmallword = true;
             bool booBigword = true;
             //p.getRandomizer(7, booNumber, booSign, booSmallword, booBigword);
             Console.WriteLine(p.getRandomizer(, booNumber, booSign, booSmallword, booBigword));
             Console.ReadLine();
         }
         public string getRandomizer(int intLength, bool booNumber, bool booSign, bool booSmallword, bool booBigword)
         {
             //定义
             Random ranA = new Random();
             int intResultRound = ;
             int intA = ;
             string strB = "";
             while (intResultRound < intLength)
             {
                 //生成随机数A，表示生成类型
                 //1=数字，2=符号，3=小写字母，4=大写字母
                 intA = ranA.Next(, );
                 //如果随机数A=1，则运行生成数字
                 //生成随机数A，范围在0-10
                 //把随机数A，转成字符
                 //生成完，位数+1，字符串累加，结束本次循环
                 if (intA ==  && booNumber)
                 {
                     intA = ranA.Next(, );
                     strB = intA.ToString() + strB;
                     intResultRound = intResultRound + ;
                     continue;
                 }
                 //如果随机数A=2，则运行生成符号
                 //生成随机数A，表示生成值域
                 //1：33-47值域，2：58-64值域，3：91-96值域，4：123-126值域
                 if (intA ==  && booSign == true)
                 {
                     intA = ranA.Next(, );
                     //如果A=1
                     //生成随机数A，33-47的Ascii码
                     //把随机数A，转成字符
                     //生成完，位数+1，字符串累加，结束本次循环
                     if (intA == )
                     {
                         intA = ranA.Next(, );
                         strB = ((char)intA).ToString() + strB;
                         intResultRound = intResultRound + ;
                         continue;
                     }

                     //如果A=2
                     //生成随机数A，58-64的Ascii码
                     //把随机数A，转成字符
                     //生成完，位数+1，字符串累加，结束本次循环
                     if (intA == )
                     {
                         intA = ranA.Next(, );
                         strB = ((char)intA).ToString() + strB;
                         intResultRound = intResultRound + ;
                         continue;
                     }

                     //如果A=3
                     //生成随机数A，91-96的Ascii码
                     //把随机数A，转成字符
                     //生成完，位数+1，字符串累加，结束本次循环
                     if (intA == )
                     {
                         intA = ranA.Next(, );
                         strB = ((char)intA).ToString() + strB;
                         intResultRound = intResultRound + ;
                         continue;
                     }

                     //如果A=4
                     //生成随机数A，123-126的Ascii码
                     //把随机数A，转成字符
                     //生成完，位数+1，字符串累加，结束本次循环
                     if (intA == )
                     {
                         intA = ranA.Next(, );
                         strB = ((char)intA).ToString() + strB;
                         intResultRound = intResultRound + ;
                         continue;
                     }
                 }

                 //如果随机数A=3，则运行生成小写字母
                 //生成随机数A，范围在97-122
                 //把随机数A，转成字符
                 //生成完，位数+1，字符串累加，结束本次循环
                 if (intA ==  && booSmallword == true)
                 {
                     intA = ranA.Next(, );
                     strB = ((char)intA).ToString() + strB;
                     intResultRound = intResultRound + ;
                     continue;
                 }

                 //如果随机数A=4，则运行生成大写字母
                 //生成随机数A，范围在65-90
                 //把随机数A，转成字符
                 //生成完，位数+1，字符串累加，结束本次循环
                 if (intA ==  && booBigword == true)
                 {
                     intA = ranA.Next(, );
                     strB = ((char)intA).ToString() + strB;
                     intResultRound = intResultRound + ;
                     continue;
                 }
             }
             return strB;
         }
     }
 }