C# 生成不重复随机字符串

批量生成3~6位不重复随机字符串，可自定义生成的数字字符组合。

using System;
using System.Collections.Generic;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    static class Program
    {
        /// 

        /// 应用程序的主入口点。
        /// 

        [STAThread]
        static void Main（）
        {
            Application.EnableVisualstyles（）;
            Application.SetCompatibleTextRenderingDefault（false）;
            Application.Run（new 系统唯一数（））;
        }
    }
}

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----

     文件       1594  2017-11-13 15:11  生成随机数\PartApplication.sln

    ..A..H.     72192  2017-11-13 15:22  生成随机数\PartApplication.suo

     文件         64  2017-08-09 10:49  生成随机数\WindowsFormsApplication1\bin\Debug\rand_131467205601569804.txt

     文件        450  2017-08-09 11:15  生成随机数\WindowsFormsApplication1\bin\Debug\rand_131467221040755003.txt

     文件        160  2017-08-09 11:16  生成随机数\WindowsFormsApplication1\bin\Debug\rand_131467222179415397.txt

     文件        160  2017-08-09 11:23  生成随机数\WindowsFormsApplication1\bin\Debug\rand_131467225986588261.txt

     文件        260  2017-08-09 11:23  生成随机数\WindowsFormsApplication1\bin\Debug\rand_131467226207620646.txt

     文件        200  2017-08-09 11:23  生成随机数\WindowsFormsApplication1\bin\Debug\rand_131467226371263074.txt

     文件         80  2017-08-09 14:13  生成随机数\WindowsFormsApplication1\bin\Debug\rand_131467328147914768.txt

     文件         80  2017-11-13 15:13  生成随机数\WindowsFormsApplication1\bin\Debug\rand_131550307871070090.txt

     文件        160  2017-11-13 15:13  生成随机数\WindowsFormsApplication1\bin\Debug\rand_131550307929263419.txt

     文件         80  2017-11-13 15:15  生成随机数\WindowsFormsApplication1\bin\Debug\rand_131550309516464201.txt

     文件      13824  2017-08-09 13:51  生成随机数\WindowsFormsApplication1\bin\Debug\WindowsFormsApplication1.exe

     文件      40448  2017-08-09 13:51  生成随机数\WindowsFormsApplication1\bin\Debug\WindowsFormsApplication1.pdb

     文件      11608  2017-11-13 15:16  生成随机数\WindowsFormsApplication1\bin\Debug\WindowsFormsApplication1.vshost.exe

     文件        490  2015-10-22 09:54  生成随机数\WindowsFormsApplication1\bin\Debug\WindowsFormsApplication1.vshost.exe.manifest

     文件      11776  2012-10-29 20:51  生成随机数\WindowsFormsApplication1\bin\Release\WindowsFormsApplication1.exe

     文件      24064  2012-10-29 20:51  生成随机数\WindowsFormsApplication1\bin\Release\WindowsFormsApplication1.pdb

     文件      11608  2012-10-29 20:51  生成随机数\WindowsFormsApplication1\bin\Release\WindowsFormsApplication1.vshost.exe

     文件        490  2012-02-29 11:57  生成随机数\WindowsFormsApplication1\bin\Release\WindowsFormsApplication1.vshost.exe.manifest

     文件       1229  2017-08-09 09:46  生成随机数\WindowsFormsApplication1\obj\x86\Debug\DesignTimeResolveAssemblyReferences.cache

     文件       5331  2017-11-13 15:11  生成随机数\WindowsFormsApplication1\obj\x86\Debug\DesignTimeResolveAssemblyReferencesInput.cache

     文件       3701  2017-11-13 15:16  生成随机数\WindowsFormsApplication1\obj\x86\Debug\WindowsFormsApplication1.csproj.FileListAbsolute.txt

     文件        985  2017-08-09 13:51  生成随机数\WindowsFormsApplication1\obj\x86\Debug\WindowsFormsApplication1.csproj.GenerateResource.Cache

     文件      13824  2017-08-09 13:51  生成随机数\WindowsFormsApplication1\obj\x86\Debug\WindowsFormsApplication1.exe

     文件      40448  2017-08-09 13:51  生成随机数\WindowsFormsApplication1\obj\x86\Debug\WindowsFormsApplication1.pdb

     文件        180  2017-08-09 09:46  生成随机数\WindowsFormsApplication1\obj\x86\Debug\WindowsFormsApplication1.Properties.Resources.resources

     文件        180  2017-08-09 13:51  生成随机数\WindowsFormsApplication1\obj\x86\Debug\WindowsFormsApplication1.系统唯一数.resources

     文件       5445  2012-10-29 20:51  生成随机数\WindowsFormsApplication1\obj\x86\Release\DesignTimeResolveAssemblyReferencesInput.cache

     文件        795  2012-10-29 20:51  生成随机数\WindowsFormsApplication1\obj\x86\Release\WindowsFormsApplication1.csproj.FileListAbsolute.txt

............此处省略30个文件信息