随笔- 7 文章- 0 评论- 2 阅读- 11926

C#简单的生成随机数

//拿一个8位数的随机数
string randomNumber=GetCode(8);
 
public string GetCode(int length)
   {
       char[] chars = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
 
       string code = string.Empty;
 
       Random random = new Random();
 
       for (int i = 0; i < length; i++)
       {
           code += chars[random.Next(chars.Length)];
       }
 
       //验证随机数是否存在过（我这里用的是ORM框架，直接用sql到数据库查一遍也一样，主要用于过滤重复）
       var list= new testModel()
       {
           test_code = code
       }.GetList<testModel>() ?? new List<testModel>();
 
       if (list.Count > 0)
       {
           return GetCode(length);
       }
       return code;
   }

/// <summary>
/// 创建数字随机数
/// </summary>
/// <param name="num"></param>
/// <returns></returns>
private static string CreateRandomNum(int num)
{
    string str = "0123456789";
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < num; i++)
    {
        sb.Append(str[new Random(Guid.NewGuid().GetHashCode()).Next(0, str.Length - 1)]);
    }
    return sb.ToString();
}

/// <summary>
/// 创建字母随机数
/// </summary>
/// <param name="letter"></param>
/// <returns></returns>
private static string CreateRandomLetter(int letter)
{
    string str = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < letter; i++)
    {
        sb.Append(str[new Random(Guid.NewGuid().GetHashCode()).Next(0, str.Length - 1)]);
    }
    return sb.ToString();
}