c# 数字自增，返回指定长度字符串

 调用

#region 根据值生成指定长度的“字符串”
{
  string val = "1";
  int maxlength = 4;
  Console.WriteLine($"值：{val} 最大长度：{maxlength} 结果：{NumberAddSelf.GetNumberAddSelf(val, maxlength)}");

  val = "11";
  maxlength = 4;
  Console.WriteLine($"值：{val} 最大长度：{maxlength} 结果：{NumberAddSelf.GetNumberAddSelf(val, maxlength)}");

  val = "111";
  maxlength = 4;
  Console.WriteLine($"值：{val} 最大长度：{maxlength} 结果：{NumberAddSelf.GetNumberAddSelf(val, maxlength)}");

  val = "1111";
  maxlength = 4;
  Console.WriteLine($"值：{val} 最大长度：{maxlength} 结果：{NumberAddSelf.GetNumberAddSelf(val, maxlength)}");

  val = "1111";
  maxlength = 6;
  Console.WriteLine($"值：{val} 最大长度：{maxlength} 结果：{NumberAddSelf.GetNumberAddSelf(val, maxlength)}");
} 
#endregion

结果

值：1 最大长度：4 结果：0002
值：11 最大长度：4 结果：0012
值：111 最大长度：4 结果：0112
值：1111 最大长度：4 结果：1112
值：1111 最大长度：6 结果：001112

核心方法

/// <summary>
    /// 数字自增
    /// </summary>
    public class NumberAddSelf
    { 
        /// <summary>
        /// 数字自增，返回指定长度字符串
        /// </summary>
        /// <param name="valueString">值</param>
        /// <param name="MaxLength">自增后，字符最大长度</param>
        /// <returns></returns>
        public static string GetNumberAddSelf(string NumberString, int MaxLength)
        {
            StringBuilder resultStringBuilder = new StringBuilder();
            try
            {
                int NumberInt = Convert.ToInt32(NumberString.Trim());
                NumberInt = NumberInt + 1;

                int NumberIntLength = NumberInt.ToString().Length;

                if (NumberIntLength == MaxLength)
                {
                    resultStringBuilder.Append(NumberInt);
                    return resultStringBuilder.ToString();
                }

                if (NumberIntLength >= 1 && NumberIntLength < MaxLength)
                {
                    //计算前面加多少个0
                    int res = (MaxLength - NumberIntLength);

                    for (int i = 0; i < res; i++)
                    {
                        resultStringBuilder.Append(0);
                    }

                    resultStringBuilder.Append(NumberInt);
                }

            }
            catch (Exception e)
            {
                throw new Exception("转换int类型失败");
            }

            return resultStringBuilder.ToString().Trim();
        }
    }