按顺序生成订单号

Question

我要求我需要生成一个订单号（顺序），而不是随机的，在下订单之前应该向用户显示。

        private string GenerateOrderNumber()
    {
        string OrderNumber;

        //JI-XXXXXXXXX-XXXX
        Random rnd = new Random();
        long orderPart1 = rnd.Next(100000, 9999999);
        int orderPart2 = rnd.Next(1000, 9999);

        OrderNumber = "JI-" + orderPart1 + "-" + orderPart2;

        return OrderNumber;
    }

Answer 1

怎么样：

long orderPart1 = 100000;
int orderPart2 = 1000;

Debug.WriteLine(string.Format("JI-{0}-{1}", orderPart1, orderPart2));

orderPart2++;

Debug.WriteLine(string.Format("JI-{0}-{1}", orderPart1, orderPart2));

orderPart2 = 9999;

if(orderPart2 == 9999)
{
    orderPart1++;
    orderPart2 = 1000;
}

Debug.WriteLine(string.Format("JI-{0}-{1}", orderPart1, orderPart2));

哪个输出：

JI-100000-1000
JI-100000-1001
JI-100001-1000

所以你可以创建一个类：

void Main()
{
   OrderNumberGenerator orderNumberGenerator = new OrderNumberGenerator();

   Debug.WriteLine(orderNumberGenerator.Next());
   Debug.WriteLine(orderNumberGenerator.Next());
}

// Define other methods and classes here
public class OrderNumberGenerator
{
    long orderPart1 = 100000;
    int orderPart2 = 1000;

    public string Next()
    {
        if(orderPart2 == 9999)
        {
            orderPart1++;
            orderPart2 = 1000;
        }
        else
        {
            orderPart2++;
        }

        return string.Format("JI-{0}-{1}", orderPart1, orderPart2);
    }
}

哪个输出：

JI-100000-1000
JI-100000-1001

Answer 2

以下是按顺序生成所有ID的方法：

for (long n = 0; n <= 9999999999; n++)
{
    string digits = n.ToString("0000000000");
    string output = $"JI-{digits.Substring(0, 6)}-{digits.Substring(6, 4)}";
    Console.WriteLine(output);
}