c# 将日期时间日期与时间跨度参数进行比较

Question

目前我已经设法让我的程序正常工作，所以它比较两个日期时间日期，如果以前的记录早于或小于现在的时间，它会提醒最终用户患者需要检查。

我希望能够比较今天的日期和之前的日期，例如，如果距离最初的预订日期相隔一个月，它会执行相同的提醒。

private void PatientCheckUp()
{
    SqlConnection connection = new SqlConnection();
    Security security = new Security();
    DateTime timenow = DateTime.Now.Date;
    DateTime lastbooking = new DateTime();
    string previousBooking = "";

    try
    {
        connection.ConnectionString = connectionPath;
        connection.Open();

        SqlCommand cmd = new SqlCommand("SELECT Booking.Booking_Last_Booking, Booking.Booking_FkPatientId FROM Booking WHERE Booking.Booking_FkPatientId = @Patient_Id", connection);
        cmd.Parameters.AddWithValue("@Patient_Id", cbopatientid.Text);
        cmd.ExecuteNonQuery();

        SqlDataReader dr = cmd.ExecuteReader();
        if (dr.HasRows)
        {
            while (dr.Read())
            {
                previousBooking = security.Decrypt(dr["Booking_Last_Booking"].ToString(), security.GetPassword());
            }
        }

        lastbooking = Convert.ToDateTime(previousBooking);

        /*Currently checks if the previous booking date is less than or before today, if so it alerts the user */
        if (lastbooking.Date < timenow.Date)
        {
            MessageBox.Show("Patient requires a checks up");
        }
    }
    catch (SqlException sql)
    {
        MessageBox.Show(sql.Message);
    }
    finally
    {
        connection.Close();
        connection.Dispose();
    }
}

Answer 1

using System;

public class Program
{
    public static void Main()
    {
        DateTime dt = new DateTime();
        DateTime dt2 = new DateTime();

        dt = DateTime.Now;
        dt2 = dt.AddDays(20);


        TimeSpan ts = dt2.Subtract(dt);

        Console.WriteLine(dt.ToString());
        Console.WriteLine(dt2.ToString());

        if(ts.Days > 30)
        {
        Console.WriteLine("It has been at least a month since last check up");
        }
        else
        {
            Console.WriteLine("It has been "+ ts.Days+" days since last check up");
        }

    }
}

以上是我整理的一段示例代码，用于说明您如何能够做到这一点。您可以确定一个“月”应该是多少天，然后在它超过您指定的阈值时采取行动。

Here是我正在玩的 DotNetFiddle