C＃，尝试用今天的日期检查过期日期

Question

I am trying to highlight expiration dates when its within 21days of today's date, it seems to be working for the most part. However, it seems to be highlighting next years date also. so for example : Today 2/22/2017 , it is highlighting expire dates of 2/28/2017. But it is also highlighting 2/29/2018, which is a FULL year from now. How do I get it to also include year check. Right now its just days. Code I am using below:

var now = DateTime.Now;
var expirationDate = DateTime.Parse(row.Cells[2].Value.ToString());
var TwentyOneDays = expirationDate.AddDays(-21);

var TenDays = expirationDate.AddDays(-10);

if (now > TwentyOneDays && now < expirationDate)
{
     row.DefaultCellStyle.BackColor = Color.LightSkyBlue;
     row.Cells[2].Style.BackColor = Color.Yellow;

     // .....
}

Answer 1

I suggest you using TimeSpan to know the difference between two dates. eg

DateTime expirationDate = DateTime.Now.AddDays(21);
DateTime now = DateTime.Now;

TimeSpan diff = expirationDate - now;

int days = diff.Days; // This would give 20

https://msdn.microsoft.com/en-us/library/system.timespan(v=vs.110).aspx

Answer 2

I hope this code help/s you. if you are already set your desired expired date. then we will get today's date.

The code below will retrieve all your desired expired date to current date today.

private void getexpireddate()
{
try
{
MySqlConnection con = new MySqlConnection(conn);
connect.Open();
string sql="SELECT expireddate FROM data1 where date(date) = date(now())";
MySqlDataAdapter da = new MySqlDataAdapter(sql, con);
DataTable ds = new DataTable();
da.Fill(ds);
datagrid.DataSource=ds;

}
catch(Exception ee)
{
Console.WriteLine(ee.Message);
}
}