How to compare date values In dataGrid with current date?

Question

I have tried with

protected void gridCustomer_RowDataBound(object sender, GridViewRowEventArgs e)
{
   if (e.Row.RowType == DataControlRowType.DataRow)
   {
      DateTime olddate = Convert.ToDateTime(e.Row.Cells[9].Text);
      // Error : String was not recognized as a valid DateTime./ 'DateTime today = DateTime.Now;'
      if (olddate > today)
      {
          Label status = (Label) e.Row.FindControl("lblStatus");
          status.Text = "AutoHold";
      }
   }
}

Answer 1

Convert.ToDateTime method uses your CurrentCulture settings by default if you don't provide any IFormatProvider as a second parameter.

That means, your CurrentCulture doesn't have yyyy-MM-dd as a standard date and time format.

In such a case, you can specify your string format with DateTime.TryParseExact or DateTime.ParseExact methods like;

DateTime olddate;
if(DateTime.TryParseExact(e.Row.Cells[9].Text, "yyyy-MM-dd", 
                          CultureInfo.InvariantCulture,
                          DateTimeStyles.None, out olddate))
{
    // Your olddate will be 28/03/2015 00:00:00
}

but in old date getting '1/1/0001' where as in my grid cell i have '4/1/2015' by above your mentioned code.

Clearly, your 4/1/2015 doesn't match with yyyy-MM-dd format, that why your olddate will be the default value of DateTime which is DateTime.MinValue ( 1/1/0001) .

If your string can be more than one format, DateTime.TryParseExact has an overload that takes formats as a string array. With that, you can specify all possible formats your string.

For example;

string s = "4/1/2015";
DateTime dt;
var formats = new string[]{"yyyy-MM-dd", "M/d/yyyy"};
if(DateTime.TryParseExact(s, formats, CultureInfo.InvariantCulture,
                          DateTimeStyles.None, out dt))
{
    // Your dt will be 01/04/2015 00:00:00
}

Answer 2

use:

CultureInfo provider = CultureInfo.InvariantCulture;
dateString = "2015-03-28";
format = "yyyy-MM-dd";
try {
  result = DateTime.ParseExact(dateString, format, provider);
  Console.WriteLine("{0} converts to {1}.", dateString, result.ToString());
}
catch (FormatException) {
  Console.WriteLine("{0} is not in the correct format.", dateString);
}

MSDN

Answer 3

Use DateTime.ParseExact

string res = "2012-07-08";
DateTime d = DateTime.ParseExact(res, "yyyy-MM-dd", CultureInfo.InvariantCulture);
Console.WriteLine(d.ToString("MM/dd/yyyy")); // can set any format

Answer 4

Replace this line in code

DateTime olddate = DateTime.ParseExact(e.Row.Cells[9].Text, "yyyy-MM-dd", CultureInfo.InvariantCulture);

Convert.ToDateTime will throw exception if there is a difference in current culture and the format of date time string