How to find the Smallest and Largest dates in a column in DataGridView

[arelius]

Hello everybody,

I have a datagridview and one of the columns contains dates.

I want to loop through the data in the column using this for loop.

string StartDate="";
                string EndDate="";
                string date="";
                foreach (DataGridViewRow dgvr in dataGridViewTasksReport.Rows)
                {
                           date = dgvr.Cells["work_date_col"].Value.ToString();
                }

But what I want to do is get the smallest date and also get the largest date.

Any idea how to do this?

Thanks guys

[DdoubleD]

If your date strings are formatted correctly for string comparisons, you can just initialize them and do a comparison for min and max for each row in your loop (pseudocode):

if minDate = "" or minDate > date then
    minDate = date;
if maxDate = "" or maxDate < date then
    maxDate = date;

[arelius]

Can you give that to me in c#

[DdoubleD]

Can you give that to me in c#

Give it a shot yourself in your loop. Then I will help you with questions. Be sure to post your new code.

[arelius]

I did make the code, but it didnt work well. here is what I have.

private DateTime StartDate;
        private DateTime EndDate;
//random date for iniitialaziton
                DateTime date = new DateTime(2000, 10, 10);
                foreach (DataGridViewRow dgvr in dataGridViewTasksReport.Rows)
                {
                    //date = dgvr.Cells["work_date_col"].Value.ToString();
                    StartDate = Convert.ToDateTime(dgvr.Cells["work_date_col"].Value);
                    EndDate = Convert.ToDateTime(dgvr.Cells["work_date_col"].Value);
                    if (StartDate > date)
                    {
                        StartDate = date;
                    }
                    if (EndDate < date)
                    {
                        EndDate = date;
                    }
                }
                MessageBox.Show(StartDate +" "+ EndDate,"getStartEndDate Error", MessageBoxButtons.OK, MessageBoxIcon.Information);

[DdoubleD]

OK. Instead of initializing "date" outside the loop, restore it inside the loop, but use the Convert.ToDateTime. This is the value from each record we want to compare to to see if it is a min or max value.

Instead of initializing Start and EndDate inside the loop, move those outside the loop (where you have "date" currently): set your StartDate to a very high value; and your EndDate to a very low value.

This should fix it--let me know.

[ddanbe]

Set a mindate to 1.1.3000
Set a maxdate to 1.1.1900
Start a loop
Read a date
if date < mindate ---> set mindate = date
if date > maxdate ---> set maxdate = date

At the end of the loop you will have the max and mindate from your list. Succes!

Edit : DdoubleD, believe you posted a few seconds before me...

[arelius]

Brilliant! It worked perfectly!

Thanks so much DdoubleD, I really appreciate it!

Also, to anyone else who is dealing with a similar problem, here is the code that worked for me:

DateTime StartDate = new DateTime(9999, 10, 10);
                DateTime EndDate = new DateTime(1000, 10, 10);
                foreach (DataGridViewRow dgvr in dataGridViewTasksReport.Rows)
                {
                    DateTime date = Convert.ToDateTime(dgvr.Cells["work_date_col"].Value);
                    if (StartDate > date)
                    {
                        StartDate = date;
                    }
                    if (EndDate < date)
                    {
                        EndDate = date;
                    }
                }
                MessageBox.Show(StartDate +" "+ EndDate,"getStartEndDate Error", MessageBoxButtons.OK, MessageBoxIcon.Information);