Joe Stevens' BlogEverything .NET and C#

One bug I’ve come across a few times and again just recently is when using an ObjectDataSource with a GridView to update dates.  When doing the update the ObjectDataSource always uses the en-US culture and not the culture defined for the application.

The bug has been acknowledged by Microsoft but never fixed.

If you are in the US then you’ll have no problems, but if you are using a culture that uses the dd/MM/yyyy date format such as the UK or Australia you data will display in the correct format on your page, but you will get the following error when you try to save:

Cannot convert value of parameter ‘value’ from ‘System.String’ to ‘System.DateTime’

If your date is valid for the US format then you won’t get the error, but you day and month will be swapped over which is probably even more annoying.

This can be fixed by hooking into the RowUpdating event of the GridView.  The RowUpdating event is fired before the update takes place and it is simple to find any date values and change the format of them:

using System.Collections;
using System.Globalization;

protected void gvStudents_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
    foreach (DictionaryEntry de in e.NewValues)
    {
        DateTime currentDate = DateTime.MinValue;
        if (de.Value != null && DateTime.TryParse(de.Value.ToString(), out currentDate))
        {
            e.NewValues[de.Key] = currentDate.ToString(new CultureInfo("en-US"));
        }
    }
}