DateTimeControl in Sharepoint (c#)

Question

Hi all!

I'm trying to change the default values in the "time" drop down list that the DateTimeControl displays in Sharepoint. I want an increment of 15, not 5 minutes. Anybody has any idea how this could be done? Can I overload a method or something?

Answer 1

Unfortunately this is not possible using the out of the box DateTime field.

A SharePoint field is made up of 2 main parts. The data structure (in code) and the various views (namely in a list, new/edit/view, admin [when adding to a list]). The data structure out of the box is a standard .NET DateTime field. Unfortunately the views only give the increment by 5 minutes.

You can create your own by inheriting from the default field. MSDN has a decent explaination of how. Nick Sevens has a much clearer explanation.

Unfortunately (as with most SharePoint customizations) creating your own field in CAML can be tricky.

This project on CodePlex might be a good starting point. It's licensed under the GPL so you can modify it.

Answer 2

As a matter of fact both the time drop down and its initializers are implemented as private data members of the DateTimeControl class so you can not change the values directly. However, the minutes drop down is prepared inside OnPreRender, we can get the control and reset its values indirectly to get desired behavior. Here is one approach

public class MyDateTimeControl : DateTimeControl
{
    protected override void Render(HtmlTextWriter output)
    {
        DropDownList minuteControl = null;
        string[] newMinutesRange = new string[] { "00", "15", "30", "45" };
        string[] newMinutesRangeExt = new string[] { "00", "15", "30", "45", "" };
        int index = 0;
        int selectedMinutes;

        try
        {
            if (!this.DateOnly && this.Controls.Count == 4)
            {
                minuteControl = (DropDownList)this.Controls[2];
            }
        }
        catch { }

        if (minuteControl != null && !this.DateOnly)
        {
            selectedMinutes = Convert.ToInt32(minuteControl.SelectedValue);
            if (selectedMinutes % 15 > 0)
            {
                index = 4;
                newMinutesRangeExt.SetValue(selectedMinutes.ToString(), index);
                newMinutesRange = newMinutesRangeExt;
            }
            else
            {
                index = selectedMinutes / 15;
            }

            minuteControl.Items.Clear();
            minuteControl.SelectedIndex = 0;
            minuteControl.DataSource = newMinutesRange;
            minuteControl.DataBind();
            minuteControl.SelectedIndex = index;
        }

        base.Render(output);            
    }
}

Hope this helps