gridview cell formatting - asp.net

Question

I have a gridview event OnRowDataBound event handler like this:
protected void MyGridviewEvent(object sender, GridViewRowEventArgs e)
{
if (e.Row.DataItem == "Duration")
{
}
}
This selects the appropriate column in the row. I'd like to change the format of that cell. This cell contains a TimeSpan and I'd like to format it hh:mm.
How's this done?
Thanks.

Answer 1

GridViewRow.DataItem returns the underlying datasource of this row. I doubt that it is a String like Duration. Normally it would be a DataRowView and you can access the datacolumn via index or name. To format a timespan you could use the .net framework 4 ToString version that takes a String with custom format providers. In earlier frameworks you have to do it manually.
VB.Net example(i hope you get it, the important part is the RowDataBound part)
Private Sub BindGrid()
Dim dt As New DataTable
dt.Columns.Add("ID", GetType(Int32)).AutoIncrement = True
dt.Columns.Add("Duration", GetType(TimeSpan))
dt.PrimaryKey = New DataColumn() {dt.Columns("ID")}
Dim newRow As DataRow = dt.NewRow
newRow("ID") = 1
newRow("Duration") = TimeSpan.FromDays(7)
dt.Rows.Add(newRow)
newRow = dt.NewRow
newRow("ID") = 2
newRow("Duration") = TimeSpan.FromMinutes(777)
dt.Rows.Add(newRow)
Me.GridView1.AutoGenerateColumns = True
Me.GridView1.DataSource = dt
Me.GridView1.DataBind()
End Sub
Private Sub GridRowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView1.RowDataBound
If e.Row.RowType = DataControlRowType.DataRow Then
Dim row As DataRowView = DirectCast(e.Row.DataItem, DataRowView)
Dim duration As TimeSpan = DirectCast(row("Duration"), TimeSpan)
e.Row.Cells(1).Text = String.Format("{0:00}:{1:00}", duration.TotalHours, duration.Minutes)
End If
End Sub

Answer 2

Try something like this
protected void MyGridviewEvent(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
TimeSpan ts = TimeSpan.Parse(DataBinder.Eval(e.Row.DataItem, "Duration").ToString());
e.Row.Cells[1].Text = String.Format("{0:t}", ts));
}
}
Where e.Row.Cells[1] is the index of the "Duration" column.