ASP .NET - Setting the value of a DetailsView TextBox

Question

I am attempting to use the code-behind (Page_Load or PreRender) to set a date-time textbox in a DetailsView so that it defaults to a current date-time.

What I have attempted is (one of many variations):

protected void DetailsView2_PreRender(object sender, EventArgs e)
{
        ((TextBox)DetailsView2.FindControl("date_time")).Text = 
                  DateTime.Now.ToString("d");     
}

But all that I get is a 'NullReferenceException' error.

What I am doing wrong?

Answer 1

You can use detailsview controls DataBound event to set a value within your detailsview like that :

<asp:Label ID="DetailsView2" runat="server" OnDataBound="DetailsView2_DataBound">
</asp:Label>

Code Behind :

protected void DetailsView2_DataBound(object sender, EventArgs e)
{
    DetailsView myDetailsView = (DetailsView)sender;
    if(myDetailsView.CurrentMode == DetailsViewMode.Edit)
    {
     ((TextBox)myDetailsView.FindControl("date_time")).Text = DateTime.Now.ToString("d");     
    }
}

Answer 2

To add to what Canavar suggested:

For use on a DetailsView assign like this:

<asp:DetailsView ID="DetailsView2" runat="server" AutoGenerateRows="False" 
    CellPadding="4" DataKeyNames="details_id" DataSourceID="SqlDataSource4" 
    DefaultMode="Insert" ForeColor="#333333" GridLines="None" Height="50px" 
    Width="125px" 
     AllowPaging="True"  OnPreRender="DetailsView2_DataBound">

And then in the code behind:

protected void DetailsView2_DataBound(object sender, EventArgs e)
{
    DetailsView myDetailsView = (DetailsView)sender;
    //Edit
    if (myDetailsView.CurrentMode == DetailsViewMode.Edit)
    {
        ((TextBox)myDetailsView.FindControl("TextBox2")).Text = DateTime.Now.ToString("g");
    }
    //Insert
    else if (myDetailsView.CurrentMode == DetailsViewMode.Insert)
    {
        ((TextBox)myDetailsView.FindControl("TextBox2")).Text = DateTime.Now.ToString("M/d/yyyy HH:mm");
    }
}