[MetadataType(typeof(EmployeeMetadata))]
public partial class Employee
{
    public override string ToString()
    {
        return string.Format("{0} {1}", this.FirstName, this.LastName);
    }
}

And this is how this shows up in the dialog …

• Apply the DisplayColumn attribute to your entities metadata class. If you don’t need to do any computations or formatting and just want to return a column value you can apply the DisplayColumnAttribute to your entities meta-class and set the DisplayColumn value to the column value you want to use for display purposes. Below is a quick example where I am using the Customer’s ContactName column as the display value (line 5) …

[Category("People")]
[Description("You can use this page to find out what your customers are up to")]
[DisplayName("Customers")]
//  Use the ContactName column for the display name
[DisplayColumn("ContactName")]
public class CustomerMetadata
{
    [DisplayName("ID")]
    public object CustomerID { get; set; }
    [DisplayName("Company")]
    public object CompanyName { get; set; }
    [DisplayName("Name")]
    public object ContactName { get; set; }
    [DisplayName("Title")]
    public object ContactTitle { get; set; }

    //  Columns I want hidden
    [ScaffoldColumn(false)]
    public object Fax { get; set; }
    [ScaffoldColumn(false)]
    public object Phone { get; set; }
    [ScaffoldColumn(false)]
    public object PostalCode { get; set; }
    [ScaffoldColumn(false)]
    public object Country { get; set; }
    [ScaffoldColumn(false)]
    public object Orders { get; set; }
}

And this is how this shows up in the dialog …

The only caveat here is that if you have applied a custom format to the DisplayColumn using the DisplayFormat attribute, it doesn’t look like this custom formatting will be applied when the display string is retrieved. Probably not a big deal especially since you can apply formatting using the ToString method I mention above, but it is still interesting. Here is a quick example of what I mean …

I have added the DisplayColumn attribute to my Customer metadata class like so …

//  Use the ContactName column for the display name
[DisplayColumn("ContactName")]
public class CustomerMetadata {}

And applied the DisplayFormat attribute to the ContactName property like so …

[DisplayFormat(DataFormatString = "{0} testing")]
public object ContactName { get; set; }

Then when I request the DisplayString for the Customer rows, the testing suffix is not applied …

I didn’t expect that. But like I said, it really isn’t a huge deal because you can always use ToString to format the column value.

Plugging in jquery’s Thickbox

And finally, if you wish to use a different dialog box instead of the browsers default you can plug that into the List.aspx page template as well. I choose to use jquery’s thickbox, but if you prefer the AjaxControlToolkit’s ModalPopup you could easily implement that as well. Here is what I did to make use of the thickbox.

• Add the markup for the grids ItemTemplate. There are 3 main controls in my template, a link that when clicked displays the thickbox, a hidden ASP button control that is used to force the postback that causes the row to be deleted and a hidden panel that displays the delete message for the row.

• Next, I added a bit of code that runs as the grids rows are bound to the data items. I first extract the thickbox hyperlink, hidden delete button, the confirm button and the panel that contains the message. After I have all of these controls I populate the NavigateUrl property on the Hyperlink to include the correct options (including the ClientID of the rows confirmation message) and use the OnClientClick property of the Yes button to issue the delete by causing the hidden delete button to initiate a postback.

protected void RowDataBound(object sender, GridViewRowEventArgs args)
{
    if (!table.IsReadOnly && args.Row.RowType == DataControlRowType.DataRow)
    {
        //  track down the controls
        HyperLink deleteLink = (HyperLink)args.Row.FindControl("btnDelete");
        Button deleteCommand = (Button)args.Row.FindControl("deleteCommand");
        Button yes = (Button)args.Row.FindControl("yes");
        Panel deleteConfirm = (Panel)args.Row.FindControl("deleteConfirm");

        //  point the thickbox at the confirmation panel for this row
        const string thickBoxOptionsFormat = "#TB_inline?height=90&width=350&inlineId={0}&modal=true";
        deleteLink.NavigateUrl = string.Format(thickBoxOptionsFormat, deleteConfirm.ClientID);

        //  when the user clicks OK, locate the hidden Delete button
        //  and click it
        const string deleteFormat = "$('#{0}').click(); return false;";
        yes.OnClientClick = string.Format(deleteFormat, deleteCommand.ClientID);
    }
}

Conclusion

Again, I am pleased with the flexibility that Dynamic Data provides me. It’s these seemingly simple requirements of providing a custom delete message that I figured would be difficult to do with Dynamic Data.

That’s it. Enjoy!

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