asp.net (C#): get value of a non-displayed field from a gridview selection

Question

I have a GridView control bound to an ObjectDataSource which returns a list of objects that look like this:

public class X {
    public string DisplayName {
        get;
    }
    public string Guid {
        get;
    }
}

I don't want to show the Guid property in the GridView, but I need to retrieve it when an object is selected.
I could not find a "DataValueField" property, like for the ListBox control.
As a workaround, I tried to set Visible=false for the column bound to the Guid property and get the cell text from the Row object in the SelectedIndexChanged method:

protected void GridView1_SelectedIndexChanged(object sender,EventArgs e){
    GridViewRow row = GridView1.SelectedRow;
    string id = row.Cells[2].Text; // empty
}

But this does not work - apparently if the column is not visible its Text property is left empty.

How can I get the Guid of the selected object while showing only the DisplayName?

Answer 1

Can't you use row.DataItem to get the object itself?

Answer 2

Not sure about how this works with ObjectDataSource, but with SqlDataSource we set keys on the rows of the GridView.

GridView1.DataKeyNames = new String[] {"Guid"};

Then, you can get the key by doing this:

string guid = GridView1.DataKeys[GridView1.SelectedRow.RowIndex];

Answer 3

Add "Guid" into the DataKeyNames property of the GridView. That will allow it to be available even though the column is hidden.