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Problems with Row_Deleting in GridView

Posted on 2009-07-14
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Last Modified: 2012-05-07
Hi,

I'm having trouble deleting a row in GridView.  The error message states:  Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

The problem I think I'm having is finding the right code to return my datakeys.

My code is below.

Any help someone could provide would be great.

Thanks.

<asp:GridView ID="publications" runat="server"  

            AutoGenerateColumns="False"

           Width="642px" onRowDeleting="publications_RowDeleting" DataKeyNames="subjectID, publicationID">

            <Columns>

            <asp:BoundField DataField="publicationID" HeaderText="Publication ID"  ReadOnly="true" />

                <asp:TemplateField HeaderText="Subject Name">

                    <EditItemTemplate>

                        <asp:TextBox ID="subjectName" runat="server" Text='<%# Bind("subjectName") %>'></asp:TextBox>

                    </EditItemTemplate>

                    <ItemTemplate>

                        <asp:Label ID="subjectName" runat="server" Text='<%# Bind("subjectName") %>'></asp:Label>

                    </ItemTemplate>

                </asp:TemplateField>

                <asp:BoundField DataField="subjectID" ReadOnly="true"/>

                <asp:CommandField ShowDeleteButton="True" />

            

            </Columns>

        </asp:GridView>
 
 
 

protected void publications_RowDeleting(Object sender, GridViewDeleteEventArgs e)

        {

            string publicationID = publications.DataKeys[publications.SelectedIndex].Values["publicationID"].ToString();

            string subjectID = publications.DataKeys[publications.SelectedIndex].Values["subjectID"].ToString();
 

        SqlConnection conn;

        SqlCommand comm;
 

        string connectionString = ConfigurationManager.ConnectionStrings["publications"].ConnectionString;
 

        conn = new SqlConnection(connectionString);
 

        comm = new SqlCommand("Delete subjects2pub where publicationID = @publicationID and subjectID = @subjectID ", conn);

        comm.Parameters.AddWithValue("@publicationID", publicationID);

        comm.Parameters.AddWithValue("@subjectID", subjectID);

        try

        {

            conn.Open();

            comm.ExecuteNonQuery();

            BindGrid();

        }
 

        catch

        {

            MessageBox.Text = "There was an error deleting this record.";

        }

         finally

        {

            conn.Close();

        }
 

    }
 

//partial code from BindGrid() to show that I believe I've set up the DataKeyNames correctly:

BindGrid()

publications.DataKeyNames = new string[] { "publicationID" };

publications.DataKeyNames = new string[] { "subjectID" };

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Comment
Question by:Finlay11
  • 2
  • 2
5 Comments
 
LVL 41

Expert Comment

by:guru_sami
ID: 24851420
You are deleting the row and a=might be the Row is not selected i.e. SelectedIndex=-1
Use e.RowIndex like below:

string publicationID = publications.DataKeys[e.RowIndex].Values["publicationID"].ToString();
string subjectID = publications.DataKeys[e.RowIndex].Values["subjectID"].ToString();
 
0
 
LVL 8

Expert Comment

by:ppittle
ID: 24851470
What's the DataSource for hte GridView?  If you configure your GridView to use a SqlDataSource or ObjectDataSource you get deleting more or less for free and it you generally don't have to worry about these head aches.  

If you're unfimiliar with SqlDataSources, here's a good tutorial:  http://www.asp.net/learn/data-access/tutorial-47-cs.aspx
0
 

Author Comment

by:Finlay11
ID: 24851471
Now I get the error:  Object reference not set to an instance of an object.
0
 
LVL 41

Accepted Solution

by:
guru_sami earned 500 total points
ID: 24851594
looks due to this:
publications.DataKeyNames = new string[] { "publicationID" };
publications.DataKeyNames = new string[] { "subjectID" };

Try this:
publications.DataKeyNames = new string[] { "publicationID" ,"subjectID" };
0
 

Author Closing Comment

by:Finlay11
ID: 31603323
That was it!  Thanks so much
0

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