Get ID from selected row in gridview using image button

[primagic]

I have a gridview with a template field column which has an image button using 'select' command.

<asp:TemplateField ShowHeader="False" ItemStyle-HorizontalAlign="Center">
                                <ItemTemplate>
                                    <asp:ImageButton ID="btnSelect" runat="server" CausesValidation="False" ImageUrl="images/select_icon.png"
                                        CommandName="Select" Text="Select" OnClick="LinkButton1_Click"   
                                    />
                                </ItemTemplate>
                            </asp:TemplateField>

I am trying to get the value of a hidden column from the selected row and parse it as a parameter to add it to a database.

In my code behind I have for getting value:

Protected Sub LinkButton1_Click(sender As Object, e As EventArgs)
        Dim clickedRow As GridViewRow = TryCast(DirectCast(sender, ImageButton).NamingContainer, GridViewRow)
        Dim lblID As Label = DirectCast(clickedRow.FindControl("CertificateID"), Label)
        lblSelectedRecord.text = lblID.Text
    End Sub

Using as a parameter in my stored procedure:

cmd.Parameters.Add("@CertificateID", SqlDbType.Int).Value = lblSelectedRecord.Text.Trim

I am getting the error 'Object reference not set to an instance of an object.' on the line

blSelectedRecord.text = lblID.Text

Any ideas

 

[jbenson001]

First you should be using the SelectdIndexChanging event of the gridview. There is also a SelectedIndexChanged, but I think you want the former.
Second, are you trying to get the ID of the row to do a Select or Update from the database?

 

[shaunk]

This example is for a linkbutton
There is another parameter called commandArgument. In this case I am sending the value of two fieldsin the gridviewrow.
CommandArgument='<%# Container.DataItem("service_request_id") & "%" & Container.DataItem("Client_Id") %>'

You can parse the value you set this parameter to in the gridview_RowCommand event
Protected Sub GridView1_RowCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewCommandEventArgs) Handles GridView1.RowCommand

Dim wc As WebControl = CType(e.CommandSource, WebControl)

If TypeOf wc Is LinkButton Then
Dim gvrSelected As GridViewRow
Dim lnkEdit As LinkButton = DirectCast(e.CommandSource, LinkButton)
gvrSelected = DirectCast(lnkEdit.Parent.Parent, GridViewRow)

Select Case e.CommandName
Case "Select"
Dim identifierArray() As String
identifierArray = Split(Convert.ToString(e.CommandArgument), "%")

etc........


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