A GridView contains a property called "DataKeyNames" which is typically the primary key of each record. This is often useful when you need to grab the unique recordID for each row. To get ID for a single selected row, you can do something like this:
If you are using RowUpdating, RowDatabound, etc.
Dim intId as Integer= GridView1.DataKeys(e.RowIndex).Value
By name :
Dim intId as Integer= GridView1.DataKeys("ID").Value
By Index:
Dim intId as Integer= GridView1.DataKeys(0).Value
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:HiddenField ID="hdID" runat="server" Value='<%# Eval("ID") %>' />
</ItemTemplate>
</asp:TemplateField>
To get the ID value for a group of records in a Gridview, you can do something like this:
Protected Sub btn_ExportSelectedRecords_Click(ByVal sender As Object, ByVal e As System.Web.UI.ImageClickEventArgs)
'First loop through the GridView and see which IDs were selected. I use the StringBuilder since the list could be a very long list
Dim sb As New StringBuilder
Dim row As GridViewRow
For Each row In searchResultsGridView.Rows
If (CType(row.FindControl("CheckBox1"), CheckBox)).Checked Then
lblSelectedIDDirs.Text = sb.Append(searchResultsGridView.DataKeys(row.RowIndex).Value.ToString() + ","c).ToString()
End If
Next
End Sub
<asp:GridView ID="searchResultsGridView" Runat="server" DataSourceID="searchResultsDataSource" AllowSorting="true" AllowPaging="true" PageSize="20"
DataKeyNames="IDDir">
<Columns>
<asp:TemplateField HeaderText="">
<ItemTemplate>
<asp:HiddenField ID="hdID" runat="server" Value='<%# Eval("IDDir") %>' />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="">
<ItemTemplate>
<asp:Checkbox id="Checkbox1" runat="server" />
</ItemTemplate>
</asp:TemplateField>