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ASP.NET: Code Snippet - DataGrid with line numbers
Updated - 5/22/2002
In this article, we will look at a technique that will allow us to generate row numbers in the first column of a DataGrid. To generate the row numbers,
we will use the DataGridItem's ItemIndex property. Nikhil Kothari (ASP.NET team member extraordinaire) was kind
enough to inform me that the ItemIndex property was created for just such a scenario. As such, the sample below is very
simple. We will create an extra TemplateColumn in our DataGrid and bind to it the value of Container.ItemIndex. The ItemIndex
property is zero based so we will add one to it and voila, we have a row counter in our DataGrid.
The code sample below uses a couple other best pratices you should understand and be aware of:
*The code below uses structured error handling techniques in the form of the Try...Catch statement. Go here
to read more about the great new structured error handling we VBers now have.
*The code below also uses a connection string stored in a web.config configuration file. Go here to read more about
the web.config configuration file and how it can be used to store application wide data.
The Code:
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<script language="VB" runat="server">
Sub Page_Load(sender As Object, e As EventArgs)
'Create connection object
Dim myConnection As New SqlConnection(ConfigurationSettings.AppSettings("DSN_aspa"))
'Create command object
Dim myCommand As New SqlCommand("SELECT PersonName,PersonAge,PersonGender FROM tblPeople", myConnection)
'Create SqlDataReader
Dim myDataReader As SqlDataReader
Try
'Open Connection
myConnection.Open()
'Fill myDataReader using ExecuteReader method.
'Close connection using CommandBehavior.CloseConnection enumeration
myDataReader = myCommand.ExecuteReader(CommandBehavior.CloseConnection)
'Set datasource and bind DataGrid to datasource
myDataGrid.DataSource = myDataReader
myDataGrid.DataBind()
Catch myException As Exception
Response.Write("An error has occurred: " & myException.ToString())
Finally
If Not myDataReader Is Nothing Then
'Close SqlDataReader
myDataReader.Close()
End If
End Try
End Sub
</script>
<html>
<body>
<form runat="server">
<asp:datagrid id="myDataGrid"
runat="server"
AutoGenerateColumns="false" >
<columns>
<asp:templatecolumn headertext="Row Number">
<itemtemplate>
<span><%# Container.ItemIndex+1 %></span>
</itemtemplate>
</asp:templatecolumn>
<asp:templatecolumn headertext="Name">
<itemtemplate>
<span><%# Container.DataItem("PersonName") %></span>
</itemtemplate>
</asp:templatecolumn>
<asp:templatecolumn headertext="Age">
<itemtemplate>
<span><%# Container.DataItem("PersonAge") %></span>
</itemtemplate>
</asp:templatecolumn>
<asp:templatecolumn headertext="Gender">
<itemtemplate>
<span><%# Container.DataItem("PersonGender") %></span>
</itemtemplate>
</asp:templatecolumn>
</columns>
</asp:datagrid>
</form>
</body>
</html>
The Result:
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