ASP.Net GridView doesn't refresh - asp.net

Question

I am relativity new to asp.net programming, so this one has me stumped. I manually created a dataset and set its value to the Datasource of the GridView control and then call the Databind method, but it isn't refreshing. I recreated a simple version of what I am doing so someone can advise me what I am doing wrong. I didn't include the Master file, as I didn't see it as pertainent.
Code for ASP page
<%# Page Language="vb" MasterPageFile="~/MasterPage.master" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="TestGridView._Default" %>
Updating price please stand by.
<p>
<asp:GridView ID="GV1" runat="server" AutoGenerateColumns="false">
<Columns>
<asp:BoundField DataField="VendorNumber" HeaderText="Vendor" />
<asp:BoundField DataField="PartNumber" HeaderText="Part or Sku" />
<asp:BoundField DataField="Message" HeaderText="Error Message" />
</Columns>
</asp:GridView>
</p>
<br />
<br />
<%
If Not Page.IsPostBack Then
Response.Write(Me.UpdatePricing())
End If
%>
Code for Code Behind
Public Class _Default
Inherits System.Web.UI.Page
Public Function UpdatePricing() As String
Dim showerrors As Boolean = False
Dim Head As New PnAHead()
Dim ds As DataSet = Head.GetErrorDataset()
If (ds.Tables("Errors").Rows.Count > 0) Then
showerrors = True
End If
If showerrors Then
GV1.DataSource = ds
GV1.DataBind()
End If
Return "Sales Line Number has been updated."
End Function
End Class
Class that creates the Dataset
Public Class PnAHead
Public Function GetErrorDataset() As DataSet
Dim dstemp = New DataSet()
Dim tbl As DataTable = dstemp.Tables.Add("Errors")
Dim col As DataColumn = tbl.Columns.Add("VendorNumber", System.Type.GetType("System.String"))
col.MaxLength = 20
col = tbl.Columns.Add("PartNumber", System.Type.GetType("System.String"))
col.MaxLength = 50
col = tbl.Columns.Add("Message", System.Type.GetType("System.String"))
col.MaxLength = 500
Dim row As DataRow
row = tbl.NewRow()
row("VendorNumber") = "Vendor 1"
row("PartNumber") = "Part Number 1"
row("Message") = "Message for Part 1"
tbl.Rows.Add(row)
row = tbl.NewRow()
row("VendorNumber") = "Vendor 2"
row("PartNumber") = "Part Number 2"
row("Message") = "Message for Part 2"
tbl.Rows.Add(row)
Return dstemp
End Function
End Class

Answer 1

You need to add your call to update pricing into the Page_Load event. You can also remove the Response.Write().
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
Me.UpdatePricing()
End If
End Sub
You can do this in the .aspx page by wrapping the Page_Load event in script tags, like this:
<script type="text/VB" runat="server">
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
Me.UpdatePricing()
End If
End Sub
</script>
Or you can just add the Page_Load event to your code behind, which i think is preferable as you already have a code behind page.

Answer 2

Why don't you debug your code and check of the dataset has data or not,u can do this by adding a break point on the row where you set the data source,you can get into the properties of the dataset..and you will find a magnifier icon..click it,,a pop up window will open showing the set of data retrieved.