A variable declared at class level but initialized in page_load loses its scope in a button_click eventhandler? - asp.net

Question

im new to asp.net.. please bear with me if ma question is way too trivial!!! :)
im using an accordian control within an update panel. and i also have a button to save some data frm the accordian control! - This complete is a user control which is used in another .aspx page.
now in the page_load event of the user control i initialize my database connection which works absolutely fine while loading data to the accordian.. but when i click on save, in the save button click even handler the database connection object is always null..!! (even though it is initialized in the page_load) please help..
.ascx is as here:
<asp:UpdatePanel ID="PrefPanel" runat="server" >
<ContentTemplate>
<ajaxToolkit:Accordion ID="PrefAccordion" runat="server" HeaderCssClass="accordionHeader"
HeaderSelectedCssClass="accordionHeaderSelected" ContentCssClass="accordionContent"
BackColor="#E8EAF7" Height="530px" Width="500px" AutoSize="None" RequireOpenedPane="false"
BorderStyle="Solid" BorderWidth="1" BorderColor="Black">
<Panes>
<ajaxToolkit:AccordionPane ID="ProjCategoryPaneID" runat="server">
<Header > Project Category</Header>
<Content>
<asp:Panel ID="ProjCategoryPanel" runat="server" Width="100%">
<table align="center" width="100%">
<tr></tr>
<tr>
<td align="left">
<asp:CheckBoxList RepeatDirection="Vertical" TextAlign="Left" ID="ProjCategoryItem1" runat="server" AutoPostBack="false" CausesValidation="false" />
</td>
</tr>
</table>
</asp:Panel>
</Content>
</ajaxToolkit:AccordionPane>
<asp:Button ID="btnSavePref" CssClass="buttonsmall" runat="server" Text="Save" Width="60px" OnClick="btnSavePref_Click"/>
<asp:Button ID="btnCancelPref" CssClass="buttonsmall" runat="server" Text="Cancel" Width="60px" />
</ContentTemplate>
</asp:UpdatePanel>
the code behind is as here:
public partial class UserPreferences : System.Web.UI.UserControl
{
private EAReportingDAL m_DataAccessLayer = null;
// Projects Category
Panel projectCategoryPanel;
CheckBoxList projectCategoryList;
protected void Page_Load(object sender, EventArgs e)
{
String connectionString = WebConfigurationManager.ConnectionStrings ["BSCDB"].ConnectionString;
m_DataAccessLayer = new EAReportingDAL(connectionString);
LoadUserPreferences();
}
protected void btnSavePref_Click(object sender, EventArgs e)
{
string userName = this.Page.User.Identity.Name;
DataSet availabeData = m_DataAccessLayer.GetUserPreferences(this.Page.User.Identity.Name, Constants.ProjectsUIView);
}
}
in the button click event handler btnSavePref_Click() the the db connection object m_DataAccessLayer is always null, but whereas the same object in LoadUserPreferences() [which i haven't pasted here though] works fine! plz guide me where im wrong or if someone needs more details!!

Answer 1

I'm not very familiar with UpdatePanel mechanics but maybe you defined it in such a way that it bypass the Page_Load method.
What I suggest is moving the code create the data access layer to separate method then calling this method from both the page load and button click handler:
private void InitDataAccess()
{
//ignore if already created
if (m_DataAccessLayer != null)
return;
String connectionString = WebConfigurationManager.ConnectionStrings ["BSCDB"].ConnectionString;
m_DataAccessLayer = new EAReportingDAL(connectionString);
LoadUserPreferences();
}
protected void Page_Load(object sender, EventArgs e)
{
InitDataAccess();
}
protected void btnSavePref_Click(object sender, EventArgs e)
{
InitDataAccess();
string userName = this.Page.User.Identity.Name;
DataSet availabeData = m_DataAccessLayer.GetUserPreferences(this.Page.User.Identity.Name, Constants.ProjectsUIView);
}