Data Grid SelectedItemIndex

[developer155]

Hi, I have a datagrid and on update command I try to set its SelecyedItemIndex to whatever user chose and re-bind datagrid. The problem is that after the page loads, data grid does nto show up! What could be the problem? Here is some code:

public void Edit(object sender, DataGridCommandEventArgs e)
{
//highlight selected row
CategoryDataGrid.EditItemIndex = e.Item.ItemIndex;

CategoryDataGrid.DataSource = Catalog.Tables["Category"].DefaultView;
CategoryDataGrid.DataBind();
}

Here is datagrid:
<asp:datagrid id="CategoryDataGrid" OnEditCommand="Edit" OnDeleteCommand="Delete" OnCancelCommand="Cancel"
DataKeyField="CategoryID" AutoGenerateColumns="False" Runat="server" AlternatingItemStyle-BackColor="Beige"
FooterStyle-BackColor="Silver" FooterStyle-ForeColor="White" ItemStyle-BackColor="White" EditItemStyle-Font-Name="Verdanna"
EditItemStyle-Font-Size="8pt" EditItemStyle-BackColor="yellow" HeaderStyle-BackColor="DarkGreen"
HeaderStyle-Font-Bold="True" HeaderStyle-ForeColor="Beige" BorderColor="black" BorderWidth="1"
CellPadding="3" Font-Name="Verdanna" Font-Size="8pt" EnableViewState=False>
<Columns>
<asp:EditCommandColumn HeaderText="Action" EditText="Edit" CancelText="Cancel" ItemStyle-Wrap="False" HeaderStyle-Wrap="False" />
<asp:TemplateColumn HeaderText="Name">
<ItemTemplate>
<%# DataBinder.Eval(Container.DataItem,"Name").ToString().Replace("''","'")%>
</ItemTemplate>
</asp:TemplateColumn>
<asp:ButtonColumn HeaderText="Delete" Text="Delete" CommandName="Delete" />
</Columns>
</asp:datagrid>

 

[jbenson001]

Where are you filling: Catalog.Tables["Category"].DefaultView;?
You will have to refill your datasource after each postback.

 

[developer155]

I do that in PageLoad event.

private void Page_Load(object sender, System.EventArgs e)
{
//get category data from Session state
Catalog = (DataSet)Session["Catalog"];

if (Catalog==null)
{
//get from database
Catalog = ZoyaModaDP.LoadCatalog();
Session["Catalog"] = Catalog;
}

 

[jbenson001]

If (catalog==null) is true, then you never repopulate the session variable and therefore Catalog will be empty or NULL.

 

[developer155]

Thats not true, if Catalog==null, I do this:

if (Catalog==null)
{
//get from database
Catalog = ZoyaModaDP.LoadCatalog();
Session["Catalog"] = Catalog;//repopulate session
}

 

[jbenson001]

Sorry, you are correct, I read over it too quickly. The problem is you are accessing the dataset directly. I'm not sure the scope you put on that variable. You are saving a copy to session. This is what you should be using in the Edit event.

CategoryDataGrid.DataSource = Session["Catalog"];

 

[developer155]

thanks, I will try that. But can you explain why I it shoudl be doen that way instead of the way I did it? The scope of Catalog variable is class-level. Whats wrong with first assigning a dataset from session to class level variable and then doing CategoryDataGrid.DataSource = Catalog.Tables["Category"].DefaultView;