RadGrid disappears

[calm_boy]

Hi.

I am using a radgrid in an update panel. When I click the edit button, the radgrid disappears and when i refresh the page, it reappears in edit mode as requested initially. I have tried removing the update panel, and it doesn't make any difference.

Any help would be appreciated.

[Vlad]

Hi calm_boy,

I suspect that you are using simple data-binding with DataBind() and nothing data-binds the grid on post-back.

Kind regards,
Vlad
the Telerik team

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[Princy]

Hi calm_boy,

Go through the following demo link to get details about AdvanceDataBinding techniques.
Advanced data-binding

Thanks
Princy.

[calm_boy]

Yes. I have found out that I have to use the advanced data binding approach. But then, when I use the NeedDataSource event, it doesn't work either, so what am I supposed to do?

[calm_boy]

I have found a solution.

I attach a datasource to the radgrid which i then populate dynamically in my code behind file. That way, it thinks it has a datasource all the time.

[SchaF]

Can someone explain to me why this is happening. I have my NeedDataSource event. When the page intially loads, I make a trip to the DB to get the table, then bind it using simple binding, ie radGrid.DataSource = object; radGrid.DataBdind(); Then when I click the edit button, the edit box pops up, I make my changes and hit update, and it fires the NeedDataSource event again, and then when it gets back to the page, my changes are gone. How do I save these changes? Where do I get the values that were edited. If the NeedDatasource is rebinding on the edit/update, then how am I ever supposed to get the users changes?

[Princy]

Hi Schaf,

I guess you want to perform the Edit/Insert/Delete operation using Server side code and NeedDataSource event. Please have a look at the following example code snippet.

ASPX:

<telerik:RadGrid ID="RadGrid1" runat="server" OnNeedDataSource="RadGrid1_NeedDataSource"
    AllowPaging="true" OnUpdateCommand="RadGrid1_UpdateCommand" OnInsertCommand="RadGrid1_InsertCommand"
    OnDeleteCommand="RadGrid1_DeleteCommand" >
    <MasterTableView AutoGenerateColumns="False" DataKeyNames="OrderID" CommandItemDisplay="Top">
        <Columns>
            <telerik:GridButtonColumn CommandName="Delete" Text="Delete" UniqueName="DeleteColumn" />
            <telerik:GridBoundColumn HeaderText="OrderID" DataField="OrderID"  UniqueName="OrderID" />
            <telerik:GridBoundColumn HeaderText="EmployeeID" DataField="EmployeeID" UniqueName="EmployeeID" />
            <telerik:GridBoundColumn HeaderText="OrderDate" DataField="OrderDate" UniqueName="OrderDate" />
            <telerik:GridBoundColumn HeaderText="ShipName" DataField="ShipName" UniqueName="ShipName" />
            <telerik:GridEditCommandColumn UniqueName="EditCommandColumn" />
        </Columns>
    </MasterTableView>
</telerik:RadGrid>

C#:

public static string connection = WebConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
   SqlConnection conn = new SqlConnection(connection);
   public SqlCommand SqlCommand = new SqlCommand();
   DataTable dt1 = new DataTable();

   protected void RadGrid1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
   {
       string selectQuery1 = "SELECT [OrderID], [CustomerID], [EmployeeID], [OrderDate], [ShipName] FROM [Orders]" ;
       SqlDataAdapter adapter1 = new SqlDataAdapter(selectQuery1, conn);
       conn.Open();
       adapter1.Fill(dt1);
       conn.Close();
       RadGrid1.DataSource = dt1;
   }
   protected void RadGrid1_UpdateCommand(object sender, GridCommandEventArgs e)
   {
      if (e.Item is GridEditableItem && e.Item.IsInEditMode)
       {
           GridEditableItem edit = (GridEditableItem)e.Item;
           string OrderID = edit.GetDataKeyValue("OrderID").ToString();
           TextBox txt = (TextBox)edit["EmployeeID"].Controls[0];
           TextBox txt1 = (TextBox)edit["OrderDate"].Controls[0];
           TextBox txt2 = (TextBox)edit["ShipName"].Controls[0];
           conn.Open();
           string query = "UPDATE Orders SET EmployeeID ='" + txt.Text + "', OrderDate='" + txt1.Text + "',ShipName='" + txt2.Text + "' WHERE OrderID = '" + OrderID + "'";
           SqlCommand cmd = new SqlCommand(query, conn);
           cmd.ExecuteNonQuery();
           conn.Close();
       }
   }
   protected void RadGrid1_InsertCommand(object sender, GridCommandEventArgs e)
   {
       if (e.Item is GridEditableItem )
       {
           GridEditableItem edit = (GridEditableItem)e.Item;
           TextBox tx=(TextBox)edit["OrderID"].Controls[0];
           TextBox txt = (TextBox)edit["EmployeeID"].Controls[0];
           TextBox txt1 = (TextBox)edit["OrderDate"].Controls[0];
           TextBox txt2 = (TextBox)edit["ShipName"].Controls[0];
           conn.Open();
           string query = "INSERT into Orders (OrderID,EmployeeID,OrderDate,ShipName ) VALUES ('"+ tx.Text+ "','" + txt.Text + "','" + txt1.Text + "','" + txt2.Text + "')";
           SqlCommand cmd = new SqlCommand(query, conn);
           cmd.ExecuteNonQuery();
           conn.Close();
       }
   }
   protected void RadGrid1_DeleteCommand(object sender, GridCommandEventArgs e)
   {
       if (e.Item is GridEditableItem)
       {
           GridEditableItem edit = (GridEditableItem)e.Item;
           string OrderID = edit.GetDataKeyValue("OrderID").ToString();
           conn.Open();
           string query = "DELETE from Orders Where OrderID = '" + OrderID + "'";
           SqlCommand cmd = new SqlCommand(query, conn);
           cmd.ExecuteNonQuery();
           conn.Close();
       }
   }

Thanks,
Princy