NullReference Export Exception

[Pooya]

I have a RadGrid which is created programmatically. When I click the Export to Excel or Word button, it raises this issue and I can't debug what's causing it as it's inside the Telerik assembly:

What does AdjustStructureColumnCells() do? any clue what I can do?

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.] Telerik.Web.UI.Grid.Export.TableViewExporter.AdjustStructureColumnCells(GridTableView tableView) +874 Telerik.Web.UI.Grid.Export.TableViewExporter.PrepareForExportInternal(GridTableView tableView, Boolean ignorePaging, Boolean dataOnly) +267 Telerik.Web.UI.Grid.Export.TableViewExporter.page_PreRender(Object sender, EventArgs e) +23 System.EventHandler.Invoke(Object sender, EventArgs e) +0 System.Web.UI.Control.OnPreRender(EventArgs e) +8926370 System.Web.UI.Control.PreRenderRecursiveInternal() +103 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2496

[Princy]

Hello Pooya,

I tried the same scenario and its working as expected in my end. Here is the sample code that I tried.

C#:

protected void Page_Load(object sender, EventArgs e)

{

      RadGrid RadGrid1 = new RadGrid();

       RadGrid1.ID = "RadGrid1";

       PlaceHolder1.Controls.Add(RadGrid1);

       if (!IsPostBack)

       {        

           RadGrid1.AllowPaging = true;

           RadGrid1.MasterTableView.AutoGenerateColumns = false;

           RadGrid1.MasterTableView.CommandItemSettings.ShowExportToExcelButton = true;

           RadGrid1.MasterTableView.CommandItemDisplay = GridCommandItemDisplay.Top;

           RadGrid1.ExportSettings.ExportOnlyData = true;

           RadGrid1.NeedDataSource += new GridNeedDataSourceEventHandler(RadGrid1_NeedDataSource);

           RadGrid1.PageSize = 15;

           GridBoundColumn boundColumn;

           boundColumn = new GridBoundColumn();

           RadGrid1.MasterTableView.Columns.Add(boundColumn);

           boundColumn.DataField = "EmployeeID";

           boundColumn.HeaderText = "EmployeeID";

        }

 void RadGrid1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)

   {

       RadGrid radgrid= sender as RadGrid;
       radgrid.DataSource = BindGrid();

   }

   protected DataTable BindGrid()

   {

       SqlConnection con = new SqlConnection(WebConfigurationManager.ConnectionStrings["NorthwindConnectionString3"].ConnectionString);

       SqlCommand cmd = new SqlCommand("select * from Employee", con);

       SqlDataAdapter ad = new SqlDataAdapter(cmd);

       DataTable ds = new DataTable();

       ad.Fill(ds);

       return ds;

   }

}

Thanks,
Princy.

[Pooya]

I found the problem:

I had set the HierarchyDefaultExpanded property to true where there was no detailTable for a GridTableView.

I believe the Telerik assembly should be improved to either ignore this property when there is no detail table or catch and throw a proper exception message to help fixing it.