Problem getting the ReportViewerModel after upgrade to Q2'11

[Pawel]

After upgrading to q2 release (for Silverlight)  i can't get ReportViewerModel from ReportViewer.

I tried to use 

var reportViewerModel = reportViewer.DataContext as ReportViewerModel;

but datacontext for this control i always null,

then I tried 

var layoutRoot = (FrameworkElement)VisualTreeHelper.GetChild(this.reportViewer, 0);
var rvm = (ReportViewerModel)(layoutRoot.DataContext);

this gives me an error :

Specified argument was out of the range of valid values.
Parameter name: childIndex

I found that before i could use ReportViewerModel constructor. After upgrade i cannot.

I'm trying to use PrintDocumentCommand. Can i do that without ReportViewerModel?

[Steve]

Hi Pawel,

The only reason for this problem would be if the report viewer template has not yet been created e.g. you're invoking the extension method in the window/user control constructor. To make sure the template is available use OnApplyTemplate e.g.:

Copy Code

public partial class MainPage : UserControl
   {
       public MainPage()
       {
           InitializeComponent();
       }

       public override void OnApplyTemplate()
       {
           base.OnApplyTemplate();
           this.ReportViewer1.PrintTheReport();
       }
   }

   static class ReportViewerExtensions
   {
       public static void PrintTheReport(this ReportViewer reportViewer)
       {
           var layoutRoot = (FrameworkElement)VisualTreeHelper.GetChild(reportViewer, 0);
           var viewerModel = (ReportViewerModel)layoutRoot.DataContext;
           var printCommand = viewerModel.PrintReportCommand;
           if (printCommand.CanExecute(null))
           {
              printCommand.Execute(null);
           }
       }
   }

Kind regards,
Steve
the Telerik team

[Pawel]

Thanks for repply.

Unfortunately I can't use OnApplyTemplate event because i don't show this control to user, so the event don't even fire.

I want to print report  in the background (without showing any reportviewer)

[Steve]

Hi Pawel,

Currently you cannot print programmatically without the viewer and this would not change. You are not bound to use the OnApplyTemplate, we just gave it as example. You can invoke the PrintTheReport() extension method from a button click event.

All the best,
Steve
the Telerik team