Threading Issue : RadMap Inside Window Form Element Host

[Sanjay]

Hi There

I'm calling WPF RadMap usercontrol inside Window form usercontrol using elementHost. But while calling using UI Virtualization it gives error as shown below.The below code works fine in standalone WPF usercontrol.

MapShapeDataVirtualizationSource map = new MapShapeDataVirtualizationSource();
               AsyncShapeFileReader reader = new AsyncShapeFileReader();
               reader.ToolTipFormat = "FieldName";
               reader.Source = new Uri(rShape["path"].ToString() + ".shp", UriKind.RelativeOrAbsolute);
               reader.DataSource = new Uri(rShape["path"].ToString() + ".dbf", UriKind.RelativeOrAbsolute);
               map.Reader = reader;
               map.ReadAsync(); // Give the error .See the attached Error screen shot.
               map.ClearCache = false;
               vLayer.VirtualizationSource = map;
               vLayer.UseBitmapCache = false;
               vLayer.RefreshVirtualSource();
               this.radMapNaveo.Items.Add(vLayer);

The below code works.

AsyncShapeFileReader reader = new AsyncShapeFileReader();
               reader.ToolTipFormat = "FieldName";
               reader.Source = new Uri(rShape["path"].ToString() + ".shp", UriKind.RelativeOrAbsolute);
               reader.DataSource = new Uri(rShape["path"].ToString() + ".dbf", UriKind.RelativeOrAbsolute);
               vLayer.Reader = reader;
               vLayer.UseBitmapCache = false;
               vLayer.RefreshVirtualSource();
               this.radMapNaveo.Items.Add(vLayer);

 
Later I found that this is threading issue related to STA architecture, as it also throw the error "The calling thread must be STA,because many UI components require this". See the attachment.

Cheers. 

[Petar Mladenov]

Hi Sanjay,

In Winforms you can work with UI controls only from the main UI thread. ReadAsync() uses internally BackgroundThreads which is not supported when you are in ElementHost. 
What can you do is to wait for the AsycReader to read all shape, use ReadShapeDataCompleted event and add the RadMap in the ElementHost when read is completed. While reading you can have some kind of BusyIndicator / Waiting Bar.
We hope this helps you proceed further.

Regards,
Petar Mladenov
Telerik