windows phone 7 - WP7 Invalid cross-thread access - ScheduledTaskAgent

Question

In WP7 app I am calling some code to update a live tile from the onInvoke method on the ScheduledAgent class.

Getting an invalid cross-thread error.

The line it is failing on is

var fontForeground = new SolidColorBrush(Colors.White);

I understand that there are limitations ans API's that I cannot call from within this background task, but I am only trying to setup some stuff to generate my own image to display on the Live tile.

Is there something obvious I am doing wrong here.

• thanks

Update...

I have discovered this question

How can I render text on a WriteableBitmap on a background thread, in Windows Phone 7?

It is the same issue that I have and whilst there is some good dialogue on here it doesn't appear that there is an easy way to get around this?

Answer 1

Use the Dispatcher to execute the code on the UI thread instead on a background thread:

Deployment.Current.Dispatcher.BeginInvoke(()=>
    { 
         fontForeground  = new SolidColorBrush(Colors.White);
         ...        
   });