public void EditTask(object sender, ExecuteEventArgs args)
 {
     var taskItem = args.MethodParameter as TaskItem;
     SendNavigationRequestMessage(new Uri(string.Format("/Views/DetailsView.xaml?taskId={0}", taskItem.TaskId), UriKind.Relative));
 }
 public void DeleteTask(object sender, ExecuteEventArgs args)
 {
     var taskItem = args.MethodParameter as TaskItem;
     Tasks.Remove(taskItem);
 }