C# 4 and .NET 4

Course order application ❘ 1375
private void AddListItem(LabelIdMapping labelIdMapping)
{
listOrders.Items.Add(labelIdMapping);
}
The ListBox control contains elements of the LabelIdMapping class. This class is used to display the labels
of the messages in the list box, but to keep the ID of the message hidden. The ID of the message can be used
to read the message at a later time:
private class LabelIdMapping
{
public string Label { get; set; }
public string Id { get; set; }
}
public override string ToString()
{
return Label;
}
The ListBox control has the SelectedIndexChanged event associated with the method
listOrders_SelectionChanged(). This method gets the LabelIdMapping object from the current
selection, and uses the ID to peek at the message once more with the PeekById() method. Then the content
of the message is displayed in the TextBox control. Because by default the priority of the message is not
read, the property MessageReadPropertyFilter must be set to receive the Priority:
private void listOrders_SelectionChanged(object sender,
RoutedEventArgs e)
{
LabelIdMapping labelId = listOrders.SelectedItem as LabelIdMapping;
if (labelId == null)
return;
orderQueue.MessageReadPropertyFilter.Priority = true;
Message message = orderQueue.PeekById(labelId.Id);
CourseOrder order = message.Body as CourseOrder;
if (order != null)
{
textCourse.Text = order.Course.Title;
textCompany.Text = order.Customer.Company;
textContact.Text = order.Customer.Contact;
buttonProcessOrder.IsEnabled = true;
}
if (message.Priority > MessagePriority.Normal)
{
labelPriority.Visibility = Visibility.Visible;
}
else
{
labelPriority.Visibility = Visibility.Hidden;
}
}
else
{
MessageBox.Show("The selected item is not a course order",
"Course Order Receiver", MessageBoxButton.OK,
MessageBoxImage.Warning);
}
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