wpf - Databinding to a string derived from the Count of a List -

I have TextBlock , I get it from the list & lt; T & gt; . like.

I can find it this way:

  & lt; TextBlockName = "tbAlerts" Text = "{Binding Path = Alert. Calculation}" / & gt;   
 Where the alert is a  list & lt; String & gt; , and it shows the right thing but, when the count is zero then I want to display "no alert".  
 I thought it would be a way to expose an additional string property to increase the list ???? Call it  CountText  â ???? Which exits the desired string, when it is zero, "no alert" can come out, and when "code> calculation == 1  is" a warning. "Will this work?  < P> If I do this, then how do I get a change in count as a result of  PropertyTanged  event for Code code, so that it can be updated in WPF UI?  
 Is the preferred way of getting that effect? ​​  
 
 
 Ace One way to do this is to return a string which is zero and / or any other number that you want to add custom text to update the UI when there is a change in count, whenever an item is added / Alert is removed from the list, you will need to call the marked handler with the property in the list.  
  Public Class WarningCount Converter: IValueConverter {Public Object Conver T (object value, Type type type, object parameter, Kalcrinfo culture) {string result = null; If (value! = Null) {int count = System.Convert.ToInt32 (value); If (value == 0) result = "no alert"; And result = count.ToString (); } Return results; } Public Object Convertback (type object type, type type, object parameter, culture input culture) {new naturally exposed (return); }}   
  & lt; UserControl.Resources & gt; & Lt; Local: AlertConverter Converter x: key = "AlertConnectConver" /> & Lt; /UserControl.Resources> & Lt; TextBlock x: Name = "tbAlerts" text = "{Biting Alert. Calculation, Converter = {Static Resources AlertConverter Converter}}" />