Use converter on bound items in combobox

Question

i have a combobox which is bound to a datatable column like this:

ComboBox.DataContext = DataDataTable;                 ComboBox.DisplayMemberPath = DataDataTable.Columns["IDNr"].ToString(); 

The IDNr in the Column always starts with 4 letters followed with the ID Number (ex. BLXF1234) . I need to display the items in Combobox without the Letters (i need 1234 to be displayed in the combobox).

So i wrote a converter :

class IDPrefixValueConverter : IValueConverter {     public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)     {         if (value != null)         {             string s = value.ToString();             if (s.Contains("BL"))             {                 return s.Substring(4);             }             else             {                 return s;             }         }         return "";     }      public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)     {         throw new NotSupportedException();     }        

No, how can i tell the combobox to use the converter to display the items ? i tried this in the Xaml:

ItemsSource="{Binding}"  DisplayMemberPath="{Binding Converter={StaticResource IDPrefixValueConverter}}" 

But still not working ...any ideas ? Thanks

Answer 1

You can modify the ItemTemplate of the ComboBox and use your converter:

<ComboBox ItemsSource="{Binding}">   <ComboBox.ItemTemplate>     <DataTemplate>       <TextBlock Text="{Binding Converter={StaticResource IDPrefixValueConverter}}"/>     </DataTemplate>   </ComboBox.ItemTemplate> </ComboBox> 

Each item is bound to the items in the ItemsSource. By using the converter in the binding you are able to perform the conversion you want.