Question

I have a custom ItemTemplate for a ListBox and I need to “bind” a TextBlock to some special method / property.

My ListBox Source is an ObservableCollection<SearchResultItem>. SearchResultItem containing some properties.

The text need to change based on the value of another object. E.G if this object equals “foo” I need the text value to call the method GetProperty("foo") on the SearchResultItem to get the correct value.

Here is a sample of code:

<DataTemplate>
..
//Here is a Label bound to the Date Property of the SearchResultItem
<Label Margin="2,2,2,0" Grid.Row="0" Grid.Column="2" Content="{Binding Path=Date}" HorizontalAlignment="Right" HorizontalContentAlignment="Right" />
//Here is the textblock that needs to call the method with the parameter based on the value of the other object.
<TextBlock Margin="2,2,2,0" TextTrimming="CharacterEllipsis"  Grid.Row="0" Grid.Column="1" Text="I need some help there" HorizontalAlignment="Left" VerticalAlignment="Center" Foreground="Black"/>
..
</DataTemplate>

Do you have any idea on how to do that or a better way to do it?

Edit:

-Let’s assume SearchResultItem comes from an external library and only exposes the GetProperty method.

-Let’s say the “foo” value comes from ConfigurationManager.AppSettings["propertyName"]; if it helps.

Answer 1

OK, because your properties never change, here’s one solution. You can do this via another property on your SearchResultItem class:

public string MyTextBinding
{
    get 
    {
        return myDictionary.ContainsKey("foo") ? return myDictionary["foo"] : return "myDictionary doesn't contain foo"; 
    }
}

Then just bind your textbox to this property:

<DataTemplate>    
    <Label Margin="2,2,2,0" Grid.Row="0" Grid.Column="2" Content="{Binding Path=Date}" HorizontalAlignment="Right" HorizontalContentAlignment="Right" />
    <TextBlock Margin="2,2,2,0" TextTrimming="CharacterEllipsis"  Grid.Row="0" Grid.Column="1" Text="{Binding Path=MyTextBinding, Mode=OneWay}" HorizontalAlignment="Left" VerticalAlignment="Center" Foreground="Black"/>
</DataTemplate>