Change the value of a wpf static resource

Question

How can i change the value of a WPF static resource at runtime?

I have the following resources

<UserControl.Resources>
    <sys:String x:Key="LengthFormat">#.# mm</sys:String>
    <sys:String x:Key="AreaFormat">#.# mm²</sys:String>
    <sys:String x:Key="InertiaFormat">#.# mm⁴</sys:String>
</UserControl.Resources>

which some textblocks reference

<TextBlock Grid.Row="2" Grid.Column="1" 
 Text="{Binding Path=Breadth, StringFormat={StaticResource ResourceKey=LengthFormat}}" />

then depending on the object to be bound to the control i would like to change the formats. I have set up properties in the control as follows:

public string LengthFormat
{
    set
    {
        this.Resources["LengthFormat"] = value;
    }
}
public string AreaFormat
{
    set
    {
        this.Resources["AreaFormat"] = value;
    }
}
public string InertiaFormat
{
    set
    {
        this.Resources["InertiaFormat"] = value;
    }
}

then before binding i set each string.

However it doesn't work, anyone suggest whynot?

Cheers

Answer 1

Actually it works just fine. But the UI isn't updated, as the resource keys aren't being observed.

You shouldn't use static resources, if you want bindings that can change. Use regular bindings instead, with INotifyPropertyChanged on the properties, allowing the UI to observe changes.