How to sort keys in ResourceDictionary in xaml in wpf?

Hi EveryOne,

              I need to sort the keys in ResourceDictionary in xaml. I tried with sorting using SortedList and stored using XamlWriter.Save. but it storing in Unsorted Order in xaml. Can any one help me to solve the problem?

Ex:

        <ResourceDictionary>

              <sys:string x:Key="Subtraction">Subtraction</sys:string>

              <sys:string x:Key="Add">ADD</sys:string>

              <sys:string x:Key="Multiply">Multiplication</sys:string>

        </ResourceDictionary>

Thanks,

Stalin Raj.