ObjectDataProvider

<Window.Resources> 
    <ObjectDataProvider ObjectType="{x:Type local:TemperatureScale}" 
        MethodName="ConvertTemp" x:Key="convertTemp"> 
        <ObjectDataProvider.MethodParameters> 
            <system:Double>0</system:Double> 
             <local:TempType>Celsius</local:TempType> 
        </ObjectDataProvider.MethodParameters> 
    </ObjectDataProvider> 
</Window.Resources>