Now that we've found out a little about resources and how useful they can be for storing things (and more importantly, reducing repetition in our Xaml) lets look at how we can reuse them across multiple Xaml files.

Enter the ResourceDictionary:

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:sys="clr-namespace:System;assembly=mscorlib"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
    
    <sys:DateTime x:Key="date1">20070711</sys:DateTime>
    <sys:DateTime x:Key="date2">20071225</sys:DateTime>
    
</ResourceDictionary>

Wow! Now we can easily reuse our two dates (!? I know, I know) by referencing our resource dictionary in any other Xaml file:

<Page.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="MyDictionary.xaml" />
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</Page.Resources>

Note that the dictionaries are merged. So if you have two things in with the same key, the last one wins.