vue-java-tutorials/CSharp/WPFTutorial/Message-MainApplication/App.xaml

<dryIoc:PrismApplication x:Class="Message_MainApplication.App"
                         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                         xmlns:dryIoc="http://prismlibrary.com/">
    <dryIoc:PrismApplication.Resources>

    </dryIoc:PrismApplication.Resources>
</dryIoc:PrismApplication>