user38/WhiteList/ChangePriority.xaml

<Window x:Class="WhiteList.ChangePriority"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WhiteList"
        mc:Ignorable="d"
         Title="Приятный шелест" Icon="Images/Приятный шелест.png" MinHeight="200" MinWidth="350" MaxHeight="200" MaxWidth="350">
    <Grid>
        <StackPanel>
            <TextBox Name="TextBoxNewPriority" TextChanged="TextBoxNewPriority_TextChanged"></TextBox>
            <Button Click="Save_Click">
                <TextBlock>Сохранить</TextBlock>
            </Button>
        </StackPanel>
    </Grid>
</Window>