JYHB.SlnMesnac/SlnMesnac.WPF/App.xaml

<Application x:Class="SlnMesnac.WPF.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:SlnMesnac.WPF"
             StartupUri="MainWindow.xaml" DispatcherUnhandledException="Application_DispatcherUnhandledException">
    <Application.Resources>
        
        <ResourceDictionary>
            <Style x:Key="TextBoxStyle" TargetType="TextBox">
                <Setter Property="BorderThickness" Value="0"/>
                <Setter Property="BorderBrush" Value="Transparent"/>
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="TextBox">
                            <Grid>
                                <ScrollViewer x:Name="PART_ContentHost" Margin="0" VerticalAlignment="Center"/>
                                <Rectangle StrokeThickness="0" Height="1" VerticalAlignment="Bottom" Fill="Gray"/>
                            </Grid>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
            
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="Templates/style/resourceStyle.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>