aistudio-wpf-diagram/AIStudio.Wpf.DiagramDesigner/UserControls/TextControl.xaml

<UserControl x:Class="AIStudio.Wpf.DiagramDesigner.TextControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:s="clr-namespace:AIStudio.Wpf.DiagramDesigner"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800">
    <UserControl.Resources>
        <s:ColorBrushConverter x:Key="ColorBrushConverter" />
        <s:TrueToFalseConverter x:Key="TrueToFalseConverter"/>
        <!--TextBox默认样式-->
        <Style TargetType="{x:Type TextBox}" x:Key="WaterTextBox">
            <Setter Property="Background" Value="Transparent"/>
            <Setter Property="TextWrapping" Value="Wrap"/>
            <Setter Property="Width" Value="Auto"/>
            <Setter Property="HorizontalAlignment" Value="Stretch"/>
            <Setter Property="VerticalAlignment" Value="Stretch"/>
            <Setter Property="BorderThickness" Value="0"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type TextBox}">
                        <Grid x:Name="PART_Root">
                            <Border x:Name="Bg" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                                    BorderBrush="{TemplateBinding BorderBrush}" 
                                    BorderThickness="{TemplateBinding BorderThickness}" 
                                    Background="{TemplateBinding Background}" />
                            <Grid x:Name="PART_InnerGrid">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition  Width="Auto" />
                                    <ColumnDefinition Width="*" />
                                    <ColumnDefinition  Width="Auto" />
                                </Grid.ColumnDefinitions>

                                <!--内容区域-->
                                <ScrollViewer x:Name="PART_ContentHost" BorderThickness="0" Grid.Column="1" IsTabStop="False" Margin="2"
                                          VerticalAlignment="Stretch" Background="{x:Null}" >
                                    <ScrollViewer.Effect>
                                        <DropShadowEffect x:Name="effect" Color="{Binding FontViewModel.TextEffectColor}" ></DropShadowEffect>
                                    </ScrollViewer.Effect>
                                </ScrollViewer>
                                <!--水印-->
                                <TextBlock x:Name="Message"  Padding="{TemplateBinding Padding}" Visibility="Collapsed"
                                       Text="{TemplateBinding s:ControlAttachProperty.Watermark}" Grid.Column="1"
                                       Foreground="{TemplateBinding Foreground}" IsHitTestVisible="False" Opacity="0.5"
                                       HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                       VerticalAlignment="{TemplateBinding VerticalContentAlignment}" Margin="5,2,5,2" />
                            </Grid>
                        </Grid>
                        <ControlTemplate.Triggers>
                            <!--显示水印-->
                            <DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Path=Text}" Value="">
                                <Setter TargetName="Message" Property="Visibility" Value="Visible" />
                            </DataTrigger>
                            <DataTrigger Binding="{Binding FontViewModel.TextEffectColor}" Value="Transparent">
                                <Setter TargetName="PART_ContentHost" Property="Effect" Value="{x:Null}"/>
                            </DataTrigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </UserControl.Resources>
    <Grid IsHitTestVisible="{Binding IsHitTestVisible}">
        <TextBox x:Name="PART_TextBlock"                         
                         Text="{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"  
                         Foreground="{Binding FontViewModel.FontColor,Converter={StaticResource ColorBrushConverter}}"
                         FontSize="{Binding FontViewModel.FontSize}" 
                         FontFamily="{Binding FontViewModel.FontFamily}"  
                         FontWeight="{Binding FontViewModel.FontWeight}"
                         FontStyle="{Binding FontViewModel.FontStyle}"                         
                         FontStretch="{Binding FontViewModel.FontStretch}"
                         TextDecorations="{Binding FontViewModel.TextDecorations}"
                         HorizontalContentAlignment="{Binding FontViewModel.HorizontalAlignment}"
                         VerticalContentAlignment="{Binding FontViewModel.VerticalAlignment}"
                         TextBlock.LineHeight="{Binding FontViewModel.LineHeight}"
                         AcceptsReturn="True"
                         s:ControlAttachProperty.Watermark="{Binding Path=(s:ControlAttachProperty.Watermark),RelativeSource={RelativeSource AncestorType={x:Type s:TextControl}}}"
                         Style="{StaticResource WaterTextBox}" IsReadOnly="True">
      
        </TextBox>
        <TextBox x:Name="PART_ShowText"
                         Text="{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"                                            
                         Foreground="{Binding FontViewModel.FontColor,Converter={StaticResource ColorBrushConverter}}"
                         IsReadOnly="{Binding IsReadOnlyText}"
                         FontSize="{Binding FontViewModel.FontSize}" 
                         FontFamily="{Binding FontViewModel.FontFamily}"  
                         FontWeight="{Binding FontViewModel.FontWeight}"
                         FontStyle="{Binding FontViewModel.FontStyle}"                         
                         FontStretch="{Binding FontViewModel.FontStretch}"
                         TextDecorations="{Binding FontViewModel.TextDecorations}"
                         HorizontalContentAlignment="{Binding FontViewModel.HorizontalAlignment}"
                         VerticalContentAlignment="{Binding FontViewModel.VerticalAlignment}"
                         TextBlock.LineHeight="{Binding FontViewModel.LineHeight}"
                         AcceptsReturn="True"
                         s:ControlAttachProperty.Watermark="{Binding Path=(s:ControlAttachProperty.Watermark),RelativeSource={RelativeSource AncestorType={x:Type s:TextControl}}}"
                         Style="{StaticResource WaterTextBox}" Visibility="Collapsed">
        </TextBox>
       
    </Grid>
</UserControl>