Как добавить текст водяного знака в текстовое поле в wpf?

Question

Im работает над wpf application.How я могу добавить текст водяного знака к textbox и passwordbox?

<Window x:Class="WpfApplication1.MainWindow" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Title="Platforma Smart School 1.0" Height="580" Width="880" 
    Icon="/WpfApplication4;component/Images/capturennnnnn12_256px%20%282%291.ico"> 

<Grid> 

    <Grid.Background> 
     <ImageBrush ImageSource="/WpfApplication1;component/Images/ 
     hp-colorful-books-hd-105609.jpg" /> 
    </Grid.Background> 

    <Rectangle Height="334" HorizontalAlignment="Left" Margin="608,162,0,0" 
    Name="rectangle1" Stroke="#FFDBD8D8" VerticalAlignment="Top" Width="222" 
    Fill="#FFF0F0F0" /> 

    <Button Height="34" HorizontalAlignment="Left" Margin="630,434,0,0" 
    Name="button1" VerticalAlignment="Top" Width="178" FontSize="13" 
    Foreground="#FF555555" /> 

    <TextBox Height="34" HorizontalAlignment="Left" Margin="630,219,0,0" 
    Name="textBox1" VerticalAlignment="Top" Width="178" FontSize="14" Text="" 
    Foreground="#FF7C7A7A" /> 

    <PasswordBox Height="32" HorizontalAlignment="Left" Margin="630,304,0,0" 
    Name="passwordBox1" VerticalAlignment="Top" Width="178" FontSize="14" 
    FontFamily="Segoe UI"/> 

    <Image Height="134" HorizontalAlignment="Left" Margin="606,12,0,0" 
    Name="image1" Stretch="Fill" VerticalAlignment="Top" Width="224" 
    Source="/WpfApplication1;component/Images/Capture3.PNG" /> 

    <Label Content=" Smart School" Height="31" HorizontalAlignment="Left" 
    Margin="251,498,0,0" Name="label1" VerticalAlignment="Top" Width="227" /> 

</Grid> 

Answer 1

Взгляните на эту SO Question. Второй ответ на создание Attached Property - вот что я хотел бы предложить.

Есть также некоторые расширенные элементы управления WPF, которые могут помочь: http://wpftoolkit.codeplex.com/wikipage?title=WatermarkTextBox

Edit: Добавлен Extended WPF Toolkit ссылки.

Answer 2

Или вы могли бы попробовать этот код

<Grid> 
    <Grid.Resources> 
     <VisualBrush x:Key="LoginHint" Stretch="None" AlignmentX="Left" AlignmentY="Top" > 
       <VisualBrush.Transform> 
        <TranslateTransform X="5" Y="7" /> 
       </VisualBrush.Transform> 
       <VisualBrush.Visual> 
        <Grid HorizontalAlignment="Left"> 
         <TextBlock FontFamily="SEGOEWP" FontSize="10" FontWeight="Normal" 
          HorizontalAlignment="Left" VerticalAlignment="Center"          Foreground="Gray" FontStyle="Italic" Opacity="1"           Text="Enter Username"/> 
        </Grid> 
       </VisualBrush.Visual> 
      </VisualBrush> 
     </Grid.Resources> 
     <Grid.ColumnDefinitions> 
      <ColumnDefinition Width="Auto" /> 
      <ColumnDefinition Width="*" /> 
     </Grid.ColumnDefinitions> 
     <Label x:Name="lblUserName" Content="User Name" Grid.Column="0"        VerticalAlignment="Top" Margin="5"/> 
     <TextBox x:Name="waterMarkTextBox" Width="100" Height="25" Grid.Column="1" 
     VerticalAlignment="Top" HorizontalAlignment="Left" Margin="5"> 
      <TextBox.Style> 
      <Style TargetType="{x:Type TextBox}"> 
       <Setter Property="Background" Value="Transparent"/> 
       <Style.Triggers> 
        <DataTrigger Binding="{Binding ElementName=waterMarkTextBox,Path=Text}"      Value="" > 
         <Setter Property="Background" Value="{StaticResource LoginHint}"/> 
        </DataTrigger> 
       </Style.Triggers> 
       </Style> 
      </TextBox.Style> 
     </TextBox> 
    </Grid> 

Answer 3

MahApps.Metro имеет встроенный контроль водяных знаков, и это довольно простой в использовании. Он работает с PasswordBox.

<AdornerDecorator> 
      <PasswordBox Name="password" 
        Width="200" 
        HorizontalAlignment="Right"> 
       <Controls:TextBoxHelper.Watermark>Password</Controls:TextBoxHelper.Watermark> 
      </PasswordBox> 
    </AdornerDecorator>