1 <TextBox Text="{Binding SearchInfo, UpdateSourceTrigger=PropertyChanged}" Grid.Row="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="0,0,0,0" MaxLength="20" BorderThickness="0">
2 <TextBox.Resources>
3 <VisualBrush x:Key="HelpBrush" TileMode="None" Opacity="0.3" Stretch="None" AlignmentX="Center">
4 <VisualBrush.Visual>
5 <TextBlock FontStyle="Italic" Text="搜索"/>
6 </VisualBrush.Visual>
7 </VisualBrush>
8 </TextBox.Resources>
9 <TextBox.Style>
10 <Style TargetType="TextBox">
11 <Setter Property="Height" Value="25px"/>
12 <Setter Property="VerticalContentAlignment" Value="Center"/>
13 <Setter Property="HorizontalContentAlignment" Value="Center"/>
14 <Setter Property="Background" Value="Transparent"/>
15 <Style.Triggers>
16 <Trigger Property="Text" Value="{x:Null}">
17 <Setter Property="Background" Value="{StaticResource HelpBrush}"/>
18 </Trigger>
19 <Trigger Property="Text" Value="">
20 <Setter Property="Background" Value="{StaticResource HelpBrush}"/>
21 </Trigger>
22 </Style.Triggers>
23 </Style>
24 </TextBox.Style>
25 </TextBox>
