如何使用 Expression Blend 在 WPF 中编辑 DatePicker 的水印
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【中文标题】如何使用 Expression Blend 在 WPF 中编辑 DatePicker 的水印【英文标题】：How do i edit the watermark for a DatePicker in WPF using Expression Blend 【发布时间】：2014-08-15 04:49:13 【问题描述】：我使用 DatePicker 创建了一个简单的 Expression Blend 4 项目。我编辑了 DatePicker 的模板，包括它的 DatePickerTextBox，将水印文本从“选择日期”更改为“dd/mm/yyyy”。 Blend 中生成的 XAML 将样式应用于原始 DatePicker，并且此样式存储为 Window.Resources 中的资源。但是，对水印文本所做的编辑不会生效。有任何想法吗？谢谢。 （请注意，我不想诉诸代码，我想了解如何使用 Blend 来实现。）。这是窗口的 XAML：
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" mc:Ignorable="d"
x:Class="HelloWorldBlen.MainWindow"
x:Name="Window"
Title="MainWindow"
Width="640" Height="480">
<Window.Resources>
<Style x:Key="DatePickerStyle1" TargetType="x:Type DatePicker">
<Setter Property="Foreground" Value="#FF333333"/>
<Setter Property="IsTodayHighlighted" Value="True"/>
<Setter Property="SelectedDateFormat" Value="Short"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Padding" Value="2"/>
<Setter Property="BorderBrush">
<Setter.Value>
<LinearGradientBrush EndPoint=".5,0" StartPoint=".5,1">
<GradientStop Color="#FFA3AEB9" Offset="0"/>
<GradientStop Color="#FF8399A9" Offset="0.375"/>
<GradientStop Color="#FF718597" Offset="0.375"/>
<GradientStop Color="#FF617584" Offset="1"/>
</LinearGradientBrush>
</Setter.Value>
</Setter>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="HorizontalContentAlignment" Value="Stretch"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="x:Type DatePicker">
<Border BorderBrush="TemplateBinding BorderBrush" BorderThickness="TemplateBinding BorderThickness" Background="TemplateBinding Background" Padding="TemplateBinding Padding">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_DisabledVisual"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid x:Name="PART_Root" HorizontalAlignment="TemplateBinding HorizontalContentAlignment" VerticalAlignment="TemplateBinding VerticalContentAlignment">
<Grid.Resources>
<SolidColorBrush x:Key="DisabledBrush" Color="#A5FFFFFF"/>
<ControlTemplate x:Key="DropDownButtonTemplate" TargetType="x:Type Button">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="MouseOver"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="Pressed"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver">
<Storyboard>
<ColorAnimation Duration="0" To="#FF448DCA" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)" Storyboard.TargetName="Background"/>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[3].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#7FFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[2].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#CCFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[1].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#F2FFFFFF"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)" Storyboard.TargetName="Background">
<SplineColorKeyFrame KeyTime="0" Value="#FF448DCA"/>
</ColorAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="Highlight">
<SplineDoubleKeyFrame KeyTime="0" Value="1"/>
</DoubleAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[1].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#EAFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[2].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#C6FFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[3].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#6BFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[0].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#F4FFFFFF"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid Background="#11FFFFFF" FlowDirection="LeftToRight" HorizontalAlignment="Center" Height="18" Margin="0" VerticalAlignment="Center" Width="19">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="23*"/>
<RowDefinition Height="19*"/>
<RowDefinition Height="19*"/>
<RowDefinition Height="19*"/>
</Grid.RowDefinitions>
<Border x:Name="Highlight" BorderBrush="#FF45D6FA" BorderThickness="1" Grid.ColumnSpan="4" CornerRadius="0,0,1,1" Margin="-1" Opacity="0" Grid.Row="0" Grid.RowSpan="4"/>
<Border x:Name="Background" BorderBrush="#FFFFFFFF" BorderThickness="1" Background="#FF1F3B53" Grid.ColumnSpan="4" CornerRadius=".5" Margin="0,-1,0,0" Opacity="1" Grid.Row="1" Grid.RowSpan="3"/>
<Border x:Name="BackgroundGradient" BorderBrush="#BF000000" BorderThickness="1" Grid.ColumnSpan="4" CornerRadius=".5" Margin="0,-1,0,0" Opacity="1" Grid.Row="1" Grid.RowSpan="3">
<Border.Background>
<LinearGradientBrush EndPoint=".7,1" StartPoint=".7,0">
<GradientStop Color="#FFFFFFFF" Offset="0"/>
<GradientStop Color="#F9FFFFFF" Offset="0.375"/>
<GradientStop Color="#E5FFFFFF" Offset="0.625"/>
<GradientStop Color="#C6FFFFFF" Offset="1"/>
</LinearGradientBrush>
</Border.Background>
</Border>
<Rectangle Grid.ColumnSpan="4" Grid.RowSpan="1" StrokeThickness="1">
<Rectangle.Fill>
<LinearGradientBrush EndPoint="0.3,-1.1" StartPoint="0.46,1.6">
<GradientStop Color="#FF4084BD"/>
<GradientStop Color="#FFAFCFEA" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Fill>
<Rectangle.Stroke>
<LinearGradientBrush EndPoint="0.48,-1" StartPoint="0.48,1.25">
<GradientStop Color="#FF494949"/>
<GradientStop Color="#FF9F9F9F" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Stroke>
</Rectangle>
<Path Grid.ColumnSpan="4" Grid.Column="0" Data="M11.426758,8.4305077 L11.749023,8.4305077 L11.749023,16.331387 L10.674805,16.331387 L10.674805,10.299648 L9.0742188,11.298672 L9.0742188,10.294277 C9.4788408,10.090176 9.9094238,9.8090878 10.365967,9.4510155 C10.82251,9.0929432 11.176106,8.7527733 11.426758,8.4305077 z M14.65086,8.4305077 L18.566387,8.4305077 L18.566387,9.3435936 L15.671368,9.3435936 L15.671368,11.255703 C15.936341,11.058764 16.27293,10.960293 16.681133,10.960293 C17.411602,10.960293 17.969301,11.178717 18.354229,11.615566 C18.739157,12.052416 18.931622,12.673672 18.931622,13.479336 C18.931622,15.452317 18.052553,16.438808 16.294415,16.438808 C15.560365,16.438808 14.951641,16.234707 14.468243,15.826504 L14.881817,14.929531 C15.368796,15.326992 15.837872,15.525723 16.289043,15.525723 C17.298809,15.525723 17.803692,14.895514 17.803692,13.635098 C17.803692,12.460618 17.305971,11.873379 16.310528,11.873379 C15.83071,11.873379 15.399232,12.079271 15.016094,12.491055 L14.65086,12.238613 z" Fill="#FF2F2F2F" HorizontalAlignment="Center" Margin="4,3,4,3" Grid.Row="1" Grid.RowSpan="3" RenderTransformOrigin="0.5,0.5" Stretch="Fill" VerticalAlignment="Center"/>
<Ellipse Grid.ColumnSpan="4" Fill="#FFFFFFFF" HorizontalAlignment="Center" Height="3" StrokeThickness="0" VerticalAlignment="Center" Width="3"/>
<Border x:Name="DisabledVisual" BorderBrush="#B2FFFFFF" BorderThickness="1" Grid.ColumnSpan="4" CornerRadius="0,0,.5,.5" Opacity="0" Grid.Row="0" Grid.RowSpan="4"/>
</Grid>
</Grid>
</ControlTemplate>
</Grid.Resources>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Button x:Name="PART_Button" Grid.Column="1" Foreground="TemplateBinding Foreground" Focusable="False" HorizontalAlignment="Left" Margin="3,0,3,0" Grid.Row="0" Template="StaticResource DropDownButtonTemplate" VerticalAlignment="Top" Width="20"/>
<DatePickerTextBox x:Name="PART_TextBox" Grid.Column="0" Foreground="TemplateBinding Foreground" Focusable="TemplateBinding Focusable" HorizontalContentAlignment="Stretch" Grid.Row="0" VerticalContentAlignment="Stretch" Style="DynamicResource DatePickerTextBoxStyle1"/>
<Grid x:Name="PART_DisabledVisual" Grid.ColumnSpan="2" Grid.Column="0" IsHitTestVisible="False" Opacity="0" Grid.Row="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Rectangle Grid.Column="0" Fill="#A5FFFFFF" RadiusY="1" Grid.Row="0" RadiusX="1"/>
<Rectangle Grid.Column="1" Fill="#A5FFFFFF" Height="18" Margin="3,0,3,0" RadiusY="1" Grid.Row="0" RadiusX="1" Width="19"/>
<Popup x:Name="PART_Popup" AllowsTransparency="True" Placement="Bottom" PlacementTarget="Binding ElementName=PART_TextBox" StaysOpen="False"/>
</Grid>
</Grid>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="DatePickerTextBoxStyle1" TargetType="x:Type DatePickerTextBox">
<Setter Property="Foreground" Value="DynamicResource x:Static SystemColors.WindowTextBrushKey"/>
<Setter Property="Background" Value="DynamicResource x:Static SystemColors.WindowBrushKey"/>
<Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst"/>
<Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="x:Type DatePickerTextBox">
<Grid>
<Grid.Resources>
<SolidColorBrush x:Key="WatermarkBrush" Color="#FFAAAAAA"/>
</Grid.Resources>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="MouseOver"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver">
<Storyboard>
<ColorAnimation Duration="0" To="#FF99C1E2" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" Storyboard.TargetName="ContentElement"/>
<ColorAnimation Duration="0" To="#FF99C1E2" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" Storyboard.TargetName="watermark_decorator"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="WatermarkStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Unwatermarked"/>
<VisualState x:Name="Watermarked">
<Storyboard>
<DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="ContentElement"/>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_Watermark"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Unfocused"/>
<VisualState x:Name="Focused">
<Storyboard>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="FocusVisual"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="Border" BorderBrush="TemplateBinding BorderBrush" BorderThickness="TemplateBinding BorderThickness" Background="TemplateBinding Background" CornerRadius="1" Opacity="1" Padding="TemplateBinding Padding">
<Grid x:Name="WatermarkContent" HorizontalAlignment="TemplateBinding HorizontalContentAlignment" VerticalAlignment="TemplateBinding VerticalContentAlignment">
<Border x:Name="ContentElement" BorderBrush="#FFFFFFFF" BorderThickness="1"/>
<Border x:Name="watermark_decorator" BorderBrush="#FFFFFFFF" BorderThickness="1">
<ContentControl x:Name="PART_Watermark" Focusable="False" IsHitTestVisible="False" Opacity="0" Padding="2" Content="dd/mm/yyyy"/>
</Border>
<ScrollViewer x:Name="PART_ContentHost" HorizontalContentAlignment="TemplateBinding HorizontalContentAlignment" Margin="0" VerticalContentAlignment="TemplateBinding VerticalContentAlignment"/>
<Border x:Name="FocusVisual" BorderBrush="#FF45D6FA" CornerRadius="1" IsHitTestVisible="False" Opacity="0"/>
</Grid>
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid x:Name="LayoutRoot">
<DatePicker VerticalAlignment="Top" Margin="250,112,272.36,0" d:LayoutOverrides="Width" Style="DynamicResource DatePickerStyle1"/>
</Grid>
【问题讨论】：
【参考方案1】：当我还需要使用不同的水印时，我遇到了这个问题和答案。 （在我的例子中是一个空水印。）接受的答案中的代码太长太复杂，以至于我没有真正考虑使用它。 Jón Arnar 的简短回答在某些情况下有效，但在我的情况下却没有。 （加载窗口时，日期选择器为空。但是，一旦我将空值加载到日期选择器控件中，标准水印就会再次出现。这让我再次查看接受的答案，我缩短了它，所以它只是删除水印，没有别的（嗯......）。对于像我在这里搜索的人来说，这是带有一些解释的较短版本：
<UserControl.Resources>
<Style TargetType="DatePickerTextBox">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="x:Type DatePickerTextBox">
<Grid>
<Grid.Resources>
<SolidColorBrush x:Key="WatermarkBrush" Color="#FFAAAAAA"/>
</Grid.Resources>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="MouseOver"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver">
<Storyboard>
<ColorAnimation Duration="0" To="#FF99C1E2" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" Storyboard.TargetName="ContentElement"/>
<ColorAnimation Duration="0" To="#FF99C1E2" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" Storyboard.TargetName="watermark_decorator"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="WatermarkStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Unwatermarked"/>
<VisualState x:Name="Watermarked">
<Storyboard>
<DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="ContentElement"/>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_Watermark"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Unfocused"/>
<VisualState x:Name="Focused">
<Storyboard>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="FocusVisual"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="Border" BorderBrush="TemplateBinding BorderBrush" BorderThickness="TemplateBinding BorderThickness" Background="TemplateBinding Background" CornerRadius="1" Opacity="1" Padding="TemplateBinding Padding">
<Grid x:Name="WatermarkContent" HorizontalAlignment="TemplateBinding HorizontalContentAlignment" VerticalAlignment="TemplateBinding VerticalContentAlignment">
<Border x:Name="ContentElement" BorderBrush="#FFFFFFFF" BorderThickness="1"/>
<Border x:Name="watermark_decorator" BorderBrush="#FFFFFFFF" BorderThickness="1">
<ContentControl x:Name="PART_Watermark" Focusable="False" IsHitTestVisible="False" Opacity="0" Padding="2">
<ContentControl.Template>
<ControlTemplate>
<TextBlock Text=""/>
</ControlTemplate>
</ContentControl.Template>
</ContentControl>
</Border>
<ScrollViewer x:Name="PART_ContentHost" HorizontalContentAlignment="TemplateBinding HorizontalContentAlignment" Margin="0" VerticalContentAlignment="TemplateBinding VerticalContentAlignment"/>
<Border x:Name="FocusVisual" BorderBrush="#FF45D6FA" CornerRadius="1" IsHitTestVisible="False" Opacity="0"/>
</Grid>
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</UserControl.Resources>
我个人在用户控件中使用它，但对于窗口<Window.Resources> 也可以。该元素作为子元素直接放置在UserControl 或Window 的开始标记之后。关键部分是<TextBlock Text=""/>。因为我想要一个空水印，所以我指定一个空字符串。
这是我能够剥离的代码量。是否可以删除更多？如果您知道或直接编辑此答案，请发表评论。
我希望这对下一个寻找最佳解决方案的人有所帮助。
【讨论】：
为我工作！这应该是公认的答案。【参考方案2】：编辑：
修复了您评论中描述的问题。此样式修改了WaterMark's ControlTemplate 并按预期工作。
<Window x:Class="WpfApplication4.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<Style x:Key="DatePickerStyle1" TargetType="x:Type DatePicker">
<Setter Property="Foreground" Value="#FF333333"/>
<Setter Property="IsTodayHighlighted" Value="True"/>
<Setter Property="SelectedDateFormat" Value="Short"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Padding" Value="2"/>
<Setter Property="BorderBrush">
<Setter.Value>
<LinearGradientBrush EndPoint=".5,0" StartPoint=".5,1">
<GradientStop Color="#FFA3AEB9" Offset="0"/>
<GradientStop Color="#FF8399A9" Offset="0.375"/>
<GradientStop Color="#FF718597" Offset="0.375"/>
<GradientStop Color="#FF617584" Offset="1"/>
</LinearGradientBrush>
</Setter.Value>
</Setter>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="HorizontalContentAlignment" Value="Stretch"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="x:Type DatePicker">
<Border BorderBrush="TemplateBinding BorderBrush" BorderThickness="TemplateBinding BorderThickness" Background="TemplateBinding Background" Padding="TemplateBinding Padding">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_DisabledVisual"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid x:Name="PART_Root" HorizontalAlignment="TemplateBinding HorizontalContentAlignment" VerticalAlignment="TemplateBinding VerticalContentAlignment">
<Grid.Resources>
<SolidColorBrush x:Key="DisabledBrush" Color="#A5FFFFFF"/>
<ControlTemplate x:Key="DropDownButtonTemplate" TargetType="x:Type Button">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="MouseOver"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="Pressed"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver">
<Storyboard>
<ColorAnimation Duration="0" To="#FF448DCA" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)" Storyboard.TargetName="Background"/>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[3].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#7FFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[2].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#CCFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[1].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#F2FFFFFF"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)" Storyboard.TargetName="Background">
<SplineColorKeyFrame KeyTime="0" Value="#FF448DCA"/>
</ColorAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="Highlight">
<SplineDoubleKeyFrame KeyTime="0" Value="1"/>
</DoubleAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[1].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#EAFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[2].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#C6FFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[3].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#6BFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[0].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#F4FFFFFF"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid Background="#11FFFFFF" FlowDirection="LeftToRight" HorizontalAlignment="Center" Height="18" Margin="0" VerticalAlignment="Center" Width="19">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="23*"/>
<RowDefinition Height="19*"/>
<RowDefinition Height="19*"/>
<RowDefinition Height="19*"/>
</Grid.RowDefinitions>
<Border x:Name="Highlight" BorderBrush="#FF45D6FA" BorderThickness="1" Grid.ColumnSpan="4" CornerRadius="0,0,1,1" Margin="-1" Opacity="0" Grid.Row="0" Grid.RowSpan="4"/>
<Border x:Name="Background" BorderBrush="#FFFFFFFF" BorderThickness="1" Background="#FF1F3B53" Grid.ColumnSpan="4" CornerRadius=".5" Margin="0,-1,0,0" Opacity="1" Grid.Row="1" Grid.RowSpan="3"/>
<Border x:Name="BackgroundGradient" BorderBrush="#BF000000" BorderThickness="1" Grid.ColumnSpan="4" CornerRadius=".5" Margin="0,-1,0,0" Opacity="1" Grid.Row="1" Grid.RowSpan="3">
<Border.Background>
<LinearGradientBrush EndPoint=".7,1" StartPoint=".7,0">
<GradientStop Color="#FFFFFFFF" Offset="0"/>
<GradientStop Color="#F9FFFFFF" Offset="0.375"/>
<GradientStop Color="#E5FFFFFF" Offset="0.625"/>
<GradientStop Color="#C6FFFFFF" Offset="1"/>
</LinearGradientBrush>
</Border.Background>
</Border>
<Rectangle Grid.ColumnSpan="4" Grid.RowSpan="1" StrokeThickness="1">
<Rectangle.Fill>
<LinearGradientBrush EndPoint="0.3,-1.1" StartPoint="0.46,1.6">
<GradientStop Color="#FF4084BD"/>
<GradientStop Color="#FFAFCFEA" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Fill>
<Rectangle.Stroke>
<LinearGradientBrush EndPoint="0.48,-1" StartPoint="0.48,1.25">
<GradientStop Color="#FF494949"/>
<GradientStop Color="#FF9F9F9F" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Stroke>
</Rectangle>
<Path Grid.ColumnSpan="4" Grid.Column="0" Data="M11.426758,8.4305077 L11.749023,8.4305077 L11.749023,16.331387 L10.674805,16.331387 L10.674805,10.299648 L9.0742188,11.298672 L9.0742188,10.294277 C9.4788408,10.090176 9.9094238,9.8090878 10.365967,9.4510155 C10.82251,9.0929432 11.176106,8.7527733 11.426758,8.4305077 z M14.65086,8.4305077 L18.566387,8.4305077 L18.566387,9.3435936 L15.671368,9.3435936 L15.671368,11.255703 C15.936341,11.058764 16.27293,10.960293 16.681133,10.960293 C17.411602,10.960293 17.969301,11.178717 18.354229,11.615566 C18.739157,12.052416 18.931622,12.673672 18.931622,13.479336 C18.931622,15.452317 18.052553,16.438808 16.294415,16.438808 C15.560365,16.438808 14.951641,16.234707 14.468243,15.826504 L14.881817,14.929531 C15.368796,15.326992 15.837872,15.525723 16.289043,15.525723 C17.298809,15.525723 17.803692,14.895514 17.803692,13.635098 C17.803692,12.460618 17.305971,11.873379 16.310528,11.873379 C15.83071,11.873379 15.399232,12.079271 15.016094,12.491055 L14.65086,12.238613 z" Fill="#FF2F2F2F" HorizontalAlignment="Center" Margin="4,3,4,3" Grid.Row="1" Grid.RowSpan="3" RenderTransformOrigin="0.5,0.5" Stretch="Fill" VerticalAlignment="Center"/>
<Ellipse Grid.ColumnSpan="4" Fill="#FFFFFFFF" HorizontalAlignment="Center" Height="3" StrokeThickness="0" VerticalAlignment="Center" Width="3"/>
<Border x:Name="DisabledVisual" BorderBrush="#B2FFFFFF" BorderThickness="1" Grid.ColumnSpan="4" CornerRadius="0,0,.5,.5" Opacity="0" Grid.Row="0" Grid.RowSpan="4"/>
</Grid>
</Grid>
</ControlTemplate>
</Grid.Resources>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Button x:Name="PART_Button" Grid.Column="1" Foreground="TemplateBinding Foreground" Focusable="False" HorizontalAlignment="Left" Margin="3,0,3,0" Grid.Row="0" Template="StaticResource DropDownButtonTemplate" VerticalAlignment="Top" Width="20"/>
<DatePickerTextBox x:Name="PART_TextBox" Grid.Column="0" Focusable="TemplateBinding Focusable" HorizontalContentAlignment="Stretch" Grid.Row="0" VerticalContentAlignment="Stretch">
<DatePickerTextBox.Style>
<Style TargetType="DatePickerTextBox">
<Setter Property="Foreground" Value="DynamicResource x:Static SystemColors.WindowTextBrushKey"/>
<Setter Property="Background" Value="DynamicResource x:Static SystemColors.WindowBrushKey"/>
<Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst"/>
<Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="x:Type DatePickerTextBox">
<Grid>
<Grid.Resources>
<SolidColorBrush x:Key="WatermarkBrush" Color="#FFAAAAAA"/>
</Grid.Resources>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="MouseOver"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver">
<Storyboard>
<ColorAnimation Duration="0" To="#FF99C1E2" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" Storyboard.TargetName="ContentElement"/>
<ColorAnimation Duration="0" To="#FF99C1E2" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" Storyboard.TargetName="watermark_decorator"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="WatermarkStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Unwatermarked"/>
<VisualState x:Name="Watermarked">
<Storyboard>
<DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="ContentElement"/>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_Watermark"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Unfocused"/>
<VisualState x:Name="Focused">
<Storyboard>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="FocusVisual"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="Border" BorderBrush="TemplateBinding BorderBrush" BorderThickness="TemplateBinding BorderThickness" Background="TemplateBinding Background" CornerRadius="1" Opacity="1" Padding="TemplateBinding Padding">
<Grid x:Name="WatermarkContent" HorizontalAlignment="TemplateBinding HorizontalContentAlignment" VerticalAlignment="TemplateBinding VerticalContentAlignment">
<Border x:Name="ContentElement" BorderBrush="#FFFFFFFF" BorderThickness="1"/>
<Border x:Name="watermark_decorator" BorderBrush="#FFFFFFFF" BorderThickness="1">
<ContentControl x:Name="PART_Watermark" Focusable="False" IsHitTestVisible="False" Opacity="0" Padding="2">
<ContentControl.Template>
<ControlTemplate>
<TextBlock Text="dd/mm/yyyy"/>
</ControlTemplate>
</ContentControl.Template>
</ContentControl>
</Border>
<ScrollViewer x:Name="PART_ContentHost" HorizontalContentAlignment="TemplateBinding HorizontalContentAlignment" Margin="0" VerticalContentAlignment="TemplateBinding VerticalContentAlignment"/>
<Border x:Name="FocusVisual" BorderBrush="#FF45D6FA" CornerRadius="1" IsHitTestVisible="False" Opacity="0"/>
</Grid>
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</DatePickerTextBox.Style>
</DatePickerTextBox>
<Grid x:Name="PART_DisabledVisual" Grid.ColumnSpan="2" Grid.Column="0" IsHitTestVisible="False" Opacity="0" Grid.Row="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Rectangle Grid.Column="0" Fill="#A5FFFFFF" RadiusY="1" Grid.Row="0" RadiusX="1"/>
<Rectangle Grid.Column="1" Fill="#A5FFFFFF" Height="18" Margin="3,0,3,0" RadiusY="1" Grid.Row="0" RadiusX="1" Width="19"/>
<Popup x:Name="PART_Popup" AllowsTransparency="True" Placement="Bottom" PlacementTarget="Binding ElementName=PART_TextBox" StaysOpen="False"/>
</Grid>
</Grid>
</Border>
<ControlTemplate.Triggers>
<DataTrigger Binding="Binding Source=x:Static SystemParameters.HighContrast" Value="false">
<Setter Property="Foreground" TargetName="PART_TextBox" Value="Binding Foreground, RelativeSource=RelativeSource TemplatedParent"/>
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid>
<DatePicker HorizontalAlignment="Left" VerticalAlignment="Top" Style="DynamicResource DatePickerStyle1"/>
</Grid>
</Window>
【讨论】：
我使用了 Expression Blend 4，然后在 Visual Studio 中玩弄了这个项目。你的风格真的很成功！谢谢。 抱歉，很遗憾，您提供的样式只会更改“PART_TextBox”的“Text”属性，因此一旦您开始输入，文本就不会消失。它不会改变水印。 @arlvin 我会再看更多 嘿！感谢更新。这正是我正在寻找的。span> 【参考方案3】：<DatePicker>
<DatePicker.Resources>
<Style TargetType="DatePickerTextBox">
<Setter Property="Text" Value="Watermark Text"/>
</Style>
</DatePicker.Resources>
</DatePicker>
更多信息请见： http://www.admindiaries.com/change-datepicker-watermark-in-wpf/
【讨论】：
这将删除在 DatePickerTextBox 上设置的其他样式，因此您可以放松前景色和后色并控制模板视觉样式。 我注意到当文本被更改然后再次删除时（空课本，原来的'选择日期'又出现了）。【参考方案4】： private void OnUserControlLoaded(object sender, RoutedEventArgs e)
setDateTimeWaterMark();
private void setDateTimeWaterMark()
var dp = dpDob as DatePicker;
if (dp == null) return;
if (VisualTreeHelper.GetChildrenCount(dp) == 1)
var border = VisualTreeHelper.GetChild(dp, 0);
if (border == null) return;
var grid = VisualTreeHelper.GetChild(border, 0);
if (grid == null) return;
DatePickerTextBox txb = VisualTreeHelper.GetChild(grid, 1) as DatePickerTextBox;
if (txb == null) return;
txb.Text = "MM/DD/YYYY";
【讨论】：
请解释您的答案，而不是仅仅输入一些代码。它可以帮助 OP，并且会改善您的答案。以上是关于如何使用 Expression Blend 在 WPF 中编辑 DatePicker 的水印的主要内容，如果未能解决你的问题，请参考以下文章
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