Question

我被要求在现有的DateTimePicker控件周围创建一个hack。通常，日期/时间选择器具有日历的精彩图像，然后是旁边的文本框，用于显示实际日期。用户可以单击图像并向其显示弹出日历，选择后，日期将刷新到文本框区域。

我遇到的问题是其他设计师不喜欢日历图形，只想要一个纯文本框控件，但如果用户双击，打开弹出日历，获取日期并刷新它。由于在S / O上找到了其他帮助，我对此非常接近。

所以，要描述我的控件模板，并保持简单（非自定义控件，除非我需要根据建议）。控件模板基于文本框控件。我们为文本框设置了PART_ContentHost的边框，然后是标准日历控件的弹出框。

对于控件模板触发器，我有一个链接到ScrollViewer（文本框输入区域）的MouseDoubleClick事件。如果已触发，则将弹出窗口的IsOpen设置为true并公开日历。这很好。

现在，完成它。如果用户从日历中选择日期，则下一个触发器将关闭弹出窗口（IsOpen设置为false）。这也有效。

我的问题。我还希望在选择时选择日期，并将其ToString（）日期表示放入ScrollViewer.Content（x：Name =“PART_ContentHost）。

<ControlTemplate TargetType="{x:Type TextBox}" x:Key="CTTextBox" >
   <StackPanel>
      <Border x:Name="targetBorder" 
         BorderBrush="{TemplateBinding BorderBrush}"
         SnapsToDevicePixels="true">

         <ScrollViewer x:Name="PART_ContentHost"
            Background="{TemplateBinding Background}"
            BorderBrush="{TemplateBinding BorderBrush}"
            Foreground="{TemplateBinding Foreground}" />
      </Border>
      <Popup PlacementTarget="{Binding ElementName=PART_ContentHost}" x:Name="PopCal">
         <Calendar x:Name="ActualCalendar"/>
      </Popup>
   </StackPanel>

   <ControlTemplate.Triggers>
      <EventTrigger RoutedEvent="ScrollViewer.MouseDoubleClick" SourceName="PART_ContentHost">
         <BeginStoryboard>
            <Storyboard>
               <BooleanAnimationUsingKeyFrames 
                  Storyboard.TargetName="PopCal" 
                  Storyboard.TargetProperty="(Popup.IsOpen)">
                  <DiscreteBooleanKeyFrame KeyTime="00:00:00" Value="True"/>
               </BooleanAnimationUsingKeyFrames>
            </Storyboard>
         </BeginStoryboard>
      </EventTrigger>

      <EventTrigger RoutedEvent="Calendar.SelectedDatesChanged" SourceName="ActualCalendar">
         <BeginStoryboard>
            <Storyboard>
               <BooleanAnimationUsingKeyFrames 
                  Storyboard.TargetName="PopCal" 
                  Storyboard.TargetProperty="(Popup.IsOpen)">
                  <DiscreteBooleanKeyFrame KeyTime="00:00:00" Value="False"/>
               </BooleanAnimationUsingKeyFrames>
            </Storyboard>


            WHAT WOULD I PUT HERE to have the selected date of the popup calendar
            inserted into the content of the PART_ContentHost...
            <Storyboard>
               <BooleanAnimationUsingKeyFrames 
                  Storyboard.TargetName="PART_ContentHost" 
                  Storyboard.TargetProperty="(Content)">
                  <DiscreteBooleanKeyFrame KeyTime="00:00:00" Value=" ????? "/>
               </BooleanAnimationUsingKeyFrames>
            </Storyboard>

         </BeginStoryboard>
      </EventTrigger>
   </ControlTemplate.Triggers>
</ControlTemplate>

<Style TargetType="{x:Type TextBox}" x:Key="STextBox" >
   <!--<Setter Property="OverridesDefaultStyle" Value="True"/>-->
   <Setter Property="FontFamily" Value="Arial" />
   <Setter Property="FontSize" Value="12" />
   <Setter Property="Height" Value="20" />
   <Setter Property="Width" Value="100" />
   <Setter Property="VerticalContentAlignment" Value="Bottom" />
   <Setter Property="HorizontalContentAlignment" Value="Left" />
   <Setter Property="HorizontalAlignment" Value="Left" />
   <!-- Padding is Left, Top, Right, Bottom -->
   <Setter Property="Padding" Value="2,0,0,2" />
   <Setter Property="Margin" Value="0,0,0,0" />

   <Setter Property="Visibility" Value="Visible" />
   <Setter Property="IsEnabled" Value="True" />

   <Setter Property="CharacterCasing" Value="Upper" />
   <Setter Property="BorderThickness" Value="1" />

   <Setter Property="BorderBrush" Value="Black" />
   <Setter Property="Background" Value="White" />
   <Setter Property="Foreground" Value="Black" />

   <Setter Property="Template" Value="{StaticResource CTTextBox}" />
</Style>

Answer 1

我确信问题可以通过多种方式解决，但在这些情况下，我通常会做出附加行为。但是情况不太正常，因为实现了控制的模板。在任何情况下，我认为附加行为适合这种情况，在你的位置我会这样做。

附加行为是非常强大且方便的解决方案，完全满足MVVM模式，也可以在Blend中使用（具有预定义的接口）。附加行为 - 是附加属性，它具有一个事件处理程序来更改此属性，并且所有逻辑都在此处理程序中实现。

在开始意识到这种行为之前，我会考虑对模板进行的一些更改。

我有点不明白你为什么使用PART_ContentHost ScrollViewer控件，也许会有几个日期，需要用滚动显示它们。在WPF中，显示内容需要两个控件：

ContentPresenter
ContentControl中

ContentControl

Popup

AllowsTransparency="True"
VerticalOffset="4"
HorizontalOffset="-5"

为了更好的可视化。现在转到行为的例子。

XAML

<Window.Resources>
    <ControlTemplate x:Key="CTTextBox" TargetType="{x:Type TextBox}">
        <StackPanel AttachedBehaviors:SelectDateBehavior.IsEnabled="True"> <!-- Here is determined behaviour -->
            <Border x:Name="targetBorder" 
                    Width="{TemplateBinding Width}"
                    Height="{TemplateBinding Height}"
                    BorderBrush="{TemplateBinding BorderBrush}"
                    BorderThickness="{TemplateBinding BorderThickness}"
                    Background="{TemplateBinding Background}"
                    TextBlock.Foreground="{TemplateBinding Foreground}"
                    SnapsToDevicePixels="True">

                <ContentControl x:Name="ContentHost"
                                Content="{TemplateBinding Text}"
                                HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                VerticalAlignment="{TemplateBinding VerticalContentAlignment}" 
                                Margin="4,0,0,0" />
            </Border>

            <Popup x:Name="PopCal" 
                   AllowsTransparency="True"
                   VerticalOffset="4"
                   HorizontalOffset="-5"
                   PlacementTarget="{Binding ElementName=ContentHost}">

                <Calendar x:Name="ActualCalendar" />
            </Popup>
        </StackPanel>
    </ControlTemplate>

    <Style TargetType="{x:Type TextBox}" x:Key="STextBox">
        <Setter Property="FontFamily" Value="Arial" />
        <Setter Property="FontSize" Value="12" />
        <Setter Property="Height" Value="25" />
        <Setter Property="Width" Value="100" />
        <Setter Property="VerticalContentAlignment" Value="Center" />
        <Setter Property="HorizontalContentAlignment" Value="Left" />
        <Setter Property="HorizontalAlignment" Value="Center" />       
        <Setter Property="CharacterCasing" Value="Upper" />
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="BorderBrush" Value="Gray" />
        <Setter Property="Background" Value="AliceBlue" />
        <Setter Property="Foreground" Value="Black" />
        <Setter Property="Template" Value="{StaticResource CTTextBox}" />
    </Style>
</Window.Resources>

<Grid>
    <TextBox Style="{StaticResource STextBox}"
             Text="Select date" />
</Grid>

Atatched Behavior

public class SelectDateBehavior
{
    #region IsEnabled Dependency Property

    public static readonly DependencyProperty IsEnabledProperty;

    public static void SetIsEnabled(DependencyObject DepObject, bool value)
    {
        DepObject.SetValue(IsEnabledProperty, value);
    }

    public static bool GetIsEnabled(DependencyObject DepObject)
    {
        return (bool)DepObject.GetValue(IsEnabledProperty);
    }

    static SelectDateBehavior()
    {
        IsEnabledProperty = DependencyProperty.RegisterAttached("IsEnabled",
                                                            typeof(bool),
                                                            typeof(SelectDateBehavior),
                                                            new UIPropertyMetadata(false, IsEnabledChanged));
    }

    #endregion

    #region IsEnabledChanged Handler

    private static void IsEnabledChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e) 
    {
        Panel panel = sender as Panel;

        if (panel != null)
        {
            if (e.NewValue is bool && ((bool)e.NewValue) == true)
            {
                panel.Loaded += new RoutedEventHandler(panelLoaded);
            }
            else
            {
                panel.Loaded -= new RoutedEventHandler(panelLoaded);
            }
        }
    }

    #endregion

    #region Panel Loaded Handler

    private static void panelLoaded(object sender, RoutedEventArgs e) 
    {
        Panel panel = sender as Panel;
        Border border = panel.FindName("targetBorder") as Border;
        ContentControl contentHost = border.FindName("ContentHost") as ContentControl;
        Popup popup = panel.FindName("PopCal") as Popup;

        if (popup != null)
        {
            Calendar calendar = popup.FindName("ActualCalendar") as Calendar;                
            calendar.SelectedDatesChanged += new EventHandler<SelectionChangedEventArgs>(calendarSelectedDatesChanged);
        }

        if (contentHost != null)
        {
            contentHost.MouseDoubleClick += new MouseButtonEventHandler(contentHostMouseDoubleClick);
        }          
    }

    #endregion

    #region ContentHost MouseDoubleClick Handler

    private static void contentHostMouseDoubleClick(object sender, MouseButtonEventArgs e) 
    {
        ContentControl contentHost = sender as ContentControl;
        Border border = contentHost.Parent as Border;
        Panel panel = border.Parent as Panel;
        Popup popup = panel.FindName("PopCal") as Popup;

        if (popup != null) 
        {
            popup.IsOpen = true;
        }
    }

    #endregion

    #region Calendar SelectedDatesChanged Handler

    private static void calendarSelectedDatesChanged(object sender, SelectionChangedEventArgs e) 
    {
        Calendar calendar = sender as Calendar;
        Popup popup = calendar.Parent as Popup;
        Panel panel = popup.Parent as Panel;
        Border border = panel.FindName("targetBorder") as Border;
        ContentControl contentHost = border.FindName("ContentHost") as ContentControl;

        if (popup != null) 
        {
            contentHost.Content = calendar.SelectedDate;
            popup.IsOpen = false;
        }
    }

    #endregion
}

Output

enter image description here

在此处设置当前日期：

private static void calendarSelectedDatesChanged(object sender, SelectionChangedEventArgs e) 
{
    // Skipped a few lines of code
    if (popup != null) 
    {
        contentHost.Content = calendar.SelectedDate;
        popup.IsOpen = false;
    }
}

<强> Some notes

让我提请注意一些功能。首先，我们必须摆脱EvenTrigger Storyboard，因为在具有最高优先级设置值的WPF动画中，这意味着如果我们在动画中设置值IsOpen，则从其他来源（代码等）访问。）不可能。所以我把所有的触发器/事件留在了侧面行为上。

其次，解决方案与模板和控件的结构密切相关。这意味着如果你必须改变模板的结构，你必须改变和行为（可能不多）。

此示例可用here。

控制模板故事板，在同一模板内的其他控件中设置值

1 个答案: