c# - 使用 WPF 图表获取自定义工具提示？

Question

我使用以下方法创建了一个 ScatterSeries 图表:

    public ScatterPlot()
    {
        InitializeComponent();


        ScatterSeries a = new ScatterSeries();
        a.Title = "Series A";

        a.IndependentValuePath = "Key";
        a.DependentValuePath = "Value";

        scatterplot.Series.Add(a);

        ((ScatterSeries)scatterplot.Series[0]).ItemsSource = new KeyValuePair<DateTime, int>[]
         {
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(1), 0),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(2), 150),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(3), 150),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(4), 0),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(5), 0),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(8), 130),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(9), 130),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(10), 0),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(11), 0),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(15), 225),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(16), 225),
           new KeyValuePair<DateTime, int>(DateTime.Now.AddMonths(17), 0)
         };

    }

我有一本字典，其中每个数据点都映射到一个单独的文本标签。我想知道是否可以建立一个绑定(bind)，以便当我将鼠标移到一个点上时，我得到文本标签而不是实际数字？有关如何执行此操作的任何建议？

Answer 1

设置DataPoint样式...

    <charting:ScatterSeries DependentValuePath="Value"
                            IndependentValuePath="Key">
       <charting:DataPointSeries.DataPointStyle>
         <Style TargetType="{x:Type charting:DataPoint}">
              <EventSetter Event="MouseEnter" Handler="DataPoint_MouseEnter" />
              <!--Style.Triggers>
                 <Trigger Property="IsMouseDirectlyOver" Value="True">
                     <Setter Property="ToolTip" Value="Hi There!"/>
                 </Trigger>
             </Style.Triggers--> <!-- This doesnt work!-->
         </Style>
       </charting:DataPointSeries.DataPointStyle>
       <charting:DataPointSeries.ItemsSource>
            <Binding BindsDirectlyToSource="True"/>
       </charting:DataPointSeries.ItemsSource>
    </charting:ScatterSeries>

但是当我测试时，基于触发器的工具提示 setter 没有工作。事件 setter 虽然有效。因此，最快的解决方法可能是使用该事件 setter 并从处理程序中的代码后面设置 TooltipService.ToolTip。

但如果您使用的是 MVVM，那么您可以使用一些附加行为来处理此事件并显式设置工具提示。

或

您可以使用上述样式覆盖 ScatterDataPoint 模板，并将模板设置为此 NewTemplate ...

请注意，在下面的 ControlTemplate 中，我已将 ToolTipService.ToolTip 设置为 DataPoint 的工具提示。所以你将不得不使用上面的样式来设置 Template 和 ToolTip ...

 <!--  charting:ScatterDataPoint  -->

 <Style x:Key="NewTemplate" TargetType="charting:ScatterDataPoint">
    <Setter Property="Background" Value="Orange" />
    <Setter Property="IsTabStop" Value="False" />
    <Setter Property="BorderBrush" Value="#FF686868" />
    <Setter Property="Width" Value="8" />
    <Setter Property="Height" Value="8" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="charting:ScatterDataPoint">
                <Grid x:Name="Root" Opacity="0">
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualStateGroup.Transitions>
                                <VisualTransition GeneratedDuration="0:0:0.1" />
                            </VisualStateGroup.Transitions>
                            <VisualState x:Name="Normal" />
                            <VisualState x:Name="MouseOver">
                                <Storyboard>
                                    <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="MouseOverHighlight" Storyboard.TargetProperty="(UIElement.Opacity)">
                                        <SplineDoubleKeyFrame KeyTime="00:00:00" Value="0.3" />
                                    </DoubleAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="SelectionStates">
                            <VisualStateGroup.Transitions>
                                <VisualTransition GeneratedDuration="0:0:0.1" />
                            </VisualStateGroup.Transitions>
                            <VisualState x:Name="Unselected" />
                            <VisualState x:Name="Selected">
                                <Storyboard>
                                    <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="SelectionHighlight" Storyboard.TargetProperty="(UIElement.Opacity)">
                                        <SplineDoubleKeyFrame KeyTime="00:00:00" Value="0.185" />
                                    </DoubleAnimationUsingKeyFrames>
                                    <ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="SelectionHighlight" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
                                        <SplineColorKeyFrame KeyTime="00:00:00" Value="#FF8A8A8A" />
                                    </ColorAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="RevealStates">
                            <VisualStateGroup.Transitions>
                                <VisualTransition GeneratedDuration="0:0:0.5" />
                            </VisualStateGroup.Transitions>
                            <VisualState x:Name="Shown">
                                <Storyboard>
                                    <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="Root" Storyboard.TargetProperty="(UIElement.Opacity)">
                                        <SplineDoubleKeyFrame KeyTime="00:00:00" Value="1" />
                                    </DoubleAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Hidden">
                                <Storyboard>
                                    <DoubleAnimation Duration="0" Storyboard.TargetName="Root" Storyboard.TargetProperty="Opacity" To="0" />
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <ToolTipService.ToolTip>
                        <ContentControl Content="{TemplateBinding ToolTip}" />
                    </ToolTipService.ToolTip>
                        <Path Fill="{TemplateBinding Background}" Stroke="{TemplateBinding BorderBrush}" Stretch="Fill" StrokeThickness="1" StrokeLineJoin="Round" Data="F1 M 0,50L 50,0 100,50 50,100L 0,50 Z " />
                        <Path x:Name="MouseOverHighlight" Stretch="Fill" StrokeThickness="1" StrokeLineJoin="Round" Stroke="{x:Null}" Data="F1 M 0,50L 50,0 100,50 50,100L 0,50 Z  " Opacity="0" Fill="#FFFFFFFF" />
                        <Path x:Name="SelectionHighlight" Stretch="Fill" StrokeThickness="1" StrokeLineJoin="Round" Stroke="{x:Null}" Data="F1 M 0,50L 50,0 100,50 50,100L 0,50 Z " Fill="#FF959595" Opacity="0" />
                    </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
   </Style>