About chart

Hi.I have a question to ask.It's like this:

<Window x:Class="Test.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:Test.Classes"
    Title="MainWindow" Height="350" Width="525" xmlns:ms="http://namespaces.mindscape.co.nz/wpf" Loaded="Window_Loaded">
<Grid>
    <ms:Chart  Margin="0,0,50,0"  Name="LinesControl"  LegendPosition="None"  AllowDrop="True">
        <ms:Chart.ForegroundElements >
            <local:TrackingElement  ValueDisplayTemplate="{StaticResource ValueDisplayTemplate}" LineStyle="{StaticResource LineStyle}" Visibility="Visible" />
        </ms:Chart.ForegroundElements>
        <ms:Chart.XAxis>
            <ms:ChartAxis  Name="LinesAxis" Title="时间" Minimum="0" Maximum="1000" Visibility="Visible" />
        </ms:Chart.XAxis>
        <ms:Chart.YAxis>
            <ms:ChartAxis Title="值"  Minimum="0" Maximum="1000" Visibility="Hidden" />
        </ms:Chart.YAxis>
    </ms:Chart>
    <Button Content="Button" Height="23" HorizontalAlignment="Left" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" />
</Grid>

public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        List<object> PointList1 = new List<object>();
        for (int i = 0; i < 2000; i++)
        {
            Point _Point = new Point(i, i);
            PointList1.Add(_Point);
        }

        ChartAxis _ChartAxis1 = new ChartAxis();
        _ChartAxis1.Title = "1";

        LineSeries _LineSeries1 = new LineSeries();
        LinesControl.Series.Add(_LineSeries1);
        _LineSeries1.YAxisTitle = "1";
        LinesControl.Series[0].ItemsSource = PointList1;
    }

    private void button1_Click(object sender, RoutedEventArgs e)
    {
        List<object> PointList3 = new List<object>();
        for (int i = 0; i < 2000; i++)
        {
            Point _Point = new Point(i, i + 90);
            PointList3.Add(_Point);
        }
        ChartAxis _ChartAxis3 = new ChartAxis();
        _ChartAxis3.Title = "3";
        LinesControl.AlternativeYAxes.Add(_ChartAxis3);

        LineSeries _LineSeries3 = new LineSeries();
        _LineSeries3.YAxisTitle = "3";
        LinesControl.Series.Add(_LineSeries3);

        LinesControl.Series[LinesControl.Series.Count-1].ItemsSource = PointList3;
    }
}

1. I use the TrackingElement classes in your example project and want to show data of lines. When window is loaded,the data of first line can show correctly.But when I click button1 to add a line to chart, the data of line added can't show.How to solve it? I hope when I add some lines,the datas of these lines can show .

Hello

Thanks for the feedback and the code examples. To resolve this, You can start by attaching a collection changed event handler to the Chart.Series collection in the TrackingElement_Loaded method like this:

_chart.Series.CollectionChanged += new NotifyCollectionChangedEventHandler(Series_CollectionChanged);

Then in this collection changed event handler, simply reset the _lineSeries cache like this:

private void Series_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
  _lineSeries = new List<LineAreaSeriesBase>();
  foreach (DataSeries series in _chart.Series)
  {
    if (series is LineAreaSeriesBase)
    {
      _lineSeries.Add(series as LineAreaSeriesBase);
    }
  }
}

After I did this, I noticed another issue related to having alternate axis. To resolve this other issue, I went to the UpdateElements method and replaced this line:

_sortedSeries.Add(y, series);

With this code:

_sortedSeries.Add(series.YAxis.ActualHeight - physicalPoint.Y, series);

And of course moved this code down a few lines so that it can use the physicalPoint variable.

I have updated this code in the TrackingElement class provided by the SampleExplorer. So if you're not sure about doing this yourself, you can download it through the next nightly builds.

Jason Fauchelle