ChartDirector 7.1 (.NET Edition)

Track Line with Axis Labels (Windows)




NOTE: For conciseness, some of the following descriptions only mention WinChartViewer. Those descriptions apply to WPFChartViewer as well.

This sample program demonstrates a track cursor programmed with the following features:

The code first draws the chart. Then in the WinChartViewer.MouseMovePlotArea event handler, the track cursor is drawn to reflect the mouse position. The track cursor is configured to automatically hide itself when the mouse leaves the plot area.

The trackLineAxis method is the routine that draws the track cursor. Its key elements are:

Source Code Listing

[Windows Forms - C# version] NetWinCharts\CSharpWinCharts\frmtrackaxis.cs
using System; using System.Collections; using System.Windows.Forms; using ChartDirector; namespace CSharpChartExplorer { public partial class FrmTrackAxis : Form { public FrmTrackAxis() { InitializeComponent(); } private void FrmTrackAxis_Load(object sender, EventArgs e) { // Data for the chart as 2 random data series RanSeries r = new RanSeries(127); double[] data0 = r.getSeries(180, 10, -1.5, 1.5); double[] data1 = r.getSeries(180, 150, -15, 15); DateTime[] timeStamps = r.getDateSeries(180, new DateTime(2011, 1, 1), 86400); // Create a XYChart object of size 670 x 400 pixels XYChart c = new XYChart(670, 400); // Add a title to the chart using 18pt Times New Roman Bold Italic font c.addTitle("Plasma Stabilizer Energy Usage", "Times New Roman Bold Italic", 18); // Set the plotarea at (50, 55) with width 100 pixels less than chart width, and height 90 pixels // less than chart height. Use a vertical gradient from light blue (f0f6ff) to sky blue (a0c0ff) // as background. Set border to transparent and grid lines to white (ffffff). c.setPlotArea(50, 55, c.getWidth() - 100, c.getHeight() - 90, c.linearGradientColor(0, 55, 0, c.getHeight() - 35, 0xf0f6ff, 0xa0c0ff), -1, Chart.Transparent, 0xffffff, 0xffffff); // Add a legend box at (50, 25) using horizontal layout. Use 10pt Arial Bold as font. Set the // background and border color to Transparent. c.addLegend(50, 25, false, "Arial Bold", 10).setBackground(Chart.Transparent); // Set axis label style to 8pt Arial Bold c.xAxis().setLabelStyle("Arial Bold", 8); c.yAxis().setLabelStyle("Arial Bold", 8); c.yAxis2().setLabelStyle("Arial Bold", 8); // Set the axis stem to transparent c.xAxis().setColors(Chart.Transparent); c.yAxis().setColors(Chart.Transparent); c.yAxis2().setColors(Chart.Transparent); // Configure x-axis label format c.xAxis().setMultiFormat(Chart.StartOfYearFilter(), "{value|mm/yyyy} ", Chart.StartOfMonthFilter( ), "{value|mm}"); // Add axis title using 10pt Arial Bold Italic font c.yAxis().setTitle("Power Usage (Watt)", "Arial Bold Italic", 10); c.yAxis2().setTitle("Effective Load (kg)", "Arial Bold Italic", 10); // Add a line layer to the chart using a line width of 2 pixels. LineLayer layer = c.addLineLayer2(); layer.setLineWidth(2); // Add 2 data series to the line layer layer.setXData(timeStamps); layer.addDataSet(data0, 0xcc0000, "Power Usage"); layer.addDataSet(data1, 0x008800, "Effective Load").setUseYAxis2(); // Assign the chart to the WinChartViewer winChartViewer1.Chart = c; } // // Draw track cursor when mouse is moving over plotarea // private void winChartViewer1_MouseMovePlotArea(object sender, MouseEventArgs e) { WinChartViewer viewer = (WinChartViewer)sender; trackLineAxis((XYChart)viewer.Chart, viewer.PlotAreaMouseX); viewer.updateDisplay(); // Hide the track cursor when the mouse leaves the plot area viewer.removeDynamicLayer("MouseLeavePlotArea"); } // // Draw track line with axis labels // private void trackLineAxis(XYChart c, int mouseX) { // Clear the current dynamic layer and get the DrawArea object to draw on it. DrawArea d = c.initDynamicLayer(); // The plot area object PlotArea plotArea = c.getPlotArea(); // Get the data x-value that is nearest to the mouse, and find its pixel coordinate. double xValue = c.getNearestXValue(mouseX); int xCoor = c.getXCoor(xValue); // The vertical track line is drawn up to the highest data point (the point with smallest // y-coordinate). We need to iterate all datasets in all layers to determine where it is. int minY = plotArea.getBottomY(); // Iterate through all layers to find the highest data point for(int i = 0; i < c.getLayerCount(); ++i) { Layer layer = c.getLayerByZ(i); // The data array index of the x-value int xIndex = layer.getXIndexOf(xValue); // Iterate through all the data sets in the layer for(int j = 0; j < layer.getDataSetCount(); ++j) { ChartDirector.DataSet dataSet = layer.getDataSetByZ(j); double dataPoint = dataSet.getPosition(xIndex); if ((dataPoint != Chart.NoValue) && (dataSet.getDataColor() != Chart.Transparent)) { minY = Math.Min(minY, c.getYCoor(dataPoint, dataSet.getUseYAxis())); } } } // Draw a vertical track line at the x-position up to the highest data point. d.vline(Math.Max(minY, plotArea.getTopY()), plotArea.getBottomY() + 6, xCoor, d.dashLineColor( 0x000000, 0x0101)); // Draw a label on the x-axis to show the track line position d.text("<*font,bgColor=000000*> " + c.xAxis().getFormattedLabel(xValue, "mmm dd, yyyy") + " <*/font*>", "Arial Bold", 8).draw(xCoor, plotArea.getBottomY() + 6, 0xffffff, Chart.Top); // Iterate through all layers to build the legend array for(int i = 0; i < c.getLayerCount(); ++i) { Layer layer = c.getLayerByZ(i); // The data array index of the x-value int xIndex = layer.getXIndexOf(xValue); // Iterate through all the data sets in the layer for(int j = 0; j < layer.getDataSetCount(); ++j) { ChartDirector.DataSet dataSet = layer.getDataSetByZ(j); // The positional value, axis binding, pixel coordinate and color of the data point. double dataPoint = dataSet.getPosition(xIndex); Axis yAxis = dataSet.getUseYAxis(); int yCoor = c.getYCoor(dataPoint, yAxis); int color = dataSet.getDataColor(); // Draw the axis label only for visible data points of named data sets if ((dataPoint != Chart.NoValue) && (color != Chart.Transparent) && (yCoor >= plotArea.getTopY()) && (yCoor <= plotArea.getBottomY())) { // The axis label consists of 3 parts - a track dot for the data point, an axis label, // and a line joining the track dot to the axis label. // Draw the line first. The end point of the line at the axis label side depends on // whether the label is at the left or right side of the axis (that is, on whether the // axis is on the left or right side of the plot area). int xPos = yAxis.getX() + ((yAxis.getAlignment() == Chart.Left) ? -4 : 4); d.hline(xCoor, xPos, yCoor, d.dashLineColor(color, 0x0101)); // Draw the track dot d.circle(xCoor, yCoor, 4, 4, color, color); // Draw the axis label. If the axis is on the left side of the plot area, the labels // should right aligned to the axis, and vice versa. d.text("<*font,bgColor=" + color.ToString("x") + "*> " + c.formatValue(dataPoint, "{value|P4}") + " <*/font*>", "Arial Bold", 8).draw(xPos, yCoor, 0xffffff, (( yAxis.getAlignment() == Chart.Left) ? Chart.Right : Chart.Left)); } } } } } }

[Windows Forms - VB Version] NetWinCharts\VBNetWinCharts\frmtrackaxis.vb
Imports ChartDirector Imports System.Collections Public Class FrmTrackAxis Private Sub FrmTrackAxis_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load ' Data for the chart as 2 random data series Dim r As RanSeries = New RanSeries(127) Dim data0() As Double = r.getSeries(180, 10, -1.5, 1.5) Dim data1() As Double = r.getSeries(180, 150, -15, 15) Dim timeStamps() As Date = r.getDateSeries(180, DateSerial(2011, 1, 1), 86400) ' Create a XYChart object of size 670 x 400 pixels Dim c As XYChart = New XYChart(670, 400) ' Add a title to the chart using 18pt Times New Roman Bold Italic font c.addTitle("Plasma Stabilizer Energy Usage", "Times New Roman Bold Italic", 18) ' Set the plotarea at (50, 55) with width 100 pixels less than chart width, and height 90 pixels less ' than chart height. Use a vertical gradient from light blue (f0f6ff) to sky blue (a0c0ff) as ' background. Set border to transparent and grid lines to white (ffffff). c.setPlotArea(50, 55, c.getWidth() - 100, c.getHeight() - 90, c.linearGradientColor(0, 55, 0, _ c.getHeight() - 35, &Hf0f6ff, &Ha0c0ff), -1, Chart.Transparent, &Hffffff, &Hffffff) ' Add a legend box at (50, 25) using horizontal layout. Use 10pt Arial Bold as font. Set the ' background and border color to Transparent. c.addLegend(50, 25, False, "Arial Bold", 10).setBackground(Chart.Transparent) ' Set axis label style to 8pt Arial Bold c.xAxis().setLabelStyle("Arial Bold", 8) c.yAxis().setLabelStyle("Arial Bold", 8) c.yAxis2().setLabelStyle("Arial Bold", 8) ' Set the axis stem to transparent c.xAxis().setColors(Chart.Transparent) c.yAxis().setColors(Chart.Transparent) c.yAxis2().setColors(Chart.Transparent) ' Configure x-axis label format c.xAxis().setMultiFormat(Chart.StartOfYearFilter(), "{value|mm/yyyy} ", Chart.StartOfMonthFilter(), _ "{value|mm}") ' Add axis title using 10pt Arial Bold Italic font c.yAxis().setTitle("Power Usage (Watt)", "Arial Bold Italic", 10) c.yAxis2().setTitle("Effective Load (kg)", "Arial Bold Italic", 10) ' Add a line layer to the chart using a line width of 2 pixels. Dim layer As LineLayer = c.addLineLayer2() layer.setLineWidth(2) ' Add 2 data series to the line layer layer.setXData(timeStamps) layer.addDataSet(data0, &Hcc0000, "Power Usage") layer.addDataSet(data1, &H008800, "Effective Load").setUseYAxis2() ' Assign the chart to the WinChartViewer winChartViewer1.Chart = c End Sub ' ' Draw track cursor when mouse is moving over plotarea ' Private Sub winChartViewer1_MouseMovePlotArea(ByVal sender As Object, _ ByVal e As System.Windows.Forms.MouseEventArgs) Handles winChartViewer1.MouseMovePlotArea Dim viewer As WinChartViewer = sender trackLineAxis(viewer.Chart, viewer.PlotAreaMouseX) viewer.updateDisplay() ' Hide the track cursor when the mouse leaves the plot area viewer.removeDynamicLayer("MouseLeavePlotArea") End Sub ' ' Draw track line with axis labels ' Private Sub trackLineAxis(c As XYChart, mouseX As Integer) ' Clear the current dynamic layer and get the DrawArea object to draw on it. Dim d As DrawArea = c.initDynamicLayer() ' The plot area object Dim plotArea As PlotArea = c.getPlotArea() ' Get the data x-value that is nearest to the mouse, and find its pixel coordinate. Dim xValue As Double = c.getNearestXValue(mouseX) Dim xCoor As Integer = c.getXCoor(xValue) ' The vertical track line is drawn up to the highest data point (the point with smallest ' y-coordinate). We need to iterate all datasets in all layers to determine where it is. Dim minY As Integer = plotArea.getBottomY() ' Iterate through all layers to find the highest data point For i As Integer = 0 To c.getLayerCount() - 1 Dim layer As Layer = c.getLayerByZ(i) ' The data array index of the x-value Dim xIndex As Integer = layer.getXIndexOf(xValue) ' Iterate through all the data sets in the layer For j As Integer = 0 To layer.getDataSetCount() - 1 Dim dataSet As ChartDirector.DataSet = layer.getDataSetByZ(j) Dim dataPoint As Double = dataSet.getPosition(xIndex) If (dataPoint <> Chart.NoValue) AndAlso (dataSet.getDataColor() <> Chart.Transparent) Then minY = Math.Min(minY, c.getYCoor(dataPoint, dataSet.getUseYAxis())) End If Next Next ' Draw a vertical track line at the x-position up to the highest data point. d.vline(Math.Max(minY, plotArea.getTopY()), plotArea.getBottomY() + 6, xCoor, d.dashLineColor( _ &H000000, &H0101)) ' Draw a label on the x-axis to show the track line position d.text("<*font,bgColor=000000*> " & c.xAxis().getFormattedLabel(xValue, "mmm dd, yyyy") & _ " <*/font*>", "Arial Bold", 8).draw(xCoor, plotArea.getBottomY() + 6, &Hffffff, Chart.Top) ' Iterate through all layers to build the legend array For i As Integer = 0 To c.getLayerCount() - 1 Dim layer As Layer = c.getLayerByZ(i) ' The data array index of the x-value Dim xIndex As Integer = layer.getXIndexOf(xValue) ' Iterate through all the data sets in the layer For j As Integer = 0 To layer.getDataSetCount() - 1 Dim dataSet As ChartDirector.DataSet = layer.getDataSetByZ(j) ' The positional value, axis binding, pixel coordinate and color of the data point. Dim dataPoint As Double = dataSet.getPosition(xIndex) Dim yAxis As Axis = dataSet.getUseYAxis() Dim yCoor As Integer = c.getYCoor(dataPoint, yAxis) Dim color As Integer = dataSet.getDataColor() ' Draw the axis label only for visible data points of named data sets If (dataPoint <> Chart.NoValue) AndAlso (color <> Chart.Transparent) AndAlso (yCoor >= _ plotArea.getTopY()) AndAlso (yCoor <= plotArea.getBottomY()) Then ' The axis label consists of 3 parts - a track dot for the data point, an axis label, and ' a line joining the track dot to the axis label. ' Draw the line first. The end point of the line at the axis label side depends on whether ' the label is at the left or right side of the axis (that is, on whether the axis is on ' the left or right side of the plot area). Dim xPos As Integer = yAxis.getX() + IIf(yAxis.getAlignment() = Chart.Left, -4, 4) d.hline(xCoor, xPos, yCoor, d.dashLineColor(color, &H0101)) ' Draw the track dot d.circle(xCoor, yCoor, 4, 4, color, color) ' Draw the axis label. If the axis is on the left side of the plot area, the labels should ' right aligned to the axis, and vice versa. d.text("<*font,bgColor=" & Hex(color) & "*> " & c.formatValue(dataPoint, "{value|P4}") & _ " <*/font*>", "Arial Bold", 8).draw(xPos, yCoor, &Hffffff, IIf(yAxis.getAlignment() _ = Chart.Left, Chart.Right, Chart.Left)) End If Next Next End Sub End Class

[WPF - XAML] NetWPFCharts\CSharpWPFCharts\TrackAxisWindow.xaml
<Window x:Class="CSharpWPFCharts.TrackAxisWindow" 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" xmlns:local="clr-namespace:CSharpWPFCharts" mc:Ignorable="d" xmlns:ChartDirector="clr-namespace:ChartDirector;assembly=netchartdir" UseLayoutRounding="True" Title="Track Line with Axis Labels" SizeToContent="WidthAndHeight" ResizeMode="NoResize" Loaded="Window_Loaded"> <Grid> <ChartDirector:WPFChartViewer x:Name="WPFChartViewer1" Margin="5" MouseMovePlotArea="WPFChartViewer1_MouseMovePlotArea" /> </Grid> </Window>

[WPF - C#] NetWPFCharts\CSharpWPFCharts\TrackAxisWindow.xaml.cs
using System; using System.Collections; using System.Windows; using System.Windows.Input; using ChartDirector; namespace CSharpWPFCharts { public partial class TrackAxisWindow : Window { public TrackAxisWindow() { InitializeComponent(); } private void Window_Loaded(object sender, RoutedEventArgs e) { // Data for the chart as 2 random data series RanSeries r = new RanSeries(127); double[] data0 = r.getSeries(180, 10, -1.5, 1.5); double[] data1 = r.getSeries(180, 150, -15, 15); DateTime[] timeStamps = r.getDateSeries(180, new DateTime(2011, 1, 1), 86400); // Create a XYChart object of size 670 x 400 pixels XYChart c = new XYChart(670, 400); // Add a title to the chart using 18pt Times New Roman Bold Italic font c.addTitle("Plasma Stabilizer Energy Usage", "Times New Roman Bold Italic", 18); // Set the plotarea at (50, 55) with width 100 pixels less than chart width, and height 90 pixels // less than chart height. Use a vertical gradient from light blue (f0f6ff) to sky blue (a0c0ff) // as background. Set border to transparent and grid lines to white (ffffff). c.setPlotArea(50, 55, c.getWidth() - 100, c.getHeight() - 90, c.linearGradientColor(0, 55, 0, c.getHeight() - 35, 0xf0f6ff, 0xa0c0ff), -1, Chart.Transparent, 0xffffff, 0xffffff); // Add a legend box at (50, 25) using horizontal layout. Use 10pt Arial Bold as font. Set the // background and border color to Transparent. c.addLegend(50, 25, false, "Arial Bold", 10).setBackground(Chart.Transparent); // Set axis label style to 8pt Arial Bold c.xAxis().setLabelStyle("Arial Bold", 8); c.yAxis().setLabelStyle("Arial Bold", 8); c.yAxis2().setLabelStyle("Arial Bold", 8); // Set the axis stem to transparent c.xAxis().setColors(Chart.Transparent); c.yAxis().setColors(Chart.Transparent); c.yAxis2().setColors(Chart.Transparent); // Configure x-axis label format c.xAxis().setMultiFormat(Chart.StartOfYearFilter(), "{value|mm/yyyy} ", Chart.StartOfMonthFilter( ), "{value|mm}"); // Add axis title using 10pt Arial Bold Italic font c.yAxis().setTitle("Power Usage (Watt)", "Arial Bold Italic", 10); c.yAxis2().setTitle("Effective Load (kg)", "Arial Bold Italic", 10); // Add a line layer to the chart using a line width of 2 pixels. LineLayer layer = c.addLineLayer2(); layer.setLineWidth(2); // Add 2 data series to the line layer layer.setXData(timeStamps); layer.addDataSet(data0, 0xcc0000, "Power Usage"); layer.addDataSet(data1, 0x008800, "Effective Load").setUseYAxis2(); // Assign the chart to the WPFChartViewer WPFChartViewer1.Chart = c; } // // Draw track cursor when mouse is moving over plotarea // private void WPFChartViewer1_MouseMovePlotArea(object sender, MouseEventArgs e) { WPFChartViewer viewer = (WPFChartViewer)sender; trackLineAxis((XYChart)viewer.Chart, viewer.PlotAreaMouseX); viewer.updateDisplay(); // Hide the track cursor when the mouse leaves the plot area viewer.removeDynamicLayer("MouseLeavePlotArea"); } // // Draw track line with axis labels // private void trackLineAxis(XYChart c, int mouseX) { // Clear the current dynamic layer and get the DrawArea object to draw on it. DrawArea d = c.initDynamicLayer(); // The plot area object PlotArea plotArea = c.getPlotArea(); // Get the data x-value that is nearest to the mouse, and find its pixel coordinate. double xValue = c.getNearestXValue(mouseX); int xCoor = c.getXCoor(xValue); // The vertical track line is drawn up to the highest data point (the point with smallest // y-coordinate). We need to iterate all datasets in all layers to determine where it is. int minY = plotArea.getBottomY(); // Iterate through all layers to find the highest data point for(int i = 0; i < c.getLayerCount(); ++i) { Layer layer = c.getLayerByZ(i); // The data array index of the x-value int xIndex = layer.getXIndexOf(xValue); // Iterate through all the data sets in the layer for(int j = 0; j < layer.getDataSetCount(); ++j) { ChartDirector.DataSet dataSet = layer.getDataSetByZ(j); double dataPoint = dataSet.getPosition(xIndex); if ((dataPoint != Chart.NoValue) && (dataSet.getDataColor() != Chart.Transparent)) { minY = Math.Min(minY, c.getYCoor(dataPoint, dataSet.getUseYAxis())); } } } // Draw a vertical track line at the x-position up to the highest data point. d.vline(Math.Max(minY, plotArea.getTopY()), plotArea.getBottomY() + 6, xCoor, d.dashLineColor( 0x000000, 0x0101)); // Draw a label on the x-axis to show the track line position d.text("<*font,bgColor=000000*> " + c.xAxis().getFormattedLabel(xValue, "mmm dd, yyyy") + " <*/font*>", "Arial Bold", 8).draw(xCoor, plotArea.getBottomY() + 6, 0xffffff, Chart.Top); // Iterate through all layers to build the legend array for(int i = 0; i < c.getLayerCount(); ++i) { Layer layer = c.getLayerByZ(i); // The data array index of the x-value int xIndex = layer.getXIndexOf(xValue); // Iterate through all the data sets in the layer for(int j = 0; j < layer.getDataSetCount(); ++j) { ChartDirector.DataSet dataSet = layer.getDataSetByZ(j); // The positional value, axis binding, pixel coordinate and color of the data point. double dataPoint = dataSet.getPosition(xIndex); Axis yAxis = dataSet.getUseYAxis(); int yCoor = c.getYCoor(dataPoint, yAxis); int color = dataSet.getDataColor(); // Draw the axis label only for visible data points of named data sets if ((dataPoint != Chart.NoValue) && (color != Chart.Transparent) && (yCoor >= plotArea.getTopY()) && (yCoor <= plotArea.getBottomY())) { // The axis label consists of 3 parts - a track dot for the data point, an axis label, // and a line joining the track dot to the axis label. // Draw the line first. The end point of the line at the axis label side depends on // whether the label is at the left or right side of the axis (that is, on whether the // axis is on the left or right side of the plot area). int xPos = yAxis.getX() + ((yAxis.getAlignment() == Chart.Left) ? -4 : 4); d.hline(xCoor, xPos, yCoor, d.dashLineColor(color, 0x0101)); // Draw the track dot d.circle(xCoor, yCoor, 4, 4, color, color); // Draw the axis label. If the axis is on the left side of the plot area, the labels // should right aligned to the axis, and vice versa. d.text("<*font,bgColor=" + color.ToString("x") + "*> " + c.formatValue(dataPoint, "{value|P4}") + " <*/font*>", "Arial Bold", 8).draw(xPos, yCoor, 0xffffff, (( yAxis.getAlignment() == Chart.Left) ? Chart.Right : Chart.Left)); } } } } } }