Applies to: Nevron Chart for .NET
How to store custom data in chart data points?
To store custom information for data point in Nevron Chart, you can use the Tags data series. You can work with Tags data series the same way as with the FillStyles or BorderStyles data series, but you can store any type of object. For example, the following code stores a custom object of type MyCustomData for the data point at index 5:
series.Tags[5] = new MyCustomData("some string", 42);
You can also work with the tags through the data point interface.
The following code example demonstrates how to use the Tags data series:
[C#]
using System;
using System.Windows.Forms;
using Nevron.Chart;
...
private void Form1_Load(object sender, EventArgs e)
{
NBarSeries bar = new NBarSeries();
bar.Values.AddRange(new double[] { 10, 20, 30, 17, 23 });
bar.Tags[0] = "str 0";
bar.Tags[1] = "str 1";
bar.Tags[2] = "str 2";
bar.Tags[3] = "str 3";
bar.Tags[4] = "str 4";
NChart chart = nChartControl1.Charts[0];
chart.Series.Add(bar);
nChartControl1.MouseDown += new MouseEventHandler(nChartControl1_MouseDown_Variant2);
}
void nChartControl1_MouseDown_Variant1(object sender, MouseEventArgs e)
{
NHitTestResult htr = nChartControl1.HitTest(e.Location);
if (htr.ChartElement == ChartElement.DataPoint)
{
NSeries series = htr.Series as NSeries;
if (series != null)
{
object obj = series.Tags[htr.DataPointIndex];
if (obj != null)
{
MessageBox.Show(obj.ToString());
}
}
}
}
void nChartControl1_MouseDown_Variant2(object sender, MouseEventArgs e)
{
NHitTestResult htr = nChartControl1.HitTest(e.Location);
if (htr.ChartElement == ChartElement.DataPoint)
{
NDataPoint dp = htr.Object as NDataPoint;
if (dp != null)
{
object obj = dp[DataPointValue.Tag];
if (obj != null)
{
MessageBox.Show(obj.ToString());
}
}
}
}
[VB.NET]
Imports Microsoft.VisualBasic
Imports System
Imports System.Windows.Forms
Imports Nevron.Chart
...
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
Dim bar As NBarSeries = New NBarSeries()
bar.Values.AddRange(New Double() { 10, 20, 30, 17, 23 })
bar.Tags(0) = "str 0"
bar.Tags(1) = "str 1"
bar.Tags(2) = "str 2"
bar.Tags(3) = "str 3"
bar.Tags(4) = "str 4"
Dim chart As NChart = nChartControl1.Charts(0)
chart.Series.Add(bar)
AddHandler nChartControl1.MouseDown, AddressOf nChartControl1_MouseDown_Variant2
End Sub
Private Sub nChartControl1_MouseDown_Variant1(ByVal sender As Object, ByVal e As MouseEventArgs)
Dim htr As NHitTestResult = nChartControl1.HitTest(e.Location)
If htr.ChartElement = ChartElement.DataPoint Then
Dim series As NSeries = TryCast(htr.Series, NSeries)
If Not series Is Nothing Then
Dim obj As Object = series.Tags(htr.DataPointIndex)
If Not obj Is Nothing Then
MessageBox.Show(obj.ToString())
End If
End If
End If
End Sub
Private Sub nChartControl1_MouseDown_Variant2(ByVal sender As Object, ByVal e As MouseEventArgs)
Dim htr As NHitTestResult = nChartControl1.HitTest(e.Location)
If htr.ChartElement = ChartElement.DataPoint Then
Dim dp As NDataPoint = TryCast(htr.Object, NDataPoint)
If Not dp Is Nothing Then
Dim obj As Object = dp(DataPointValue.Tag)
If Not obj Is Nothing Then
MessageBox.Show(obj.ToString())
End If
End If
End If
End Sub
Article ID: 181, Created On: 3/7/2011, Modified: 3/7/2011