Line Chart

Line chart is used to show trends and performance over a period of time. Line graphs are probably the most widely used graph for showing trend. This is useful in showing a spike in the traffic, prices, etc.

The chart from the image above is created with the following code:

<shield:ShieldChart ID="ShieldChart1" Width="580px" Height="400px" runat="server" 
    OnTakeDataSource="ShieldChart1_TakeDataSource"
    CssClass="chart">
    <PrimaryHeader Text="Electricity prices"></PrimaryHeader>
    <ExportOptions AllowExportToImage="false" AllowPrint="false" />
    <Axes>
        <shield:ChartAxisX 
            CategoricalValues="2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012"></shield:ChartAxisX>
        <shield:ChartAxisY>
            <Title Text="Price (EUR per kWh)"></Title>
        </shield:ChartAxisY>
    </Axes>
    <DataSeries>
        <shield:ChartLineSeries DataFieldY="Households" CollectionAlias="Households">
            <Settings EnablePointSelection="true">
                <PointMark>
                    <ActiveSettings>
                        <PointSelectedState DrawWidth="4" DrawRadius="4" />
                    </ActiveSettings>
                </PointMark>
            </Settings>
        </shield:ChartLineSeries>
        <shield:ChartLineSeries DataFieldY="Industry" CollectionAlias="Industry">
            <Settings EnablePointSelection="true">
                <PointMark>
                    <ActiveSettings>
                        <PointSelectedState DrawWidth="4" DrawRadius="4" />
                    </ActiveSettings>
                </PointMark>
            </Settings>
        </shield:ChartLineSeries>
    </DataSeries>
</shield:ShieldChart>

protected void ShieldChart1_TakeDataSource(object sender, Shield.Web.UI.ChartTakeDataSourceEventArgs e)
{
    List datasource = new List() 
    { 
        new Prices() { Households = 0.164, Industry= 0.103 },
        new Prices() { Households = 0.173, Industry= 0.105 },
        new Prices() { Households = 0.184, Industry= 0.112 },
        new Prices() { Households = 0.167, Industry= 0.111 },
        new Prices() { Households = 0.177, Industry= 0.102 },
        new Prices() { Households = 0.189, Industry= 0.099 },
        new Prices() { Households = 0.180, Industry= 0.110 },
        new Prices() { Households = 0.183, Industry= 0.113 },
        new Prices() { Households = 0.188, Industry= 0.117 },
        new Prices() { Households = 0.160, Industry= 0.119 },
        new Prices() { Households = 0.176, Industry= 0.123 },
        new Prices() { Households = 0.178, Industry= 0.117 }
    };

    ShieldChart1.DataSource = datasource;
}

private class Prices
{
    public double Households { get; set; }
    public double Industry { get; set; }
}

• When the chart is bound to collection of objects the X values are got by the field which name is set into the DataFieldX property of the ChartLineSeries. The Y values are got by the field which name is set into the DataFieldY property.
• The name that is shown in the legend is chosen via the CollectionAlias property of the ChartLineSeries.
• By default all X values are sorted in order line chart to be shown appropriately, however this behavior is controlled by the EnableValueXSorting property of the ChartLineSeries.
• The type of the ChartLineSeries can be changed by the Settings.SeriesDashStyle property and it can be set as: Solid, ShortDash, ShortDot, ShortDashDot,Dot, etc.
• DataStart and DataStep properties control the start value of the x axis and explicit value for the interval between a data series member values.
• All points from the ChartLineSeries are represented with ChartSeriesItem which belongs to the ChartLineSeries.Items collection.
  • The ChartLineSeries.Items can be added declarative without data binding.
  • The data binding and declarative approach can be mixed. However in order declarative items to be appended to the items created from the datasource the ShieldChart.AppendDataBoundItems property need to be set to "true".
• All setting related to ChartLineSeries are contained into the ChartLineSeries.Settings object.
  • The series color can be set via Color property.
  • If the AddToLegend is set to false the series is not added into the legend.
  • The animation of the series can be controlled by ChartLineSeries.Settings.EnableAnimation and ChartLineSeries.Settings.AnimationDuration properties.
  • If some values are missing (i.e. they are null/Nothing) from the series data you can have the chart work around this by setting the DrawNullValues property.
  • If the chart has more than one line series they can be ordered by the index set in ChartLineSeries.OrderIndex property.
  • Each point from the series can be selected if the EnablePointSelection property is set to true.
  • All selected points can be customized by Settings.PointMark.ActiveSettings.PointSelectedState object properties.
  • From the Settings.PointMark.ActiveSettings.PointHoveredState object properties you can change the appearance of each line when the user hovers it.
  • Each series has related tooltip which can be customized via the Settings.Tooltip object.
  • Each point from the series can have related text, which appearance is controlled by Settings.DataPointText property. You can changeBackgroundColor, BorderColor, Color, Padding, and TextAngle of the corresponding data point text.