SizeLegend Class

Represents a map legend that details the meaning of Bubble sizes in a Bubble chart.

Namespace: DevExpress.XtraMap

Assembly: DevExpress.XtraMap.v20.1.dll

Declaration

public class SizeLegend :
    ItemsLayerLegend,
    ISizeLegend,
    ILegend
Public Class SizeLegend
    Inherits ItemsLayerLegend
    Implements ISizeLegend,
               ILegend

Remarks

The following image shows an instance of the SizeLegend class.

SizeLegendExample

To show this legend on a map, create an instance of the SizeLegend class and add it to the MapControl.Legends collection. Then, assign the required Vector Items layer to the ItemsLayerLegend.Layer property of the legend. Note that this assigned layer should contain bubble charts, so that a legend can obtain the required information .

For more information, refer to Legends.

Examples

This example demonstrates how to generate bubble charts for a map control. Do the following:

    // Specify data for the bubble layer.
    BubbleLayer.Data = CreateData();
private IMapDataAdapter CreateData() {
    BubbleChartDataAdapter adapter = new BubbleChartDataAdapter() {
        DataSource = LoadData(),
        MeasureRules = CreateMeasureRules(),
        ItemMaxSize = 60,
        ItemMinSize = 10
    };

    #region #Mappings
    // Map the properties of chart items to the appropriate fields in the data source.
    adapter.Mappings.Latitude = "glat";
    adapter.Mappings.Longitude = "glon";
    adapter.Mappings.Value = "mag";
    #endregion #Mappings

    // Create attribute mappings to provide additional information about map items to the map.
    adapter.AttributeMappings.Add(new MapItemAttributeMapping("Magnitude", "mag"));
    adapter.AttributeMappings.Add(new MapItemAttributeMapping("Year", "yr"));
    adapter.AttributeMappings.Add(new MapItemAttributeMapping("Month", "mon"));
    adapter.AttributeMappings.Add(new MapItemAttributeMapping("Day", "day"));
    adapter.AttributeMappings.Add(new MapItemAttributeMapping("Depth", "dep"));

    return adapter;
}

private DataTable LoadData() {
    DataSet ds = new DataSet();
    ds.ReadXml(dataPath);
    DataTable dt = ds.Tables[0];
    dt.DefaultView.RowFilter = string.Format(CultureInfo.InvariantCulture, "(mag >= {0}) AND (mag <= {1})", minMagnitude, maxMagnitude);

    return ds.Tables[0];
}

private MeasureRules CreateMeasureRules() {
    MeasureRules measureRules = new MeasureRules();

    measureRules.ApproximateValues = true;
    measureRules.RangeDistribution = new LinearRangeDistribution();

    for (int i = minMagnitude; i < maxMagnitude; i++) {
        measureRules.RangeStops.Add(i);
    }

    return measureRules;
}
See Also