TreeMapColorizerBase.ValueProvider Property

Gets or sets a provider of values the colorizer uses to determine colors for treemap items.

Namespace: DevExpress.XtraTreeMap

Assembly: DevExpress.XtraTreeMap.v20.2.dll

NuGet Package: DevExpress.TreeMap

Declaration

C#

[DefaultValue(null)]
public IColorizerValueProvider ValueProvider { get; set; }

VB.NET

<DefaultValue(Nothing)>
Public Property ValueProvider As IColorizerValueProvider

Property Value

Type	Default	Description
IColorizerValueProvider	*null*	An object of a class that implements the IColorizerValueProvider interface.

Remarks

Treemap colorizers uses item values (TreeMapItem.Value, TreeMapFlatDataAdapter.ValueDataMember, or HierarchicalDataMapping.ValueDataMember) to determine colors. You can use the ValueProvider property to specify a custom value source for a colorizer.

If ValueProvider is specified, a custom colorizer also uses its returned values to determine colors.

The following example shows how to make a treemap colorizer determine item colors based on the bound data source’s “HPI” row values:

C#

((TreeMapColorizerBase)treeMapControl1.Colorizer).ValueProvider = new ColorizerValueProvider();
//...
public class ColorizerValueProvider : IColorizerValueProvider {
    double IColorizerValueProvider.GetValue(IHierarchicalItem item, int itemIndex) {
        DataRowView row = item.Tag as DataRowView;
        if (row != null)
            return (double)row["HPI"];
        return 0;
    }
}

VB.NET

CType(treeMapControl1.Colorizer, TreeMapColorizerBase).ValueProvider = New ColorizerValueProvider()
'...
Public Class ColorizerValueProvider
    Inherits IColorizerValueProvider

    Private Function GetValue(ByVal item As IHierarchicalItem, ByVal itemIndex As Integer) As Double
        Dim row As DataRowView = TryCast(item.Tag, DataRowView)
        If row IsNot Nothing Then Return CDbl(row("HPI"))
        Return 0
    End Function
End Class

View Example

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the ValueProvider property.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

treemap-how-to-use-a-custom-value-source-for-a-colorizer/CS/Form1.cs#L18

    ((TreeMapFlatDataAdapter)treeMapControl1.DataAdapter).DataSource = CreateDataSet();
    ((TreeMapColorizerBase)treeMapControl1.Colorizer).ValueProvider = new ColorizerValueProvider();
}

VB.NET

treemap-how-to-use-a-custom-value-source-for-a-colorizer/VB/Form1.vb#L20

    CType(treeMapControl1.DataAdapter, TreeMapFlatDataAdapter).DataSource = CreateDataSet()
    CType(treeMapControl1.Colorizer, TreeMapColorizerBase).ValueProvider = New ColorizerValueProvider()
End Sub