AxisLabel.Formatter Property

Gets or sets an object that formats axis labels.

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v20.2.dll

NuGet Packages: DevExpress.Charts, DevExpress.WindowsDesktop.Charts

Declaration

C#

[Browsable(false)]
public IAxisLabelFormatter Formatter { get; set; }

VB.NET

<Browsable(False)>
Public Property Formatter As IAxisLabelFormatter

Property Value

Type	Description
IAxisLabelFormatter	An object of a class that implements the IAxisLabelFormatter interface.

Remarks

Use the Formatter property if you need to generate text strings for axis labels based on a custom condition or change an order of magnitude of axis label values.

Formatter has higher priority than the AxisLabel.TextPattern property value. For this reason, the AxisLabel.TextPattern value is ignored if Formatter is specified.

Example

Perform the steps below to create a custom formatter for axis labels:

• Create a class that inherits the IAxisLabelFormatter interface and implement the interface’s GetAxisLabelText method.
• Assign the newly created class instance to the AxisLabel.Formatter property.

How to: Format Numeric Axis Labels

This example shows how to apply a custom format to a numeric axis’s labels.

A formatter applies to axis labels:

A formatter does not apply to axis labels:

C#

private void OnFormLoad(object sender, EventArgs e) {
    XYDiagram diagram = (XYDiagram)chartControl1.Diagram;
    AxisLabelFormatter formatter = new AxisLabelFormatter();
    diagram.AxisX.Label.Formatter = formatter;
    diagram.AxisY.Label.Formatter = formatter;
}
public class AxisLabelFormatter : IAxisLabelFormatter {
    public string GetAxisLabelText(object axisValue) {
        return Convert.ToString((double)axisValue / 1000);
    }
}

VB.NET

Private Sub OnFormLoad(ByVal sender As Object, ByVal e As EventArgs)
    Dim diagram As XYDiagram = CType(chartControl1.Diagram, XYDiagram)
    Dim formatter = New AxisLabelFormatter
    diagram.AxisX.Label.Formatter = formatter
    diagram.AxisY.Label.Formatter = formatter
End Sub

Public Class AxisLabelFormatter
    Inherits IAxisLabelFormatter

    Public Function GetAxisLabelText(ByVal axisValue As Object) As String
        Return Convert.ToString(CDbl(axisValue) / 1000)
    End Function
End Class

How to: Format Date-Time Axis Labels

This example shows how to format the date-time axis labels as follows:

A formatter applies to the x-axis’s labels:

A formatter does not apply to axis labels:

C#

private void Form1_Load(object sender, EventArgs e) {

    XYDiagram diagram = chartControl.Diagram as XYDiagram;

    // Configure scale options.
    DateTimeScaleOptions dateTimeScaleOptions = diagram.AxisX.DateTimeScaleOptions;          
    dateTimeScaleOptions.ScaleMode = ScaleMode.Continuous;
    dateTimeScaleOptions.GridAlignment = DateTimeGridAlignment.Day;
    dateTimeScaleOptions.GridSpacing = 7;
    dateTimeScaleOptions.WorkdaysOnly = true;

    // Apply a custom format to axis labels.
    AxisLabel axisLabel = diagram.AxisX.Label;
    axisLabel.Formatter = new AxisLabelFormatter();

}
public class AxisLabelFormatter : IAxisLabelFormatter {
    public string GetAxisLabelText(object axisValue) {
        DateTime value = (DateTime)axisValue;
        return ((value.Day >= 1) && (value.Day <= 7)) ? $"{value.ToString("MMM, d")}" : $"{value.Day}";
    }
}

VB.NET

Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)

    Dim diagram As XYDiagram = TryCast(chartControl.Diagram, XYDiagram)

    ' Configure scale options.
    Dim dateTimeScaleOptions As DateTimeScaleOptions = diagram.AxisX.DateTimeScaleOptions
    dateTimeScaleOptions.ScaleMode = ScaleMode.Continuous
    dateTimeScaleOptions.GridAlignment = DateTimeGridAlignment.Day
    dateTimeScaleOptions.GridSpacing = 7
    dateTimeScaleOptions.WorkdaysOnly = True

    ' Apply a custom format to axis labels.
    Dim axisLabel As AxisLabel = diagram.AxisX.Label
    axisLabel.Formatter = New AxisLabelFormatter

End Sub

Public Class AxisLabelFormatter
    Inherits IAxisLabelFormatter

    Public Function GetAxisLabelText(ByVal axisValue As Object) As String
        Dim value As Date = axisValue
        Return If(value.Day >= 1 AndAlso value.Day <= 7, $"{value.ToString("MMM, d")}", $"{value.Day}")
    End Function
End Class