Configuring Axis Label Format

In the XamDataChart™ control, axis labels always display simple text without any formatting applied to them. However, you can change the format of axis labels by setting a formatting string on the Label property of the AxisFormatLabelEventArgs in a handler for the Axis.FormatLabel event.

For example, if you are plotting monetary data along y-axis, the default labels will simply display a decimal representation of your monetary values. If you want to display these values with currency symbols, you need to use C format specifier, followed by a number, specifying decimal precision. For detailed information on .NET Framework composite format strings please refer to the following online resources:

The following code example shows how to format labels on CategoryXAxis and NumericYAxis using date formatting and currency formatting:

In XAML:

<ig:XamDataChart.Axes>
    <ig:CategoryXAxis FormatLabel="OnCategoryAxisFormatLabel" />
    <ig:NumericYAxis FormatLabel="OnPricesAxisFormatLabel" />
    <ig:NumericYAxis FormatLabel="OnVolumeAxisFormatLabel" />
</ig:XamDataChart.Axes>

This subscribes the FormatLabel event to event handlers for each axis. These event handlers are then written in the code behind in the same way as they are in the code snippet below.

In C#:

var commonAxis = new CategoryXAxis();
commonAxis.FormatLabel += OnCategoryAxisFormatLabel;

var pricesAxis = new NumericYAxis();
pricesAxis.FormatLabel += OnPricesAxisFormatLabel;

var volumeAxis = new NumericYAxis();
volumeAxis.FormatLabel += OnVolumeAxisFormatLabel;

...

private void OnVolumeAxisFormatLabel(object sender, AxisFormatLabelEventArgs e)
{
    e.Label = string.Format("{0:#,0} K", (double)e.Item);
}

private void OnPricesAxisFormatLabel(object sender, AxisFormatLabelEventArgs e)
{
    e.Label = string.Format("{0:C1}", (double)e.Item);
}

private void OnCategoryAxisFormatLabel(object sender, AxisFormatLabelEventArgs e)
{
    var dataItem = (Sale)e.Item;
    e.Label = string.Format("{0:MMM dd}", dataItem.Date);
}

Note

Note:

Type of Item property of AxisFormatLabelEventArgs is always of type double for all numeric axes. However, for category axes, the type of Item property is the same as the data item’s type. In this case, the Item is a Sale object because a list of Sale objects was bound to the ItemsSource property of the CategoryXAxis.

The following image shows how the XamDataChart control might look with formatted date on CategoryXAxis and formatted currency on NumericYAxis.

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Configuring Axis Label Format

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