PieChart Labels / Legend

[Brian]

I need to specify labels for my PieChart.  As of right now it seems this is not possible.

Would it be possible to create a legend from the rendered chart if we cannot set a specific label?

[Rosy Topchiyska]

Hi Brian,

Thank you for contacting us.

This could be achieved with a ListView control that is data bound to the same collection as the ItemsSource of the PieSeries. You will have to set a custom ListView.ItemTemplate that contains color and information for the corresponding data point. If you create a custom chart palette you will be able to get the right color for a data item depending on its index in the collection.

Unfortunately, at this moment there is a bug with the RadPieChart and the palettes are not applied properly to the series. We will look into this issue and will get back to you as soon as we have a solution.

I have attached a sample project that demonstrates how this it could work, but please note that only the pie chart in the Windows Phone project renders correctly.

I hope this helps.

Regards,
Rosy Topchiyska
Telerik

 

 

[Goh]

Hi, may i know what is the status to specify labels in Pie Chart? it is workable now in Xamarin.Forms?

[Goh]

Hi, may i know what is the status to specify labels in Pie Chart? it is workable now in Xamarin.Forms?

[Ves]

Hi Goh,

You can display labels by setting the ShowLabels property of PieSeries to true.

Best regards,
Ves
Telerik

 

 

[Jeremias]

Hi, I'm having an issue in Android, when I set the palette, the colors are displayed correctly, but the labels are not visible.. Is this still an issue with the chart??

[Jeremias]

additional information, I'm developing in Xamarin Studio, a Xamarin Forms solutions

[Ves]

Hi Jeremias,

The labels use the StrokeColor of the PaletteEntry, so when creating custom palette, please specify both FillColor and StrokeColor:

var palette = new ChartPalette();

palette.Entries.Add(new PaletteEntry(Color.Blue, Color.Black));
palette.Entries.Add(new PaletteEntry(Color.Gray, Color.Black));

Best regards,
Ves
Telerik

[Jeremias]

Excellent, Thanks

[Ian]

Setting the <em>ShowLabels</em> property of PieSeries to true does work but how can I choose to bind the displayed value in the pie sector to some other part of my model other than the numeric variable I've used to define the slice size in my datamodel ?

[Ves]

Hi Ian,

You can take advantage of LabelBinding and LabelFormat properties. The former works just like ValueBinding, retrieving a property you specify from the underlying object and showing it as a label, and the latter serves to accept a format, should you want to display a numeric or date/time value

Best regards,
Ves
Telerik by Progress

[Ian]

Many thanks for info on LabelBinding.

Have you a specific example of the user of LabelFormat , i.e where to place it in the XAML and example formatting syntax.

I tried something like "{0}%" and it broke the XAML.

[Ves]

Hi Ian,

Curly braces in XAML must be preceded by a pair of open-close curly braces i.e. your label format should look like this: {}{0}% In addition, you can apply formatting this way: {}{0:F2}% - this will display values with 2 decimals e.g. 17.00%.
Note, that this will only add percent character after the label, but it will not calculate the actual percentage. You will need to calculate the percentage by yourself and store it in a property to use as a label.

Best regards,
Ves
Telerik by Progress