Show Label When Value is Zero

[Gaurab]

On my chart (see attached), the value is zero where the green arrow is.  I want the label to show "Current: 0" there.  Instead, it shows nothing.  The value is actually 0 and not null.  My users are going to think it's "missing".  How can I get the label to show?

[Stamo Gochev]

Hi,

This is a bug in Bar and ColumnSeries, so I have logged it in our Feedback portal, where you can vote and track its progress. I have also update your Telerik points for this bug report.

There is a workaround, whose idea follows these steps:

1. Create a constant variable which is a very small number  like 0.00000000001 and use it as a marker
2. When you populate the SeriesItems, check if the next item's value is equal to 0 (zero) and if this is the case, change its value to the constant variable in step 1.
3. Use the ClientTemplate property of the LabelsAppearance to switch the item's label - check if the item's values is equal to INVALID_VALUE (the constant in step 1) and show a label with the value "0" in this case:

   const decimal SPECIAL_VALUE = 0.000000000000000000000001M;
   BarSeries bar1 = new BarSeries();
   bar1.LabelsAppearance.ClientTemplate = "#= value === " + SPECIAL_VALUE + " ? 0 : value #";

I also attach a sample page, where I have demonstrated this approach. You can use it as a reference and apply the idea in your scenario.

Regards,
Stamo Gochev
Telerik