I assume when you say that you don't have a value, you mean that the property of the business object is nullable and returns null instead of a valid value such as 0.
In this case, you can hide each item that corresponds to an empty value after the chart has been data bound:
sender, EventArgs e)
item.Label.Visible = !item.Empty;
If you want to hide items that actually correspond to 0 rather than null, you should, naturally, set the labels' visibility depending on whether the item.YValue property is 0.
All the best,
the Telerik team
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