Thanks for writing. The AddItem method of the Series has different overloads, most of which create a ChartSeriesItem
in the background for you. Since none of these works for your case, the best solution is to just create a ChartSeriesItem
instance on your own, set it's appropriate values and add it to the series. The following code demonstrates this technique:
|this.radChart1.Series.AddItem(new ChartSeriesItem(10, 20));
Once you set the X value of even a single item, the RadChart will expect all chart items to have X values, which will lead to incorrect rendering of the items with no X value set.
If you have further questions, just drop us a line.
the Telerik team