Hi Jacky,
If the values on displayed on the axis are ready for percentage formatting - that is all values are rescaled to the range [0, 1] then you can simply change the formatting to percentage - for example:
NChart chart = nChartControl1.Charts[0];
NBarSeries bar = new NBarSeries();
bar.Values.Add(0.1);
bar.Values.Add(0.2);
bar.Values.Add(0.3);
chart.Series.Add(bar);
NLinearScaleConfigurator scale = chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator as NLinearScaleConfigurator;
scale.LabelValueFormatter = new NNumericValueFormatter("P");
Otherwise you can use the ValueScale property of the scale label style:
NChart chart = nChartControl1.Charts[0];
NBarSeries bar = new NBarSeries();
bar.Values.Add(10);
bar.Values.Add(20);
bar.Values.Add(30);
chart.Series.Add(bar);
NLinearScaleConfigurator scale = chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator as NLinearScaleConfigurator;
scale.LabelStyle.ValueScale = 0.01;
scale.LabelValueFormatter = new NNumericValueFormatter("P");
Hope this helps - let us know if you meet any problems.