Dynamically adjusting Y Axis in DevExpress XtraCharts for WinForms

Question

In DevExpress XtraCharts for WinForms, is there a way to have the Y Axis adjust automatically as a user scrolls left and right through the data (so that the data that is currently displayed on the screen fills most of the chart)?

If not automatically are there any demos or would someone have any pointers on how to do this?

You can see this effect happening on this video as the user scrolls left and right the Y-Axis changes: https://www.youtube.com/watch?v=HmA6vANrKKk

Answer 1

According to DevExpress tech support, you have to do it yourself:

"It is necessary to calculate and set Axis Y range manually as described in the Auto adjust Y-Axis range when scrolling on zooming on X-Axis thread. Please try this solution and let me know if you need an additional assistance with this solution implementation."

I also had to add the following statement to get the Y-Axis changes to show up:

stockView.AxisY.VisualRange.SideMarginsValue = 0 

Answer 2

Just set the Axis.VisualRange.Auto property to true to specify that the minimum and maximum axis values are calculated automatically based upon the series being drawn.

Answer 3

Maybe this helps some. The following code solves 2 issues: a) updating of yAxis on main ChartControl when zooming or scrooling, and b) updating the same when adjusting the range on an associated RangeControl.

I use a RangeControl in addition to my ChartControl and strangely the event RangeChanged of RangeControl is raised even when you zoom or scroll on the main chart. This should not be and stanger even the opposite does not hold true: When changing the range of RangeControl none of the events of ChartControl are raised. What complicates things even further is RangeChanged of RangeControl runs on a background thread.

    private void RangeControlOnRangeChanged(object sender, RangeControlRangeEventArgs range)
    {
        var measureUnit = ((XYDiagram)chartControl.Diagram).AxisX.DateTimeScaleOptions.MeasureUnit;
        var origin = default(DateTime);
        DateTime minDt, maxDt;

        switch (measureUnit)
        {
            case DateTimeMeasureUnit.Millisecond:
                minDt = origin.AddMilliseconds((double) range.Range.Minimum);
                maxDt = origin.AddMilliseconds((double) range.Range.Maximum);
                break;

            case DateTimeMeasureUnit.Second:
                minDt = origin.AddSeconds((double) range.Range.Minimum);
                maxDt = origin.AddSeconds((double) range.Range.Maximum);
                break;

            case DateTimeMeasureUnit.Minute:
                minDt = origin.AddMinutes((double) range.Range.Minimum);
                maxDt = origin.AddMinutes((double) range.Range.Maximum);
                break;

            case DateTimeMeasureUnit.Hour:
                minDt = origin.AddHours((double) range.Range.Minimum);
                maxDt = origin.AddHours((double) range.Range.Maximum);
                break;

            case DateTimeMeasureUnit.Day:
                minDt = origin.AddDays((double) range.Range.Minimum);
                maxDt = origin.AddDays((double) range.Range.Maximum);
                break;

            case DateTimeMeasureUnit.Year:
                minDt = origin.AddYears((int)(double) range.Range.Minimum);
                maxDt = origin.AddYears((int)(double) range.Range.Maximum);
                break;

            default:
                throw new NotImplementedException();
        }

        var visibleDataPoints = DataSeries.Where(x => x.TimeStamp >= minDt && x.TimeStamp <= maxDt);
        var newMinValue = visibleDataPoints.Min(x => x.Value);
        var newMaxValue = visibleDataPoints.Max(x => x.Value);

        chartControl.BeginInvoke(new Action(() => ((XYDiagram)chartControl.Diagram).AxisY.VisualRange.SetMinMaxValues(newMinValue, newMaxValue)));
    }

Note that DataSeries here is a collection that implements IList, where DataPoint is struct that holds a DateTime time stamp and a value of type double. But the binding can be done in a myriads of ways. Also note that here you don't even need to hook up Scroll or Zoom events because of the above mentioned oddity in that the RangeChanged event of RangeControl is raised when you scroll or zoom.

I find some of the design and some lacking core features of the DevExpress WinForms charting library extremely embarrassing, given they allow for the most detailed little items to be adjusted while some hugely important features are missing and/or still have not been fixed/added years after they were brought up by users. Maybe I am the only one to complain but I felt it should be voiced.

Answer 4

Try below code：

diagram.DependentAxesYRange = DefaultBoolean.True;
diagram.AxisY.WholeRange.AlwaysShowZeroLevel = false;