CODEWITHSUNDEEP
c#winformseventschartszooming
hrh
hrh

Reputation: 658

How to get the zoom event of a C# chart

I have a chart (the standard chart that comes with win-forms visual studio) that I've set up zooming on. Every time this chart is zoomed I would like to run a function, however I cannot find an event that is triggered on zoom. I looked though the list of events and the only one that I thought may work was "AxisViewChanged", however this is triggered on many changes and I don't know how to single out just the zoom changes. Is there some zoom event I'm missing? or does this just not exist?

Upvotes: 3

Views: 5872

Answers (1)

parapura rajkumar
parapura rajkumar

Reputation: 24403

You can do something like this

    double oldSelStart = -1;
    double oldSelEnd = -1;
    private void chart1_AxisViewChanged(object sender, ViewEventArgs e)
    {
        double newSelStart = chart1.ChartAreas["Default"].CursorX.SelectionStart;
        double newSelEnd = chart1.ChartAreas["Default"].CursorX.SelectionEnd;
        const double TOLERANCE = 0.1;

        if (Math.Abs(oldSelEnd - newSelEnd) > TOLERANCE || Math.Abs(newSelStart - oldSelStart) > TOLERANCE)
        {
            oldSelStart = newSelStart;
            oldSelEnd = newSelEnd;

            //Zoom has actually changed do your stuff
        }
    }

Basically you remember your old zoom ranges and handle AxisViewChanged yourself and determine if the zoom has actually changed

Upvotes: 4

Related Questions