Fratyx - 9 months ago 61

C# Question

I found a weird behavior in MS Chart for Windows Forms.

Let's say I want to have a scatter plot with two points (1,10) and (1,20). I can do that in this way:

`....`

Series series = new Series();

series.ChartType = SeriesChartType.Point;

double[] x = { 1, 1 };

double[] y = { 10, 20 };

series.Points.DataBindXY(x, y);

That works fine. But now I want the same result, but both x-values should be

`0`

`double[] x = { 0, 0 };`

double[] y = { 10, 20 };

series.Points.DataBindXY(x, y);

In that case the chart control creates two data points at 'autogenerated' x positions 1 and 2. It just ignores the given x-values. It is the same behavior if I use

`series.Points.AddXY(0, 10);`

series.Points.AddXY(0, 20);

I get the same effect for more than two data points. So it turns out that scatter plot does not work if not at least one x-value is nonzero.

I think a possible workaround would be to use multiple series, but that is inacceptable.

Does anyone have a explanation for this behavior or a solution for this problem?

Answer

I found a solution by myself:

You have to add

```
series.CustomProperties = "IsXAxisQuantitative=True";
```

to your code. So the x-values really are treated as values. I don't know why this is not self-evident if I use the BindXY function.