[RESOLVED] Plotting a line chart problem (In user control)

[pourkascheff]

Hi all.
This is an example code which works properly and plots an xy series of dots/lines.

Public Class Form2
    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
        Label1.Text = Val(Label1.Text) + 1
        Chart1.Series(0).Points.AddXY(Val(Label1.Text), TrackBar1.Value)
    End Sub
End Class

Here's the results safe and easy:


However, to show a line chart in a usercontrol same code (In a try catch) will cause following exception:
"Index was out of range. Must be non-negative and less than size of collection. Parameter name: index" Series1 is OK in term of name, checked.
"A chart element with the name 'Series1' could not be found in the 'SeriesCollection'." Integer id same as example code.

* Both way were tried. Nothing achieved.
Any clues? Is there another way/method to add point in x and y?

[Delaney]

can you post the code in the user control ?

don't you have to put the name of the usercontrol before the name of the control in the code?

yourusercontrolname.Chart1.series ....

[pourkascheff]

can you post the code in the user control ?

Yes sir, But it is nothing much:

Public Class ITEM
    Private Sub Label1_TextChanged(sender As Object, e As EventArgs) Handles Label1.TextChanged
        Try
            chartx.Text = Val(chartx.Text) + 1
            Chart1.Series("Series1").Points.AddXY(Val(chartx.Text), Val(Label1.Text))
        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Critical)
        End Try
    End Sub
End Class

Translasion: Once Label1 value changes, a variable increment will occur and current-value under chartx (represents steps) also shown under x,y.

don't you have to put the name of the usercontrol before the name of the control in the code?

Not sure.

yourusercontrolname.Chart1.series ....

Well, I tried it now, dot after UserControl1 opens a list of properties which none of its controls are not available in it, therefore "UserControl1.Chart1" doesn't exist. I added Chart1 to a TabControl it doesn't make difference right? I'm new to VB.NET behavior/logic.
Update: "Me.Chart1." does exist tho. But same exceptions will occur.

* Is it possible that an option (explicit, strict, compare, infer and etc.) rectifies the matter? It seemed easier at first but it's not... : (

[Delaney]

Ok after checking it comes from the label events. What I guess is that the label event is triggered at some point before the serie is created so you will have to change the philosophy of the filling of the chart. I join my test_sample so you can maybe get some ideas.

done with VS2017 (FW 4.7.2)

test_usercontrol.zip

[pourkascheff]

Well done sir. It finally worked. Thank you. Manual private sub filling_chart function did the thing. Just forget about interpolation in an event people...