Graph doubling, tripling the series. VB .NET

Question

I'm having a hard time solving this problem. After many attempts, I couldn't solve it.

I have a form that has a Chart and two radiobuttons and a Button. In Radiobutton I have 2D and 3D options. When I select for example 3D the graph is being drawn. If I then choose the 2D option, the graph is drawn in 2D, but the data is being duplicated, tripled and so on each time I ask to draw the graph. I used the Chart1.Series.Clear() command but it is not working. Follow the code. The graph has two series. At the beginning of the program I define the two series:

        Public s As New Series ' column
        Public s1 As New Series 'bar

        If RadioButton4.Checked Then             
			Chart1.ChartAreas(0).Area3DStyle.Enable3D = True         
		Else             
			Chart1.ChartAreas(0).Area3DStyle.Enable3D = False         
		End If

        Chart1.Series.Clear()
        s.Name = "Vendas"
        With s
            .IsValueShownAsLabel = True
            .BorderWidth = 4
            .Color = Color.DarkGreen
            .LegendText = "actual sales"

            .Points.AddXY("Janeiro", 150)
            .Points.AddXY("Fevereiro", 140)
            .Points.AddXY("Março", 110)
            .Points.AddXY("Abril", 125)
            .Points.AddXY("Maio", 140)
            .Points.AddXY("Junho", 155)
        End With
        Chart1.Series.Add(s) 'add the series to the chart

        
        s1.Name = "previsao"
        With s1
            .BorderWidth = 4
            .Color = Color.FromArgb(255, 155, 0) ' amarelo
            .LegendText = "Sales forecast"
            .IsValueShownAsLabel = True
            .Points.AddXY("Janeiro", 130)
            .Points.AddXY("Fevereiro", 145)
            .Points.AddXY("Março", 100)
            .Points.AddXY("Abril", 120)
            .Points.AddXY("Maio", 120)
            .Points.AddXY("Junho", 140)
        End With
        Chart1.Series.Add(s1) 'add the series to the chart
        ```

Answer 1

Hi @José Carlos ,

If you define s and s1 as global variables, then every time the code snippet containing adding data points is called, data points are repeatedly added to these global variables and added to the chart again. This will result in an increased amount of data in the chart.

To avoid this, you can define s and s1 as local variables, so that each time the snippet is called new local variables are created and data points are added to these local variables. This ensures that each call will use a new series object and data points, without adding data repeatedly.

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        If RadioButton4.Checked Then
            Chart1.ChartAreas(0).Area3DStyle.Enable3D = True
        Else
            Chart1.ChartAreas(0).Area3DStyle.Enable3D = False
        End If

        Chart1.Series.Clear()

        Dim s As New Series()
        s.Name = "Vendas"
        With s
            .IsValueShownAsLabel = True
            .BorderWidth = 4
            .Color = Color.DarkGreen
            .LegendText = "actual sales"

            .Points.AddXY("Janeiro", 150)
            .Points.AddXY("Fevereiro", 140)
            .Points.AddXY("Março", 110)
            .Points.AddXY("Abril", 125)
            .Points.AddXY("Maio", 140)
            .Points.AddXY("Junho", 155)
        End With
        Chart1.Series.Add(s)

        Dim s1 As New Series()
        s1.Name = "previsao"
        With s1
            .BorderWidth = 4
            .Color = Color.FromArgb(255, 155, 0) ' amarelo
            .LegendText = "Sales forecast"
            .IsValueShownAsLabel = True
            .Points.AddXY("Janeiro", 130)
            .Points.AddXY("Fevereiro", 145)
            .Points.AddXY("Março", 100)
            .Points.AddXY("Abril", 120)
            .Points.AddXY("Maio", 120)
            .Points.AddXY("Junho", 140)
        End With
        Chart1.Series.Add(s1)

    End Sub

Best Regards.

Jiachen Li

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