exploded pie

Question

Hi,

I have created a pie chart which explodes whenever I click a slice.

The thing is, whenever the user clicks the exploded slice again, I want it to change the Exploded property to false.

How can I check the slice's custom property?  I use postback and I think the property is reset to false whenever I click a slice.

This is my c# code:

protected void Chart1_Click(object sender, ImageMapEventArgs e)
        {
            int pointIndex = int.Parse(e.PostBackValue);
            Chart chartCtl = (Chart)Panel1.FindControl("Chart1");
            Series series = chartCtl.Series["Series1"];
            chartCtl.DataBind();
            if (pointIndex >= 0 && pointIndex < series.Points.Count)
            {
                series.Points[pointIndex].CustomProperties += "Exploded=true";
            }
        }

and this is what I wrote for the Onload function:

            Chart chartCtl = (Chart)Panel1.FindControl("Chart1");
            Series series = chartCtl.Series["Series1"];

            series.PostBackValue = "#INDEX";

Answer 1

Hi qsoft_developer,

you can use mouse down event as follows

Private Sub chart1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles chart1.MouseDown

Dim result As HitTestResult = chart1.HitTest(e.X, e.Y)
            Dim exploded As Boolean

            If result.PointIndex = -1 Then Exit Sub

            If chart1.Series(0).Points(result.PointIndex).CustomProperties = "Exploded=true" Then
                exploded = True
            Else
                exploded = False
            End If

            Dim point As DataPoint
            For Each point In chart1.Series(0).Points
                point.CustomProperties = ""
            Next point

            If exploded Then
                Return
            End If

            If result.ChartElementType = ChartElementType.DataPoint Then
                point = chart1.Series(0).Points(result.PointIndex)
                point.CustomProperties = "Exploded = true"
            End If

            If result.ChartElementType = ChartElementType.LegendItem Then
                point = chart1.Series(0).Points(result.PointIndex)
                point.CustomProperties = "Exploded = true"
            End If

End Sub

---

Sandeep J. Sharma (eZee Technosys)

Answer 2

Thank you very much for your response.

I now have another issue i need to solve with the exploded pie.

In my dashboard, I have the pie chart which the user can click on and make it explode, but I also have other charts (column, line charts etc.).

I would like to change the color of the other charts according to the pie slice I clicked on.

The problem is I am using 'BrightPastel' palette in my aspx code, and I can't seem to retrieve the color element of the selected slice from the codebehind (c#).

Does anyone have a solution for this?

 

Answer 3

Hi

You can try this 

Dim result As HitTestResult = chart1.HitTest(e.X, e.Y)

chart2.series(0).color = result.Series().Color

---

Sandeep J. Sharma (eZee Technosys)

Answer 4

Thanks for your reply, but I tried converting to code to c# and I received the following error message:

Error 5 'System.Web.UI.WebControls.ImageMapEventArgs' does not contain a definition for 'X' and no extension method 'X' accepting a first argument of type 'System.Web.UI.WebControls.ImageMapEventArgs' could be found (are you missing a using directive or an assembly reference?)

This is my c# code:

HitTestResult result = chart1Ctl.HitTest(e.X, e.Y);

and of course, I am using the following namespace:

using System.Web.UI.DataVisualization.Charting;
After a quick google search I found this: http://msdn.microsoft.com/en-us/library/dd467422.aspx

I am developing in asp.ne 3.5 framework, and as I understand from this article, HitTestResult is only supported in .net 4.0 framework.

Is there maybe a different solution for me? Am I missing something?