ASP.NET Chart Control sorting

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Part 6 - Chart.DataBindTable Example
Part 7 - 3D Charts in ASP.NET
Part 8 Binding XML file to ASP.NET Chart Control



In this video we will discuss ASP.NET Chart Control sorting. This is continuation to Part 8. Please watch Part 8 before proceeding.



The end user should be able to sort chart data by StudentName and TotalMarks in ascending and descending order. To support this we want 2 DropDownLists on the WebForm1.aspx. 

One DropDownList will contain the fields to sort the data by i.e
StudentName
TotalMarks

The other DropDownList will contain the sort direction i.e
Ascending
Descending

With the 2 DropDownLists and the chart control, the design of WebForm1.aspx should be as shown below.


Here is the HTML used in the demo

<table style="font-family: Arial; border: 1px solid black">

<tr>

    <td>

        Sort By :

        <asp:DropDownList ID="ddlSortBy" AutoPostBack="true" runat="server"

            OnSelectedIndexChanged="ddlSortBy_SelectedIndexChanged">

            <asp:ListItem Text="Student Name" Value="StudentName"></asp:ListItem>

            <asp:ListItem Text="Total Marks" Value="TotalMarks"></asp:ListItem>

        </asp:DropDownList>

    </td>

    <td>

        Sort Direction :

        <asp:DropDownList ID="ddlSortDirection" AutoPostBack="true" runat="server"

            OnSelectedIndexChanged="ddlSortDirection_SelectedIndexChanged">

            <asp:ListItem Text="Ascending" Value="ASC"></asp:ListItem>

            <asp:ListItem Text="Descending" Value="DESC"></asp:ListItem>

        </asp:DropDownList>

    </td>

</tr>

<tr>

    <td colspan="2">

        <asp:Chart ID="Chart1" runat="server">

            <Series>

                <asp:Series Name="Series1">

                </asp:Series>

            </Series>

            <ChartAreas>

                <asp:ChartArea Name="ChartArea1">

                </asp:ChartArea>

            </ChartAreas>

        </asp:Chart>

    </td>

</tr>

</table>

and the code for the code-behind file

using System;

using System.Data;

namespace ChartsDemo

{

public partial class WebForm1 : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

        if (!IsPostBack)

        {

            // Use the default sort - Sort by TotalMarks in Ascending order

            GetChartData(null);

        }

    }

    private void GetChartData(string sortExpression)

    {

        DataSet ds = new DataSet();

        // Read the data from XML file into DataSet

        ds.ReadXml(Server.MapPath("~/Students.xml"));

        // Specify the column that contains values for X-AXIS

        Chart1.Series["Series1"].XValueMember = "StudentName";

        // Specify the column that contains values for Y-AXIS

        Chart1.Series["Series1"].YValueMembers = "TotalMarks";

        // Create the DataView

        DataView dataView = ds.Tables[0].DefaultView;

        // Specify how the data should be sorted

        dataView.Sort = string.IsNullOrEmpty(sortExpression) ?

            "TotalMarks ASC" : sortExpression;

        // Set sorted DataView as the DataSource for the Chart control

        Chart1.DataSource = dataView;

        // Finally call DataBind

        Chart1.DataBind();

    }

    protected void ddlSortBy_SelectedIndexChanged(object sender, EventArgs e)

    {

        // Sort the data based on the selections in the DropDownLists

        GetChartData(ddlSortBy.SelectedValue + " " + ddlSortDirection.SelectedValue);

    }

    protected void ddlSortDirection_SelectedIndexChanged(object sender, EventArgs e)

    {

        GetChartData(ddlSortBy.SelectedValue + " " + ddlSortDirection.SelectedValue);

    }

}

}