How can I pass a C# variable value to javascript to work with amcharts?

StackOverflow https://stackoverflow.com/questions/12241756

Question

I am trying to pass a variable with a json string from C# to javascript where I am trying to use that information to draw an amchart column chart. However, when I try to access the variable that stores the json string from javascript, I receive the following error:

Compiler Error Message: BC30451: 'sjson' is not declared. It may be inaccessible due to its protection level.

at line,

var chartData = '<%=sjson%>';

Here is all of my code:

C#: 

    public partial class Default3 : System.Web.UI.Page
    {
        public string sjson;
        protected void Page_Load(object sender, EventArgs e)
        {
            ArrayList conRc = new ArrayList();


            for (int i = 0; i < 10; i++)
            {

                conRc.Add(new Confidence(i.ToString(), (i + 10).ToString()));

            }

            foreach (object obj in conRc)
            {
                Confidence cnLv = (Confidence)obj;
                Response.Write(cnLv.Ip + " - " + cnLv.Count.ToString());
                Response.Write("</br>");
            }

            System.Web.Script.Serialization.JavaScriptSerializer oSerializer = new System.Web.Script.Serialization.JavaScriptSerializer();
            sjson = oSerializer.Serialize(conRc);

        }
    }

HTML:

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
    <html>

        <head>

            <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
            <title>amCharts examples</title>
            <link rel="stylesheet" href="http://localhost/amcharts/images/style.css" type="text/css">
            <script src="http://localhost/amcharts/amcharts.js" type="text/javascript"></script>         
            <script type="text/javascript">

                var chart;

                var chartData = '<%=sjson%>'; //[{ "Ip": "0", "Count": "10" }, { "Ip": "1", "Count": "11" }, { "Ip": "2", "Count": "12" }, { "Ip": "3", "Count": "13" }, { "Ip": "4", "Count": "14" }, { "Ip": "5", "Count": "15" }, { "Ip": "6", "Count": "16" }, { "Ip": "7", "Count": "17" }, { "Ip": "8", "Count": "18" }, { "Ip": "9", "Count": "19"}];



                AmCharts.ready(function () {
                    // SERIAL CHART
                    chart = new AmCharts.AmSerialChart();
                    chart.dataProvider = chartData;
                    chart.categoryField = "Ip";
                    chart.startDuration = 1;

                    // AXES
                    // category
                    var categoryAxis = chart.categoryAxis;
                    categoryAxis.labelRotation = 90;
                    categoryAxis.gridPosition = "Count";

                    // value
                    // in case you don't want to change default settings of value axis,
                    // you don't need to create it, as one value axis is created automatically.

                    // GRAPH
                    var graph = new AmCharts.AmGraph();
                    graph.valueField = "Count";
                    graph.balloonText = "[[category]]: [[value]]";
                    graph.type = "column";
                    graph.lineAlpha = 0;
                    graph.fillAlphas = 0.8;
                    chart.addGraph(graph);

                    chart.write("chartdiv");
                });
            </script>

        </head>

        <body>
            <div id="chartdiv" style="width: 100%; height: 400px;"></div>
        </body>

    </html>
Was it helpful?

Solution

You seem to have missed something very fundamental here.

The first line of an aspx have should look like this:

<%@ Page Language="C#" Inherits="Default3 " Codebehind="Default3.aspx.cs" %>

If you don't have that line, your aspx page will not use the same class, and you can't access its public properties.

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