Display consistently changing value on an ASP.NET web form

Question

I am currently writing a program in C# that constantly outputs random values between 1 and 12 and displays them in a label control on an ASP.NET web form. While the output is successfully written to the web form, it only displays one value. In other words, I want the label output to track the output (display) each value that is produced by the function as written below to produce a consistently changing value:

[WebMethod]
    public static string StreamData()
        {
            string[] value = new string[1]; 

            Random rnd = new Random();

            Thread t = new Thread(delegate ()
            {
                while (true)
                {
                    value[0] = rnd.Next(1, 13) + "";
                }
            });
            t.Start();


            return value[0]; 

        }

I have tried using an AJAX function to pull the data from the function but I am not too sure if I am going about displaying the data in the right way:

     <script type="text/javascript">
    $(function () {
        $.ajax({
            type: 'POST',
            url: 'default.aspx/streamdata',
            data: '',
            contentType: 'application/json; charset=utf-8',
            dataType: 'json',
            success: function (msg) {
                //alert(msg.d);
                $('#<%= lblReading.ClientID %>').html(msg.d);
            }
        });
             });
</script>

The program is being written to test the concept of trending live data from PLCs using TIA Portal 15 with said data obtained from sensor readings across a production line. The idea behind this program is to serve as a proof of concept that real-time data can in fact be displayed and trended in an ASP.NET web environment to be accessed across a range of web-compliant devices. Despite my efforts in displaying random values in this way, my attempts have been thus far unsuccessful, although I am determined to not give up. I researched this method which uses SignalR to achieve something similar to my desired solution, though I am unsure of how to implement it in my case: How to implement real time data for a web page

Could somebody please shed some light on how the above might be achieved?

Many Thanks,

Ben.

First step in your AJAX would be appending your result to your label instead of overwriting it. — AsheraH, Sep 03 '18 at 11:55
But the idea is to display random changing values that can be trended. Temporary storage and display of values such as is proposed by a method of appendage is not what I am looking for. Think of the display as say a tachometer which displays speed output values, for example. — BStanway, Sep 03 '18 at 12:35

score -1 · Accepted Answer · answered Sep 03 '18 at 11:48

-1

Your requirement can be accomplished in ASP.Net web forms using SignalR. Please take a look at this small tutorial on how to do that, Adding SignalR to an ASP.NET WebForms Project

answered Sep 03 '18 at 11:48

Nouman

591
6
14

It is frowned upon to answer a question with a link to a tutorial. Please read https://stackoverflow.com/help/how-to-answer to get more information on how to format a good answer. – JanWillem Huising Sep 03 '18 at 11:58

Display consistently changing value on an ASP.NET web form

1 Answers1