异步asp.net表

Question

I am populating an asp.net table (up to 64 rows) with data from a SQL query and multiple web requests (1 per row). The first 4 columns are populating quickly, however the last 2 take 6 seconds per web request. I would like the last 2 columns to display a loading gif and update once the web calls are completed. Because credentials are passed in the web call I would like to make the calls in the server side.

Additionally, I would like to make multiple web requests in parallel. I am looking into tasking, however I am not sure how to allow the table to complete while tasking specific columns.

I'm not attached to the way I am doing this, however I'm still new to programming and am most familiar with C# and asp.net.

Right now it looks something like:

Ajax Page

<div>
    <form id="ajaxForm" name="ajaxForm" runat="server">
        <asp:table id="aspTbl" runat="server" />
    </form>
</div>

With the c# being:

//SQL Connection
SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.AppSettings["webConfigConnection"]);
con.Open();
SqlCommand cmd = new SqlCommand("Select name, type, location, IP from tbl", con)
SqlDataReader sdr = cmd.ExecuteReader();

while (sdr.Read()
{

    //web requeststring
    sURL;
    sURL = "http://" + sdr.GetValue(4).ToString()  + "WebRequestURL";
    WebRequest request;
    request = WebRequest.Create(sURL);
    request.Method = "GET";
    WebResponse response = request.GetResponse();
    StreamReader Report = new StreamReader(response.GetResponseStream());
    string ReportString = Report.ReadToEnd().ToString();
    Response.Close();

    //Populate Table
    TableCell tc1 = new TableCell();
    TableCell tc2 = new TableCell();
    TableCell tc3 = new TableCell();
    TableCell tc4 = new TableCell();
    tc1.Text = sdr.GetValue(0).ToString();
    tc2.Text = sdr.GetValue(1).ToString();
    tc3.Text = sdr.GetValue(2).ToString();
    tc4.Text = sdr.GetValue(3).ToString();
    tc5.Text = ReportString.SubString(paramaters);
    tc6.Text = ReportString.SubString(other paramaters);
    TableCell[] tcRow = new TableCell[] { tc1, tc2, tc3, tc4, tc5, tc6 };
    tr.Cells.AddRange(tcRow);
    asptbl.Rows.Add(tr);

}

The goal is to get T5 and T6 to initially populate with the loading GIF and update asynchronously with the substring once available.

Edit: 6/10/2015

Thanks for the advice. It works for running the web requests in parallel, however it still requires them to all complete before posting, which I realized over the weekend is not something I can avoid running this on the server end. What I'll be trying is to have the cells make a jquery ajax call for the web request and update the cells so that the columns 1-4 can load instantly and columns 5 and 6 will populate once available. Will provide an update with how it works.

Edit: 6/10/2015 #2

I updated to populate the cells empty and upon completion of the ajax call that hits calls this, I loop through the cells to populate them with javascript. The issue I ran into now is that the cell that I am trying to populate is calling the same form a large number of times simultaneously and the web requests are queuing up.

Answer 1

Just if its relevant,

List<Task> TaskList = new List<Task>();   

Task PushRow(Table tbl, string name,string type,string location,string IP ){ 
    Task.Run(()=>{

       //Add code for webdownload and table row adding

    });
}

Then call this function inside while loop and store the result in a list TaskList of type List<Task>. Use

Task.WaitAll(TaskList.ToArray());

To wait for all task to be completed in after the loop.

Answer 2

I ended up creating the table with empty web request cells. Once the page loads, the client calls the web request for each cell and updates the cells. The only thing I couldn't figure out was how to update 2 cells with one web call, but the solution in place works.

Thanks for taking a look.