Dynamically populate ASP.NET Gridview from jQuery AJAX call

Question

Error:

cannot refer to an instance member of a class within a shared method

I'm working on a web application that pulls data from a MSSQL server on the backened. Calling my web method from ajax isn't the issue, it's displaying the data once it has been received.

I have the following gridview on my report page:

<asp:GridView ID="gridReport" runat="server"></asp:GridView>

The web method that is pulling the data from the DB is called DBManager.asmx, it is declared as follows (this is called via ajax each time a drop-down is changed):

<WebMethod()> _
Public Function GetSpecificReport(ByVal strFilter As String) As String()

(it is NOT the code-behind file for the report page) The data being returned from the DB is currently in a DataSet (variable name: ds).

Is there any way to assign the DataSource for that GridView to the DataSet pulled from the .asmx file, or a nice workaround that I could try? I've tried creating shared methods in the code-behind report page with no luck, as well as putting the GetSpecificReport method inside the code-behind.

Thanks for the help, let me know if I should give more info or post more code.

Answer 1

I would offer 3 suggestions:

First and foremost, using something like telerik grid that allows you to return JSON from your webmethod and bind directly to that json: http://www.telerik.com/products/aspnet-ajax/grid.aspx

That said, I whipped up a small example where you can render a gridview in your webmethod and re-emit the HTML.

You can also just draw your table in HTML using RenderControl:

Here is a simplified example that re-draws the control using jquery.ajax without any updatepanel or etc. Updatepanel probably works better though!

ASPX:

   <%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
    CodeBehind="Default.aspx.cs" Inherits="TymeJVTest._Default" %>

<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">
</asp:Content>
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
     <script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
    <script>

        function blag() {
            var gridID = "<%= GridView1.ClientID %>";
            $.ajax({
                type: "POST",
                data: {},
                contentType: "application/json;charset=utf-8",
                dataType: "json",
                async: true,
                url: "Default.aspx/GetSomeData",
                success: function (data) {
                    //not sure why this is data.d , but what the hey
                    var theHtml = data.d;
                    $("#" + gridID).html(theHtml);
                },
                failure: function () {
                    alert("Sorry,there is a error!");
                }
            });               
        }
    </script>
    <h2>
        Welcome to ASP.NET!
    </h2>
    <p>
        To learn more about ASP.NET visit <a href="http://www.asp.net" title="ASP.NET Website">www.asp.net</a>.
    </p>
    <p>
        You can also find <a href="http://go.microsoft.com/fwlink/?LinkID=152368&amp;clcid=0x409"
            title="MSDN ASP.NET Docs">documentation on ASP.NET at MSDN</a>.
    </p>
    <asp:GridView ID="GridView1" runat="server">
    </asp:GridView>
    <a href="#"onclick="blag();" >Test</a>
</asp:Content>

CS:

 public partial class _Default : System.Web.UI.Page
    {        
        protected void Page_Load(object sender, EventArgs e)
        {

            int[] theObject = {1, 2, 3, 4};

            GridView1.DataSource = theObject;
            GridView1.DataBind();
        }


        [WebMethod]
        public static String GetSomeData()
        {
            GridView gv = new GridView();
            System.IO.StringWriter stringWriter = new System.IO.StringWriter();
            HtmlTextWriter htmlWriter = new HtmlTextWriter(stringWriter);
            int[] someNewData = {10, 11, 12, 13, 14};
            gv.DataSource = someNewData;
            gv.DataBind();

            gv.RenderControl(htmlWriter);
            return stringWriter.ToString();
        }
    }

This will create a replacement gridview on the server, render it to html, then transmit it back.

You could also use something like AngularJS and just keep a piece of JSON that your server updates, and use this to bind to a grid in real-time with angular.

Answer 2

I think you can achieve what you want without too much changes using an updatepanel.

http://msdn.microsoft.com/en-gb/library/bb399001.aspx

Basically populate your grid on page load or whatever suits you then do refreshes using updatepanel.