Paging, Selecting, Deleting, Editing and Sorting in the ASP.NET GridView Control with Keyboard Shortcuts

#define NET20
using System;
using System.Web;
using System.Collections;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Web.Script;
using System.Web.Script.Services;
using System.Collections.Generic;
using System.Text;

/// <summary>
/// Webservice support for AjaxGrid (using JSON format).
/// These calls are performed synchronously
/// No async handler for JSON is currently available (see http://forums.asp.net/t/1139582.aspx)
/// 
/// These methods all extract the user profile and then call AjaxGrid methods
/// Most call either Repaint (paint complete grid) or RepaintData (repaint only data)
/// and return the string to the AJAX callback function
/// </summary>
[ScriptService]
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public partial class AjaxGrid : System.Web.Services.WebService 
{
    // private method to read profile from session data
    // the session may expire, if so normally requires recreation of session data
    // (perhaps redirect to a login page).
    private GridProfileData Profile(int gridId)
    { return ((List<GridProfileData>)Session["GridProfile"])[gridId]; }

    // AJAX methods called from javascript
    // -----------------------------------
    [WebMethod(EnableSession = true)]
    [ScriptMethod]
    public AjaxResponse OnSort(int gridId, int col)
    {
        GridProfileData profile = Profile(gridId);
        int sortcol = profile.currentSortCol;
        if (sortcol == col) // toggle sort direction if no column change
            profile.currentSortDirection = !profile.currentSortDirection;
        else
        {   // else set new sort column (ascending)
            profile.currentSortDirection = false;
            profile.currentSortCol = (byte)col;
        }
        return Repaint(profile, gridId);
    }

    [WebMethod(EnableSession = true)]
    [ScriptMethod]
    public AjaxResponse OnFilter(int gridId, int col, string value)
    {
        GridProfileData profile = Profile(gridId);
        profile.columns[col].currentFilter = (value.Length == 0 || value == NoFilterText) ? null : value;
        return RepaintData(profile, gridId);
    }

    [WebMethod(EnableSession = true)]
    [ScriptMethod]
    public AjaxResponse OnFreeTextFilter(int gridId, string value)
    {
        GridProfileData profile = Profile(gridId);
        profile.currentFreeTextFilter = value;
        return Repaint(profile, gridId);
    }

    [WebMethod(EnableSession = true)]
    [ScriptMethod]
    public void OnGridUpdate(int gridId, int id, int col, string value)
    {
        GridProfileData profile = Profile(gridId);
        UpdateCell(gridId, profile, id, col, value);
    }

    [WebMethod(EnableSession = true)]
    [ScriptMethod]
    public AjaxResponse OnNewRow(int gridId, bool newrow)
    {
        GridProfileData profile = Profile(gridId);
        profile.addingNewRow = newrow;
        return Repaint(profile, gridId);
    }


    [WebMethod(EnableSession = true)]
    [ScriptMethod]
    public AjaxResponse OnSaveNewRow(int gridId)
    {
        return InsertRow(gridId, Profile(gridId));
    }

    [WebMethod(EnableSession = true)]
    [ScriptMethod]
    public AjaxResponse OnUpdateNewRow(int gridId, int col, string value)
    {
        return UpdateNewRow(gridId, col, value, Profile(gridId));
    }

    [WebMethod(EnableSession = true)]
    [ScriptMethod]
    public AjaxResponse OnUpdateMaxResults(int gridId, int value)
    {
        GridProfileData profile = Profile(gridId);
        profile.currentTableMax = value;
        return RepaintData(profile, gridId);
    }

    // this method illustrates an interesting way of generating language-independent javascript on demand
    // just call the server, who knows who you are, and it will generate text for you
    [WebMethod(EnableSession = true)]
    [ScriptMethod]
    public string OnTools(int gridId)
    {
        GridProfileData profile = Profile(gridId);
        string maxresults = (profile.currentTableMax == 0) ? "" : profile.currentTableMax.ToString();
        StringBuilder html = new StringBuilder();
        html.AppendFormat (
            "<div class='popuptitlebar'>"
            + "<a onclick='return hidePopup(\"gridTools\");' href='#'><img src='img/cancel.gif' width='19' height='20' /></a>"
            + "</div>"
            + "<div class='popupcontents'>"
            + "<span>Limiting the results displayed in the table can improve the response time. If the results exceed the limit specified below, only that number will be displayed and the settings indicator will highlight to notify you to apply a sort or filter</span><br /><br />"
            + "<span style='margin:4px'>max to display</span><input type='text' id='txtMax' value='{1}'/><br /><br />"
            + "<div align='right'><button title='Output CSV' style='width:80px;margin-right:5px;' onclick='return exportTable(\"{0}\");'>Output CSV</button>"
            + "<button title='Update max results' style='width:60px;margin-right:5px;' onclick='return updatePopupMax(\"{0}\");'>Ok</button>"
            + "<button title='No maximum' style='width:60px;margin-right:5px;' onclick='return noPopupMax(\"{0}\");'>No max</button>"
            + "<button title='Cancel' style='width:60px;' onclick='return hidePopup(\"gridTools\");'>Cancel</button>"
            + "</div>", gridId,maxresults);
        return html.ToString();
    }

}