using System;
using System.Collections.Generic;
using System.Data;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
 private DataSet ds = new DataSet(); 

 protected void Page_Load(object sender, EventArgs e)
 {
   ds.ReadXml(AppDomain.CurrentDomain.BaseDirectory + "\\Anagrafica.xml");
   if(!IsPostBack)
   {
     GridView1.DataSource = ds;
     GridView1.DataBind();
   }
 }

 protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
 {
  if (ViewState["SortExpression"] != null)
  {  
   String sortDirection = Convert.ToString(ViewState["SortDirection"]);
   String sortExpression = Convert.ToString(ViewState["SortExpression"]); 
   if (sortExpression == e.SortExpression)
   {
    ViewState["SortDirection"] = ChangeDirection(sortDirection);
   }
   else
   {
    ViewState["SortExpression"] = e.SortExpression;
    ViewState["SortDirection"] = "ASC";
   }
  }
  else
  {
   ViewState["SortExpression"] = e.SortExpression;
   ViewState["SortDirection"] = "ASC";
  }
  DataView dv = ds.Tables[0].DefaultView;
  String SortExpDirection = Convert.ToString(ViewState["SortExpression"]);
  SortExpDirection += " " + ViewState["SortDirection"];
  dv.Sort = SortExpDirection;
  GridView1.DataSource = dv;
  GridView1.DataBind();
 }
 
 private String ChangeDirection(String oldDirection)
 {
   String newDirection = "";
   switch (oldDirection)
   {
     case "ASC":
       newDirection = "DESC";
       break;
     default:
       newDirection = "ASC";
       break;
   }
   return newDirection;
 }
 
 protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)
 {
  if (e.Row.RowType == DataControlRowType.Header)
  {
   string NomeColonna;
   int numCell;
   numCell = e.Row.Cells.Count;
   
   for (int i = 0; i < numCell; i++)
   {
    // Recupero il controllo che sta nella cella dell'header
    //che è un LinkButton
    LinkButton LinkButtonOrdinamento = (LinkButton)e.Row.Cells[i].Controls[0];
    NomeColonna = LinkButtonOrdinamento.Text;
       
    //Creo il controllo ImageButton
    ImageButton ImageButtonOrdinamento = new ImageButton();
    ImageButtonOrdinamento.CommandName = LinkButtonOrdinamento.CommandName;
    string commandArgument = LinkButtonOrdinamento.CommandArgument;
    ImageButtonOrdinamento.CommandArgument = commandArgument;
    ImageButtonOrdinamento.ToolTip = "Ordina per " + NomeColonna;
    ImageButtonOrdinamento.Width = (Unit)10;
    
    //stabilisco l'immagine da visualizzare
    ImageButtonOrdinamento.ImageUrl = "frsun.gif";
    if (ViewState["SortExpression"] != null)
    {
     String sortExpression = Convert.ToString(ViewState["SortExpression"]);
     if (LinkButtonOrdinamento.CommandArgument == sortExpression)
     {
       if (Convert.ToString(ViewState["SortDirection"]) == "DESC")
       {
         ImageButtonOrdinamento.ImageUrl = "frgiu.gif";
       }
       else
       {
         ImageButtonOrdinamento.ImageUrl = "frsu.gif";
       }
     }
    }
       
    //Creo il controllo Label
    Label labelNomeColonna = new Label();
    labelNomeColonna.Text = NomeColonna + " ";
    Table tableOrd = new Table();
    TableRow tableRowOrd = new TableRow();
    TableCell tableCell0 = new TableCell();
    tableCell0.Controls.Add(labelNomeColonna);
    tableRowOrd.Cells.Add(tableCell0);
    TableCell tableCell1 = new TableCell();
    tableCell1.Controls.Add(ImageButtonOrdinamento);
    tableRowOrd.Cells.Add(tableCell1);
    tableOrd.Rows.Add(tableRowOrd);
      
    //cancello il controllo linkbutton dalla cella
    e.Row.Cells[i].Controls.Remove(LinkButtonOrdinamento);
      
    //Aggiungo il nuovo controllo
    e.Row.Cells[i].Controls.Add(tableOrd);
   }
  }
 }
}