GridView editing e sorting

C#: Default.aspx.csCopia

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

public partial class _Default : System.Web.UI.Page
{

  protected void Page_Load(object sender, EventArgs e)
  {
    if (!Page.IsPostBack)
    {
      LoadDataSource();
      PnlNew.Visible = false;
    }

  }

  #region Manage DataSource

  //test data source
  private DataTable Table
  {
    get { return (DataTable)ViewState["tbl"]; }
    set { ViewState["tbl"] = value; }
  }

  private void LoadDataSource()
  {
    //bild example data source
    DataTable tbl = new DataTable();
    //add columns
    DataColumnCollection cols = tbl.Columns;
    cols.Add("ID", typeof(System.Int32));
    cols.Add("Code", typeof(System.String));
    cols.Add("Description", typeof(System.String));
    cols.Add("Modified", typeof(System.DateTime));
    //add rows
    DataRowCollection rows = tbl.Rows;
    rows.Add(new object[] { 2, "KJ7", "Piastra madre", DateTime.Now });
    rows.Add(new object[] { 17, "FH5", "Processore", DateTime.Now });
    rows.Add(new object[] { 4, "ER4", "Ram", DateTime.Now });
    rows.Add(new object[] { 33, "W34", "Rom", DateTime.Now });
    rows.Add(new object[] { 1, "SS2", "Hard Disk", DateTime.Now });
    rows.Add(new object[] { 7, "SD3", "Video", DateTime.Now });
    rows.Add(new object[] { 8, "TA9", "Tastiera", DateTime.Now });

    Table = tbl;
    Bind();
  }

  private void DataSourceUpdate(string code, string description)
  {
    DataSourceUpdate(0, code, description);
  }

  private void DataSourceUpdate(int id, string code, string description)
  {
    DataRow row;
    if (id != 0)
    {
      DataRow[] rows = Table.Select(string.Format("ID={0}", id));
      row = rows[0];
    }
    else
    {
      row = Table.NewRow();
      Table.Rows.Add(row);
      //get new id
      row["ID"] = GetNewID();
    }

    row["Code"] = code;
    row["Description"] = description;
    row["Modified"] = DateTime.Now;
    row.AcceptChanges();

  }

  private int GetNewID()
  {
    int id = 0;
    DataRow[] rows = Table.Select("ID > 0", "ID DESC");
    if (rows.Length > 0)
    {
      id = (int)rows[0]["ID"];
    }
    return id + 1;
  }

  private void DataSourceDelete(int id)
  {
    DataRow[] rows = Table.Select(string.Format("ID={0}", id));
    DataRow row = rows[0];
    row.Delete();
  }

  #endregion

  #region GridView

  private void Bind()
  {
    GridView1.DataSource = Table;
    GridView1.DataBind();
  }

  #region Editing

  protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
  {
    GridView gv = (GridView)sender;
    int id = (int)gv.DataKeys[e.RowIndex].Value;
    DataSourceDelete(id);
    Bind();
  }

  protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
  {
    //start editing row
    GridView gv = (GridView)sender;
    gv.EditIndex = e.NewEditIndex;
    Bind();
  }

  protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
  {
    //update editing value
    GridView gv = (GridView)sender;
    //get id - row key
    int id = (int)gv.DataKeys[e.RowIndex].Value;
    GridViewRow gRow = gv.Rows[e.RowIndex];
    string code = ((TextBox)(gRow.Cells[0].Controls[0])).Text;
    string description = ((TextBox)(gRow.Cells[1].Controls[0])).Text;
    //write update to datasource
    DataSourceUpdate(id, code, description);
    //show data
    gv.EditIndex = -1;
    Bind();
  }

  protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
  {
    //cancel editing without saving
    GridView gv = (GridView)sender;
    gv.EditIndex = -1;
    Bind();
  }

  #endregion

  #region New

  protected void BtnNew_Click(object sender, EventArgs e)
  {
    TxtCode.Text = "";
    TxtDescription.Text = "";
    PnlNew.Visible = true;
    BtnNew.Enabled = false;
  }

  protected void BtnNewSave_Click(object sender, EventArgs e)
  {
    string code = TxtCode.Text;
    string description = TxtDescription.Text;
    DataSourceUpdate(code, description);
    Bind();

    PnlNew.Visible = false;
    BtnNew.Enabled = true;
  }

  protected void BtnNewCancel_Click(object sender, EventArgs e)
  {
    PnlNew.Visible = false;
    BtnNew.Enabled = true;
  }
  #endregion

  #region Sorting

  protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
  {
    if (string.IsNullOrEmpty(e.SortExpression) == false)
    {
      if (GvSortDirection == SortDirection.Ascending)
        GvSortDirection = SortDirection.Descending;
      else
        GvSortDirection = SortDirection.Ascending;

      GridView gv = (GridView)sender;
      SortGridView(gv, e.SortExpression, GvSortDirection);
    }
  }

  //memory sorting direction
  private SortDirection GvSortDirection
  {
    get
    {
      if (ViewState["SD"] == null)
        ViewState["SD"] = SortDirection.Descending;
      return (SortDirection)ViewState["SD"];
    }
    set { ViewState["SD"] = value; }
  }

  private void SortGridView(GridView gv, string sortExpression, SortDirection direction)
  {
    DataView dv = new DataView(Table);
    dv.Sort = sortExpression + (direction == SortDirection.Ascending ? " ASC" : " DESC");
    gv.DataSource = dv;
    gv.DataBind();
  }

  #endregion

  #endregion

  #region Button

  protected void BtnReload_Click(object sender, EventArgs e)
  {
    LoadDataSource();
  }

  protected void BtnRefresh_Click(object sender, EventArgs e)
  {
    Bind();
  }
  #endregion

}