Custom editable Datagrid with paging and sorting

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Introduction

This article shows you how to create a custom DataGrid with paging, alternate sorting, and is also completely editable

Details

When I was developing some asp.net pages, I lost a lot of time with Datagrids. The code here is to made that work more simple. Only drag the control to the page, complete some properties, point to the methods that controls the updating, deleting and you have a complete editable grid.

[ToolboxData("<{0}:editableElphGrid runat="\""server\">
    </{0}:editableElphGrid>")]
//ParseChildren allow to work with templates inside the custom datagrid
[ParseChildren(true)]
public class editableElphGrid : System.Web.UI.WebControls.DataGrid
{
    /// <summary>
    /// Points to the method that returns a datatable with data
    /// Apunta a la funcion q devolvera un dataTable con los datos
    /// </summary>
    public delegate DataTable getData();
    /// <summary>
    /// Obtain data event 
    /// Evento de obtener datos
    /// </summary>
    public event getData GetData;
    /// <summary>
    /// Points to method(to update data)
    /// Apunta a un metodo q nos servira para modificar datos
    /// </summary>
    public delegate void updateData(int dataKey,DataGridCommandEventArgs e);
    /// <summary>
    /// Update data event
    /// </summary>
    public event updateData UpdateData;
    /// <summary>
    /// Points to method(delete data)
    /// Apunta al metodo q usaremos para eliminar los datos
    /// </summary>
    public delegate void deleteData(int dataKey,DataGridCommandEventArgs e);
    /// <summary>
    /// delete data event
    /// </summary>
    public event deleteData DeleteData; 
    /// <summary>
    /// Cancel data
    /// </summary>
    public delegate void cancelData(int dataKey,DataGridCommandEventArgs e);
    /// <summary>
    /// cancel data event
    /// </summary>
    public event cancelData CancelData;
    /// <summary>
    /// edit data
    /// </summary>
    public delegate void editData(int dataKey,DataGridCommandEventArgs e);
    /// <summary>
    /// edit data event
    /// </summary>
    public event editData EditData;
    // Note: the params passed on the delegates
    // dataKey: is the DataKey field of the edited/
    // canceled/updated/deleted row
    // e: for work with the cells of the grid
    /// <summary>
    /// First sorting field
    /// campo por el q se ordenara en la primera carga
    /// </summary>
    private string _cFirst="";
    /// <summary>
    /// First sorting field
    /// campo por el q se ordenara en la primera carga
    /// </summary>
    public string FirstSortingField
    {
        get
        {return _cFirst;}
        set
        {_cFirst=value;}
    }
    // Inicializamos el grid
    protected override void OnInit(EventArgs e)
    {
        //paginacion=true
        this.AllowPaging=true;
        //ordenacion=true
        this.AllowSorting=true;
        //evento cambio de pagina
        //ADD the events
        this.PageIndexChanged+=new DataGridPageChangedEventHandler(
              cPage_elphGrid);
        //evento ordenar
        this.SortCommand+=new DataGridSortCommandEventHandler(
               Order_elphGrid);
        //evento de cargar datos
        this.Load+=new EventHandler(elphGrid_Load);
        this.EditCommand+=new DataGridCommandEventHandler(Edit_elphGrid);
        this.CancelCommand+=new DataGridCommandEventHandler(Cancel_elphGrid);
        this.DeleteCommand+=new DataGridCommandEventHandler(Delete_elphGrid);
        this.UpdateCommand+=new DataGridCommandEventHandler(Update_elphGrid);
        //clear the columns
        //limpiamos las columnas
        this.Columns.Clear();
        //create the editComandColumn an deleteColumn
        //creamos las columnas de editar i eliminar
        EditCommandColumn col=new EditCommandColumn();
        col.ButtonType=ButtonColumnType.LinkButton;
        col.CancelText="Cancel";
        col.EditText="Edit";
        col.UpdateText="Update";
        this.Columns.Add(col);
        ButtonColumn delCol=new ButtonColumn();
        delCol.CommandName="Delete";
        delCol.ButtonType=ButtonColumnType.LinkButton;
        delCol.Text="Delete";
        this.Columns.Add(delCol);
    }
    private void elphGrid_Load(object sender, EventArgs e)
    {
        if(!this.Page.IsPostBack)
        {
            //changed Session object for Viewstate
            if(this.AllowSorting&&this._cFirst!="")
                this.ViewState.Add("_orderBy",this._cFirst);
            this.ViewState.Add("_orderType","ASC");
            this.DataSource = CreateDataSet();
            this.DataBind();
        }
    }
    private void cPage_elphGrid(object sender, 
             DataGridPageChangedEventArgs e)
    {
        //PAging
        this.CurrentPageIndex = e.NewPageIndex;
        this.DataSource = CreateDataSet();
        this.DataBind();
    }
    private ICollection CreateDataSet() 
    {
        //this.ObtenerDatos call a external function that return data
        DataTable dt=this.GetData();
        if(this.AllowSorting&&this.ViewState["_orderBy"]!=null)
        {
            //sort the grid
            if(this.ViewState["_orderType"].ToString() == "ASC")
                dt.DefaultView.Sort=(string)
                   this.ViewState["_orderBy"].ToString()+" ASC";
            else if(this.ViewState["_orderType"].ToString()=="DESC")
                dt.DefaultView.Sort=(string)this.ViewState["_orderBy"]+
                          " DESC";
        }
        return dt.DefaultView;
    }
    public void Order_elphGrid(object sender, DataGridSortCommandEventArgs e) 
    { 
        this.ViewState["_orderBy"]=(string)e.SortExpression;
        if(this.ViewState["_orderType"].ToString()=="ASC")
            this.ViewState["_orderType"]="DESC";
        else if(this.ViewState["_orderType"].ToString()=="DESC")
            this.ViewState["_orderType"]="ASC";
        this.DataSource = CreateDataSet();
        this.DataBind(); 
    }
    public void Edit_elphGrid(object sender, 
           System.Web.UI.WebControls.DataGridCommandEventArgs e)
    {
        int id=Convert.ToInt32(this.DataKeys[e.Item.ItemIndex]);
        this.EditData(id,e);
        this.EditItemIndex=e.Item.ItemIndex;
        this.DataSource = CreateDataSet();
        this.DataBind();
    }
    public void Delete_elphGrid(object sender, 
          System.Web.UI.WebControls.DataGridCommandEventArgs e)
    {
        int id=Convert.ToInt32(this.DataKeys[e.Item.ItemIndex]);
        this.DeleteData(id,e);
        this.EditItemIndex=-1;
        this.DataSource = CreateDataSet();
        this.DataBind();
    }
    public void Update_elphGrid(object sender, 
           System.Web.UI.WebControls.DataGridCommandEventArgs e) 
    {
        int id=Convert.ToInt32(this.DataKeys[e.Item.ItemIndex]);
        this.UpdateData(id,e);
        this.EditItemIndex=-1;
        this.DataSource = CreateDataSet();
        this.DataBind();
    }
    public void Cancel_elphGrid(object sender, 
            System.Web.UI.WebControls.DataGridCommandEventArgs e) 
    {
        int id=Convert.ToInt32(this.DataKeys[e.Item.ItemIndex]);
        this.CancelData(id,e);
        this.EditItemIndex=-1;
        this.DataSource = CreateDataSet();
        this.DataBind();
    }
}

Well, now add the control on a page, and then you must fill the fields .

DataKeyField: That is the key field of the table, the unique identifier of a row. I put because I use that on Database actions, like delete a specific row etc.

And on the tab of Events :- GetData, CancelData, EditData and DeleteData.

Finally you should have something like this.

On the aspx page:

<cc1:editableElphGrid id="EditableElphGrid1" runat="server" 
    DataKeyField="intId"></cc1:editableElphGrid>

On the code behind

protected elphControls.editableElphGrid EditableElphGrid1;
   
private void InitializeComponent()
{    
 this.EditableElphGrid1.DeleteData += 
   new elphControls.editableElphGrid.eliminarDatos(this.del);
 this.EditableElphGrid1.GetData += 
   new elphControls.editableElphGrid.obtenerDatos(this.obt);
this.EditableElphGrid1.EditData += 
   new elphControls.editableElphGrid.editarDatos(this.edit);
 this.EditableElphGrid1.UpdateData += 
   new elphControls.editableElphGrid.actualizarDatos(this.act);
 this.EditableElphGrid1.CancelData += 
   new elphControls.editableElphGrid.cancelarDatos(this.cncl);
 this.Load += new System.EventHandler(this.Page_Load);
}
private System.Data.DataTable obt()
{
OleDbConnection conn=new OleDbConnection(
    "Provider=Microsoft.Jet.OLEDB.4.0;Data source=E:\\bdProves.mdb");
 OleDbDataAdapter adapter=new OleDbDataAdapter("select * from tabla",conn);
 adapter.SelectCommand.CommandType=CommandType.Text;
 conn.Open();
 DataSet ds=new DataSet();
 adapter.Fill(ds,"aa");
 conn.Close();
 conn.Dispose();
 return ds.Tables["aa"];
}
private void edit(int dataKey, 
    System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
//here the logic asociated with edit comand... if you have
}
private void del(int dataKey, 
    System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
 //here the logic asociated with delete comand
}
private void cncl(int dataKey, 
    System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
 //here the logic asociated with Cancel comand
}
private void act(int dataKey, 
    System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
 //here the logic asociated with update comand
}

Update

Changed the session to save the sorting params for a viewstate, now you can have two grids on the same page. Also Changed the declaration of the first sorting field, now this isn't necessary. Thanks to Zanoza.

Conclusion

I think that this grid is a good base to customize a datagrid. Hope it could be useful. All comments about this are welcomed.