datagrid
using System;
using System.Web.UI.WebControls;
using System.Data;
/*
* The Control assumes the following:
*
* 1) It is bound to a DataView object.
* 2) The app will use direct SQL commands to update the source (NO batch update).
* 3) No custom paging is enabled.
*
* If you plan to support sorting, then some aspects of this code should be reviewed
* and adapted.
*
*/
namespace BWSLib
{
namespace Controls
{
public class EditableGrid : DataGrid
{
// Constructor that sets some styles and graphical properties
public EditableGrid()
{
AllowFullEditing = true;
AddNewRow = false;
RejectChanges = false;
MustInsertRow = false;
AllowPaging = true;
// Handlers
Init += new EventHandler(OnInit);
PageIndexChanged += new DataGridPageChangedEventHandler(OnPageIndexChanged);
ItemCreated += new DataGridItemEventHandler(OnItemCreated);
CancelCommand += new DataGridCommandEventHandler(OnCancelCommand);
EditCommand += new DataGridCommandEventHandler(OnEditCommand);
UpdateCommand += new DataGridCommandEventHandler(OnUpdateCommand);
DeleteCommand += new DataGridCommandEventHandler(OnDeleteCommand);
}
// PROPERTY: AllowFullEditing
// Enable full editing
public bool AllowFullEditing;
// PROPERTY: AddNewRow
// if true must add an empty row at the bottom of the data source
public bool AddNewRow;
// INTERNAL PROPERTY: RejectChanges
// if true must reject changes on the last row of the data source
protected bool RejectChanges;
// INTERNAL PROPERTY: MustInsertRow
// if true must INSERT instead of UPDATE and there's a pending change
protected bool MustInsertRow
{
get {return Convert.ToBoolean(ViewState["MustInsertRow"]);}
set {ViewState["MustInsertRow"] = value;}
}
// PROPERTY: DataSource (override)
public override object DataSource
{
get {return base.DataSource;}
set
{
base.DataSource = value;
if (AllowFullEditing)
{
if (AddNewRow)
{
AddNewRow = false;
InsertNewRow();
}
if (AllowFullEditing && RejectChanges)
{
RejectChanges = false;
MustInsertRow = false;
RejectChangesOnLastRow();
}
}
}
}
// PROPERTY: command columns
public bool ShowWebdings = false;
public String EditColumnText = "Edit";
public String EditColumnUpdateText = "OK";
public String EditColumnCancelText = "Cancel";
public String DeleteColumnText = "Delete";
// EVENT: InitRow
public delegate void DataGridInitRowEventHandler(Object sender, DataGridInitRowEventArgs e);
public event DataGridInitRowEventHandler InitRow;
private void OnInitRow(DataGridInitRowEventArgs e)
{
if (InitRow != null)
InitRow(this, e);
}
// EVENT: UpdateView
public event EventHandler UpdateView;
protected virtual void OnUpdateView(EventArgs e)
{
if (UpdateView != null)
UpdateView(this, e);
}
// EVENT: SaveData
public event DataGridCommandEventHandler SaveData;
protected virtual void OnSaveData(DataGridCommandEventArgs e)
{
if (SaveData != null)
SaveData(this, e);
}
// EVENT: InsertData
public event DataGridCommandEventHandler InsertData;
protected virtual void OnInsertData(DataGridCommandEventArgs e)
{
if (InsertData != null)
InsertData(this, e);
}
// EVENT: DeleteData
public event DataGridCommandEventHandler DeleteData;
protected virtual void OnDeleteData(DataGridCommandEventArgs e)
{
if (DeleteData != null)
DeleteData(this, e);
}
// EVENT HANDLER: Init
public void OnInit(Object sender, EventArgs e)
{
if (AllowFullEditing)
AddWorkerColumns();
}
// EVENT HANDLER: ItemCreated
public void OnItemCreated(Object sender, DataGridItemEventArgs e)
{
ListItemType lit = e.Item.ItemType;
if (lit == ListItemType.Item || lit == ListItemType.AlternatingItem)
CustomizeItem(e);
}
// EVENT HANDLER: CancelCommand
public void OnCancelCommand(Object sender, DataGridCommandEventArgs e)
{
if (e.Item.ItemIndex == 0)
CurrentPageIndex = (CurrentPageIndex==0 ?0 :CurrentPageIndex-1);
// Clears edit mode
EditItemIndex = -1;
// Reject changes on the last row
RejectChanges = true;
// Show/Hide DELETE column
ToggleDeleteColumn(true);
// Refresh view
OnUpdateView(EventArgs.Empty);
}
// EVENT HANDLER: EditCommand
public void OnEditCommand(Object sender, DataGridCommandEventArgs e)
{
// Reject changes on the last row (if any)
RejectChanges = true;
// Show/Hide DELETE column
ToggleDeleteColumn(false);
// Enable editing on the clicked row
EditItemIndex = e.Item.ItemIndex;
// Refresh view
OnUpdateView(EventArgs.Empty);
}
// EVENT HANDLER: UpdateCommand
public void OnUpdateCommand(Object sender, DataGridCommandEventArgs e)
{
// Clear edit mode
EditItemIndex = -1;
// Show/Hide DELETE column
ToggleDeleteColumn(true);
// Reject changes on the last row
RejectChanges = true;
// Update or insert data
if (MustInsertRow)
OnInsertData(e);
else
OnSaveData(e);
// Refresh view
OnUpdateView(EventArgs.Empty);
}
// EVENT HANDLER: DeleteCommand
public void OnDeleteCommand(Object sender, DataGridCommandEventArgs e)
{
// Clear edit mode
EditItemIndex = -1;
// Delete data
OnDeleteData(e);
// First item in the row, one page back
if (Items.Count == 1)
CurrentPageIndex = (CurrentPageIndex==0 ?0 :CurrentPageIndex-1);
// Refresh view
OnUpdateView(EventArgs.Empty);
}
// EVENT HANDLER: PageIndexChanged
public void OnPageIndexChanged(Object sender, DataGridPageChangedEventArgs e)
{
// Clears edit mode
EditItemIndex = -1;
// Reject changes on the last row
RejectChanges = true;
// Show/Hide DELETE column
ToggleDeleteColumn(true);
// Set the new page index
CurrentPageIndex = e.NewPageIndex;
// Refresh data
OnUpdateView(EventArgs.Empty);
}
/* ---------------------------------------------------------------------*/
/* ------------------------ INTERNALS ---------------------------------*/
/* ---------------------------------------------------------------------*/
// Reject changes on the last row
private void RejectChangesOnLastRow()
{
// Get the underlying DataTable object
DataTable dt = ((DataView) DataSource).Table;
DataRow drLast = dt.Rows[dt.Rows.Count-1];
if (drLast.RowState == DataRowState.Added)
drLast.RejectChanges();
}
// Show/Hide the DELETE column when in edit mode
private void ToggleDeleteColumn(bool bViewState)
{
int nGridColCount = Columns.Count;
Columns[nGridColCount-1].Visible = bViewState;
}
// Put the grid in edit mode by adding a blank row
private void InsertNewRow()
{
// Show/Hide DELETE column
ToggleDeleteColumn(false);
// Get the underlying DataTable object
DataTable dt = ((DataView) DataSource).Table;
// If any pending changes, stop here...
DataTable tmpTableOfPendingChanges = dt.GetChanges(DataRowState.Added);
if (tmpTableOfPendingChanges != null)
return;
// Add the new row
DataRow row = dt.NewRow();
dt.Rows.Add(row);
// Initialize the row
DataGridInitRowEventArgs dgire = new DataGridInitRowEventArgs();
dgire.Row = row;
OnInitRow(dgire);
// Goto to last page (return last index in the page)
int nNewItemIndex = SetIndexesToLastPage(dt);
// Turn edit mode on for the newly added row
EditItemIndex = nNewItemIndex;
// Tracks that a new row has just been added
MustInsertRow = true;
}
// Update indexes to point to last page
private int SetIndexesToLastPage(DataTable dt)
{
int nRemainder = (dt.Rows.Count % PageSize);
int nNewItemIndex = nRemainder;
CurrentPageIndex = (dt.Rows.Count / PageSize)-1; // 0-based
if (CurrentPageIndex <0)
CurrentPageIndex = 0;
if (nNewItemIndex >0)
CurrentPageIndex ++;
if (nNewItemIndex == 0)
nNewItemIndex = PageSize-1;
else
nNewItemIndex--;
return nNewItemIndex;
}
// Add Edit and Delete columns
private void AddWorkerColumns()
{
if (ShowWebdings)
{
EditColumnText = "/";
EditColumnUpdateText = "R";
EditColumnCancelText = "T";
DeleteColumnText = "r";
}
// Edit column
EditCommandColumn editColumn = new EditCommandColumn();
editColumn.EditText = EditColumnText;
editColumn.UpdateText = EditColumnUpdateText;
editColumn.CancelText = EditColumnCancelText;
if (ShowWebdings)
{
editColumn.ItemStyle.Font.Size = 11;
editColumn.ItemStyle.Font.Name = "wingdings 2";
}
Columns.Add(editColumn);
// Delete column
ButtonColumn deleteColumn = new ButtonColumn();
deleteColumn.CommandName = "delete";
deleteColumn.Text = DeleteColumnText;
if (ShowWebdings)
deleteColumn.ItemStyle.Font.Name = "webdings";
Columns.Add(deleteColumn);
}
// Customize items in the grid
private void CustomizeItem(DataGridItemEventArgs e)
{
WebControl wc;
// Adds a tooltip to Edit
wc = ((WebControl) e.Item.Cells[Columns.Count-2]);
wc.ToolTip = "Edit this row";
// Adds a client-side onclick handler and a tooltip to Delete
wc = ((WebControl) e.Item.Cells[Columns.Count-1]);
String js = "return confirm('Do you really want to delete this row?');";
wc.Attributes["onclick"] = js;
wc.ToolTip = "Delete this row";
}
}
public sealed class DataGridInitRowEventArgs : EventArgs
{
public DataRow Row;
}
}
}