categories.aspx.cs

wrox c#高级编程

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using Wrox.WebModules.Accounts.Business;

namespace Wrox.WebModules.NewsManager.Web
{
	/// <summary>
	/// Summary description for Categories.
	/// </summary>
	public class Categories : Wrox.ThePhile.Web.PhilePage
	{
		protected System.Web.UI.WebControls.LinkButton AddNew;
		protected System.Web.UI.WebControls.LinkButton CancelAddNew;
		protected System.Web.UI.WebControls.DataGrid CatGrid;
		protected System.Web.UI.WebControls.Table TableNewCategory;
		protected System.Web.UI.WebControls.RequiredFieldValidator ValidateEditName;
		protected System.Web.UI.WebControls.RequiredFieldValidator ValidateNewName;
		protected System.Web.UI.WebControls.TextBox EditCatName;
		protected System.Web.UI.WebControls.TextBox EditCatDescr;
		protected System.Web.UI.WebControls.TextBox EditCatImageUrl;
		protected System.Web.UI.WebControls.TextBox NewCatName;
		protected System.Web.UI.WebControls.TextBox NewCatDescr;
		protected System.Web.UI.WebControls.TextBox NewCatImageUrl;
		protected System.Web.UI.WebControls.Button Create;
		protected System.Web.UI.WebControls.TableRow AddNewControlsRow;
		protected System.Web.UI.WebControls.TableRow CreateNewRow;
		protected System.Web.UI.WebControls.Label AddNewError;
      
		protected void Page_Load(object sender, EventArgs e)
		{
			// check if the current user is allowed to administer the news
			if (!Context.User.Identity.IsAuthenticated || 
				!((PhilePrincipal)Context.User).HasPermission((int)NewsManagerPermissions.AdministerNews))
			{
				// if not, redirect to the Login page
				Response.Redirect("/ThePhile/Modules/Users/Login.aspx?ShowError=true", true);
			}

			if (!Page.IsPostBack)
			{
				// bind the page's controls
				BindGrid();
			}
		}

		protected void BindGrid() 
		{
			// get all the categories
			DataView myDV = Business.Category.GetCategories().Tables[0].DefaultView;
			
			// sort the data according to the SortExpression value
			if (CatGrid.Attributes["SortExpression"] != null)
				myDV.Sort = CatGrid.Attributes["SortExpression"];

			CatGrid.DataSource = myDV;
			CatGrid.DataBind();
		}

		protected void CatGrid_Sort(Object sender, DataGridSortCommandEventArgs e) 
		{
			AddNewError.Visible = false;
			ShowAddNewControls(false);
			CatGrid.EditItemIndex = -1;
			// set the SortExpression attribute that will be used to actually sort
			// the data in the BindGrid method
			CatGrid.Attributes["SortExpression"] = e.SortExpression.ToString();
			BindGrid();
		}


		protected void CatGrid_Edit(object sender, DataGridCommandEventArgs e)
		{
			AddNewError.Visible = false;
			ShowAddNewControls(false);
			// start editing
			CatGrid.EditItemIndex = (int)e.Item.ItemIndex;
			BindGrid();
		}

		protected void CatGrid_CancelEdit(object sender, DataGridCommandEventArgs e)
		{
			CatGrid.EditItemIndex = -1;
			BindGrid();
		}

		protected void CatGrid_Update(object sender, DataGridCommandEventArgs e)
		{
			if (Page.IsValid)
			{
				// get the new values from the textboxes
				string catName = ((TextBox)e.Item.FindControl("EditCatName")).Text;
				string catDescr = ((TextBox)e.Item.FindControl("EditCatDescr")).Text;
				string catImageUrl = ((TextBox)e.Item.FindControl("EditCatImageUrl")).Text;
				int categoryID = (int)CatGrid.DataKeys[e.Item.ItemIndex];

				// update the values
				Business.Category category = new Business.Category(categoryID);
				category.Name = catName;
				category.Description = catDescr;
				category.ImageUrl = catImageUrl;
				category.Update();
				
				CatGrid.EditItemIndex = -1;	
				BindGrid();
			}
		}

		protected void CatGrid_Delete(object sender, DataGridCommandEventArgs e)
		{
			AddNewError.Visible = false;
			ShowAddNewControls(false);
			CatGrid.EditItemIndex = -1;
			// get the ID of this record and delete it
			Business.Category category = new Business.Category((int)CatGrid.DataKeys[e.Item.ItemIndex]);
			category.Delete();
			// re-bind
			BindGrid();
		}

		protected void AddNew_Click(object sender, EventArgs e)
		{
			if (Page.IsValid)
			{
				Business.Category category = new Business.Category();
				// add the new record
				if (category.Create(NewCatName.Text, NewCatDescr.Text, NewCatImageUrl.Text) < 0)
				{
					// if Add returned -1, the category was already present
					AddNewError.Visible = true;	
				}
				ShowAddNewControls(false);
				BindGrid();
			}
		}
		
		protected void CancelAddNew_Click(object sender, EventArgs e)
		{
			ShowAddNewControls(false);
		}

		protected void Create_Click(object sender, EventArgs e)
		{
			// show the textboxes and buttons for adding a new record
			AddNewError.Visible = false;
			ShowAddNewControls(true);
			CatGrid.EditItemIndex = -1;
			BindGrid();
		}
		
		protected void ShowAddNewControls(bool ShowControls)
		{
			// show/hide the controls for adding a new record
			NewCatName.Text="";
			NewCatDescr.Text="";
			NewCatImageUrl.Text="";

			AddNewControlsRow.Visible = ShowControls;
			CreateNewRow.Visible = !ShowControls;
		}

		public string GetImage(object imageUrl)
		{
			if (imageUrl.ToString().Length > 0)
				return "<img border=\"0\" src=\"" + imageUrl.ToString() + "\">";
			else
				return "";
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: This call is required by the ASP.NET Web Form Designer.
			//
			base.OnInit(e);
			InitializeComponent();
			
		}
		
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{    
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion
	}
}