newshistory.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.MailingLists.Web
{
	public class NewsHistory : Wrox.ThePhile.Web.PhilePage
	{
		protected System.Web.UI.WebControls.Label MsgPreview;
		protected System.Web.UI.WebControls.DataGrid NewsGrid;
		protected System.Web.UI.WebControls.Table TableLists;
		protected System.Web.UI.WebControls.DropDownList ListsDropDown;
	
		protected void Page_Load(object sender, EventArgs e)
		{
			// check if the current user is allowed to administer lists/subscriptions
			if (!Context.User.Identity.IsAuthenticated || 
				!((SitePrincipal)Context.User).HasPermission((int)MailingListsPermissions.AdministerData))
			{
				// if not, redirect to the Login page
				Response.Redirect("/ThePhile/Modules/Users/Login.aspx?ShowError=true", true);
			}

			// get the ListID param from QueryString
			string listID = Request.Params["ListID"];
			NewsGrid.Attributes["ListID"] = listID;
		
			if (!Page.IsPostBack)
			{
				// fill the DropDown control with the avaible lists
				ListsDropDown.DataSource = Business.List.GetLists().Tables[0].DefaultView;
				ListsDropDown.DataBind();

				// select a DropDown item according to the ListID value specified in the QueryString
				if (listID!=null)
				{
					ListsDropDown.SelectedIndex = ListsDropDown.Items.IndexOf(
						ListsDropDown.Items.FindByValue(listID));
				}
			}

			// (re)bind the page's controls
			BindGrid();
		}

		protected void BindGrid() 
		{
			int listID;

			// get the ListID from the DataGrid's attribute
			if ( NewsGrid.Attributes["ListID"] != null )
				listID = int.Parse(NewsGrid.Attributes["ListID"]);
			else
				listID = int.Parse(ListsDropDown.SelectedItem.Value);

			// get all the subscribers of that list
			Business.List list = new Business.List(listID);
			DataView myDV = list.GetNewsletters().Tables[0].DefaultView;
			
			// sort the subscribers according to the specified DataGrid's attribute
			if ( NewsGrid.Attributes["SortExpression"]!="" )
				myDV.Sort = NewsGrid.Attributes["SortExpression"];

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

		protected void ListsDropDown_IndexChanged(object sender, EventArgs e)
		{
			Response.Redirect("NewsHistory.aspx?ListID=" + ListsDropDown.SelectedItem.Value);
		}
		
		protected void NewsGrid_PageChanged(Object sender, DataGridPageChangedEventArgs e)
		{
			UnselectGridItem();
			// change the current page
			NewsGrid.CurrentPageIndex = e.NewPageIndex;
			BindGrid();	
		}
		
		protected void NewsGrid_Sort(Object sender, DataGridSortCommandEventArgs e) 
		{
			UnselectGridItem();
			// set the SortExpression attribute that will be used to actually sort
			// the data in the BindGrid method
			NewsGrid.Attributes["SortExpression"] = e.SortExpression.ToString();
			BindGrid();
		}

		protected void NewsGrid_Delete(object sender, DataGridCommandEventArgs e)
		{
			UnselectGridItem();
			// delete the news identified by the ID of this row
			Business.Newsletter newsletter = new Business.Newsletter((int)NewsGrid.DataKeys[e.Item.ItemIndex]);
			newsletter.Delete();
			BindGrid();
		}

		protected void NewsGrid_SelectionChanged(object sender, EventArgs e)
		{
			// get the ID of the selected row and the respective Newsletter object
			int newsID = int.Parse(NewsGrid.DataKeys[NewsGrid.SelectedIndex].ToString());
			Business.Newsletter newsletter = new Business.Newsletter(newsID);
			// get the Body of the news from the DB
			string body = newsletter.Body;
			// if the news format was not HTML, encode the Body text
			if (!newsletter.IsHTML)
			{
				body = HttpUtility.HtmlEncode(body);
				// replace the new lines with <br>, to show the new lines in the Label
				body = body.Replace("\n", "<br>");
				body = body.Replace("\r", "");
			}

			// show the Body text in the Preview label
			MsgPreview.Text = body;
			MsgPreview.Visible = true;
		}
		
		protected void UnselectGridItem()
		{
			// hide the Preview control and unselect the selected row
			NewsGrid.SelectedIndex = -1;
			MsgPreview.Text = "";
			MsgPreview.Visible = false;
		}
		
		
		#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
	}
}