options.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.Polls.Web
{
	/// <summary>
	/// Summary description for Options.
	/// </summary>
	public class Options : Wrox.ThePhile.Web.PhilePage
	{
		protected System.Web.UI.WebControls.DropDownList QuestionsDropDown;
		protected System.Web.UI.WebControls.DataGrid OptionsGrid;
		protected System.Web.UI.WebControls.LinkButton AddNew;
		protected System.Web.UI.WebControls.LinkButton CancelAddNew;
		protected System.Web.UI.WebControls.HyperLink AddCancel;
		protected System.Web.UI.WebControls.TextBox NewOptionText;
		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.TableCell AddNewResultCell;
		protected System.Web.UI.WebControls.Table Table1;
		protected System.Web.UI.WebControls.Table TableOptions;
		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 polls
			if (!Context.User.Identity.IsAuthenticated || 
				!((PhilePrincipal)Context.User).HasPermission((int)PollsPermissions.AdministerPolls))
			{
				// if not, redirect to the Login page
				Response.Redirect("/ThePhile/Modules/Users/Login.aspx?ShowError=true", true);
			}

			// get the QuestionID from the QueryString
			string questionID = Request.Params["QuestionID"];
			OptionsGrid.Attributes["QuestionID"] = questionID;
			
			if (!Page.IsPostBack)
			{
				// load all the avaible questions in the DropDown control
				DataView myDV = Business.Question.GetQuestions().Tables[0].DefaultView;
				QuestionsDropDown.DataSource = myDV;
				QuestionsDropDown.DataBind();

				if (questionID!=null)
				{
					// select the DropDown element according to the questionID
					QuestionsDropDown.SelectedIndex = QuestionsDropDown.Items.IndexOf(
						QuestionsDropDown.Items.FindByValue(questionID));
				}
				
				// (re)bind the page's controls
				BindGrid();
			}
		}

		protected void BindGrid() 
		{
			int questionID;

			// get the QuestionID value from the Grid's attributes
			if ( OptionsGrid.Attributes["QuestionID"] != null )
				questionID = int.Parse(OptionsGrid.Attributes["QuestionID"]);
			else
				questionID = int.Parse(QuestionsDropDown.SelectedItem.Value);

			// get all the options of this question
			DataView myDV = new Business.Question(questionID).GetOptions().Tables[0].DefaultView;

			// sort the records according to the SortExpression value in the Grid's attributes
			if ( OptionsGrid.Attributes["SortExpression"]!="" )
				myDV.Sort = OptionsGrid.Attributes["SortExpression"];

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

		protected void QuestionsDropDown_IndexChanged(object sender, EventArgs e)
		{
			// reload the page to show the options for the selected question
			// This will also hide the controls to add a option if they were visible
			Response.Redirect("Options.aspx?QuestionID=" + QuestionsDropDown.SelectedItem.Value);
		}
		
		protected void OptionsGrid_Sort(Object sender, DataGridSortCommandEventArgs e) 
		{
			AddNewError.Visible = false;
			ShowAddNewControls(false);
			OptionsGrid.EditItemIndex = -1;
			// set the SortExpression attribute that will be used to actually sort
			// the data in the BindGrid method
			OptionsGrid.Attributes["SortExpression"] = e.SortExpression.ToString();
			BindGrid();
		}

		protected void OptionsGrid_Edit(object sender, DataGridCommandEventArgs e)
		{
			AddNewError.Visible = false;
			ShowAddNewControls(false);
			// start the editing for this item
			OptionsGrid.EditItemIndex = (int)e.Item.ItemIndex;
			BindGrid();
		}

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

		protected void OptionsGrid_Update(object sender, DataGridCommandEventArgs e)
		{
			if (Page.IsValid)
			{
				int optionID = (int)OptionsGrid.DataKeys[e.Item.ItemIndex];
				string optionText = ((TextBox)e.Item.FindControl("EditOptionText")).Text;

				// update the option
				Business.Option option = new Business.Option(optionID);
				option.Text = optionText;
				option.Update();

				OptionsGrid.EditItemIndex = -1;	
				BindGrid();
			}
		}

		protected void OptionsGrid_Delete(object sender, DataGridCommandEventArgs e)
		{		
			AddNewError.Visible = false;
			ShowAddNewControls(false);
			OptionsGrid.EditItemIndex = -1;
			// delete this option
			Business.Option option = new Business.Option((int)OptionsGrid.DataKeys[e.Item.ItemIndex]);
			option.Delete();
			BindGrid();
		}

		protected void AddNew_Click(object sender, EventArgs e)
		{
			if (Page.IsValid)
			{
				int questionID = int.Parse(QuestionsDropDown.SelectedItem.Value);
				string optionText = NewOptionText.Text;

				// add the new option
				if (new Business.Question(questionID).AddOption(optionText).ID < 0)
				{
					// if the call to the Add method returned -1, it means that this option
					// was already present, so show the label that tells this
					AddNewError.Visible = true;	
				}

				// hide the controls for adding an option
				ShowAddNewControls(false);
				BindGrid();
			}
		}
		
		protected void CancelAddNew_Click(object sender, EventArgs e)
		{
			ShowAddNewControls(false);
		}

		protected void Create_Click(object sender, EventArgs e)
		{
			// show the controls for adding a new option
			AddNewError.Visible = false;
			ShowAddNewControls(true);
			OptionsGrid.EditItemIndex = -1;
			BindGrid();
		}
		
		protected void ShowAddNewControls(bool ShowControls)
		{
			// show or hide the controls for adding a new option
			NewOptionText.Text = "";

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