addtocart.aspx.cs

这是一个编好的网上书店系统

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;

namespace BookStore
{
	/// <summary>
	/// AddToCart 的摘要说明。
	/// </summary>
	public class AddToCart : System.Web.UI.Page
	{
		protected System.Web.UI.WebControls.Label lbInfo;
		protected System.Web.UI.HtmlControls.HtmlForm QuickSearchFrom;
		protected System.Web.UI.WebControls.Label lbAllPrice;
		protected System.Web.UI.WebControls.Label lbAllDiscountPrice;
		protected System.Web.UI.WebControls.Label lbDiscount;
		protected System.Web.UI.WebControls.Button btToOrder;
		protected System.Web.UI.WebControls.Button btClearAll;
		protected System.Web.UI.WebControls.DataList dlCart;
		static int nBookID, nUserID;
		protected System.Web.UI.WebControls.Button btGoOn;

		private void Page_Load(object sender, System.EventArgs e)
		{
			if(!IsPostBack)
			{
				if(Object.Equals(Session["UserName"],null))
				{
					Session["ReqestedURL"] = Request.RawUrl;
					Response.Redirect("../Error.aspx");
				}
				else
				{
					nUserID = int.Parse(Session["UserID"].ToString());
					if(Object.Equals(Request["BookID"],null))
					{
						BindData();
					}
					else
					{
						nBookID = int.Parse(Request["BookID"].ToString());
						AddDataToCart();
						BindData();
					}
				}
			}
		}

		private void AddDataToCart()
		{
			string strSql;
			
			// First, query if the book already in the shopping cart
			strSql = "select Quantity from ShoppingCart where BookID=" + nBookID + " and UserID=" + nUserID;
			// If has, give the information, go on databind
			if(IsExist(strSql))
			{
				this.lbInfo.Text = "这本书已经在购物车中了，请直接更改这本书的购买数目。";
			}
			else
			{
				// If haven't, add to the database
				strSql = "Insert into [ShoppingCart] (UserID,BookID,Quantity) Values("
					+ nUserID + ","
					+ nBookID + ","
					+ 1 + ")";
				try
				{
					RobertSoft.BookStore.DBClass.DBBaseClass.ExecuteSQLCmd(strSql);				
				}
				catch
				{
					this.lbInfo.Text = "加入购物车失败！";
					return;
				}			
			}
		}


		private void BindData()
		{
			float fAllPrice, fAllDiscountPrice;
			fAllPrice = 0;
			fAllDiscountPrice = 0;
			// Now, query the shoppingcart detail view, bind data to datalist
			DataTable currentDT;

			RobertSoft.BookStore.OrderBook currentOrder = new RobertSoft.BookStore.OrderBook();

			currentDT = currentOrder.OrderDetail(nUserID);
			DataRow currentDR;
			
			for(int i=0; i < currentDT.Rows.Count; i++)
			{
				currentDR = currentDT.Rows[i];
				fAllPrice += float.Parse(currentDR[4].ToString());
				fAllDiscountPrice += float.Parse(currentDR[5].ToString());
			}
			this.dlCart.DataSource = currentDT.DefaultView;
			this.dlCart.DataBind();

			this.lbAllPrice.Text = fAllPrice.ToString();
			this.lbAllDiscountPrice.Text = fAllDiscountPrice.ToString();
			float fDiscount = fAllPrice - fAllDiscountPrice;
			int nDiscount = (int) (fDiscount * 10);
			fDiscount = (float)nDiscount / 10;
			this.lbDiscount.Text = fDiscount.ToString();
		}

		private bool IsExist(string str)
		{
			try
			{
				RobertSoft.BookStore.DBClass.DBBaseClass.ExecuteSQLForValue(str);
				return true;
			}
			catch
			{
				
				return false;
			}
		}

		#region Web 窗体设计器生成的代码
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// 设计器支持所需的方法 - 不要使用代码编辑器修改
		/// 此方法的内容。
		/// </summary>
		private void InitializeComponent()
		{    
			this.dlCart.ItemCommand += new System.Web.UI.WebControls.DataListCommandEventHandler(this.dlCart_ItemCommand);
			this.dlCart.EditCommand += new System.Web.UI.WebControls.DataListCommandEventHandler(this.dlCart_EditCommand);
			this.dlCart.DeleteCommand += new System.Web.UI.WebControls.DataListCommandEventHandler(this.dlCart_DeleteCommand);
			this.btToOrder.Click += new System.EventHandler(this.btToOrder_Click);
			this.btClearAll.Click += new System.EventHandler(this.btClearAll_Click);
			this.btGoOn.Click += new System.EventHandler(this.btGoOn_Click);
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion

	
		private void dlCart_ItemCommand(object source, System.Web.UI.WebControls.DataListCommandEventArgs e)
		{
			if(e.CommandName == "BookNameClick")
			{
				string url;
				url = "../ShowBookDetail.aspx?ID=" + e.CommandArgument.ToString();
				Response.Redirect(url);
			}
		}

		private void dlCart_DeleteCommand(object source, System.Web.UI.WebControls.DataListCommandEventArgs e)
		{
			int intBookID = int.Parse(e.CommandArgument.ToString());
			DeleteData(intBookID);
			BindData();
			
		}

		private void dlCart_EditCommand(object source, System.Web.UI.WebControls.DataListCommandEventArgs e)
		{
			int intBookID = int.Parse(e.CommandArgument.ToString());
			string number = ((TextBox)(e.Item.Controls[7])).Text.Trim();
			int n = int.Parse(number);
			UpdateData(intBookID,n);
			BindData();
			
		}

		private void UpdateData(int intBookID, int intQuantity)
		{
			string strSql = "Update [ShoppingCart] set Quantity="
				+ intQuantity + " where BookID=" + intBookID + " and UserID=" + nUserID;
			try
			{
				RobertSoft.BookStore.DBClass.DBBaseClass.ExecuteSQLCmd(strSql);		
				this.lbInfo.Text = "修改成功";
			}
			catch
			{
				this.lbInfo.Text = "更新失败！";
				return;
			}			
		}

		private void DeleteData(int intBookID)
		{
			string strSql = "DELETE FROM [ShoppingCart] where BookID=" + intBookID + " and UserID=" + nUserID;
			try
			{
				RobertSoft.BookStore.DBClass.DBBaseClass.ExecuteSQLCmd(strSql);			
				this.lbInfo.Text = "删除成功";
			}
			catch
			{
				this.lbInfo.Text = "删除失败！";
				return;
			}			
		}

		private void btToOrder_Click(object sender, System.EventArgs e)
		{
			if(this.dlCart.Items.Count != 0)
			{
				string strUrl;
				strUrl = "CartToOrder.aspx?UserID=" + nUserID;
				Response.Redirect(strUrl);
			}
			else
			{
				this.lbInfo.Text = "您的购物车中还没有物品！";
				this.lbInfo.ForeColor = Color.Red;
			}
		}

		private void btClearAll_Click(object sender, System.EventArgs e)
		{
			if(this.dlCart.Items.Count != 0)
			{
				string strSql = "DELETE FROM [ShoppingCart] where UserID=" + nUserID;
				try
				{
					RobertSoft.BookStore.DBClass.DBBaseClass.ExecuteSQLCmd(strSql);		
					BindData();
					this.lbInfo.Text = "购物车清空成功";
				}
				catch
				{
					this.lbInfo.Text = "购物车清空失败！";
					return;
				}		
			}
			else
			{
				this.lbInfo.Text = "您的购物车中还没有物品！";
				this.lbInfo.ForeColor = Color.Red;
			}
		}

		private void btGoOn_Click(object sender, System.EventArgs e)
		{
			Response.Redirect("../Default.aspx");
		}
	}
}