WebForm Session value (storage of temporary data) and extended properties--(Shopping cart practice)

Page Pass Value:
1.QueryString Transmit Value
Write on the source page: Response.Redirect ("main.aspx?uid=" +uid+ "&pwd=" +pwd);
On the target page: request["UID"]. ToString ();
2.Session * * * *
Features: Can save anything, each user will generate a specific session,session is stored in the service,
General default storage 20 minutes, 20 minutes after expiration
Usage: On the login page: session["UID"] = UID;
On use page: session["UID"]. ToString ();
3.Cookie * * * *
Features: Default never expires, you can set its expiration time, cookie is stored in the client's
Usage: At Login interface://New Cookie Object
HttpCookie cookie_name = new HttpCookie ("UID");
Assign value
Cookie_name. Value = UID;
Write to Cookie Inside
Response.appendcookie (Cookie_name);

In use interface: request.cookies["UID"]. Value.tostring ();
4.Application
Features: It is a common
Usage: On the source page: application["UID"] = UID;
On the target page: Application.Lock ();
Label1.Text = application["UID"]. ToString ();
Application.UnLock ();

Example Shopping Cart:

Goal: How to build a temporary database table with the conversion of the session and list collection

1. Browse the Product interface

<%@ Page Language= "C #"AutoEventWireup= "true"CodeFile= "Main.aspx.cs"Inherits= "Main"%><! DOCTYPE html>#Eval("Ids")%></td> <td bgcolor= "#FFFFFF" ><%#Eval("Name")%></td > <td bgcolor= "#FFFFFF" ><%#Eval("Price")%></td> <td bgcolor= "#FFFFFF" ><% #Eval("Source")%></td> <td bgcolor= "#FFFFFF" ><%#Eval("Numbers")% ></td> <td bgcolor= "#FFFFFF" ><a href= "chuli.aspx?code=<% #Eval (" Ids ")%>" > Purchase </a> </td> </tr> </ItemTemplate> <FooterTemplate> </table> </FooterTemplate> </asp :repeater> <br/> <br/> <asp:label id= "lblts" runat= "Server" ></asp:Label> </div> 

CS Code

UsingSystem;usingSystem.collections.generic;usingSystem.linq;usingSystem.web;usingSystem.web.ui;usingSystem.web.ui.webcontrols;public Partial classmain:system.web.ui.page{protected void Page_Load (objectsender, EventArgs e) {if (!IsPostBack) {if (session["UID"] = null) {Firutdatacontext context = new firutdatacontext (); Repeater1.datasource = context. Fruit; Repeater1.databind (); if (session["cart"] = null) {list<orderdetails> List = session["cart"] as list<orderdetails>; int SL = list. Count (); Decimal ZJ = Convert.todecimal (list. Sum (p = p.count * p.jiage)); Lblts.text = "Shopping Cart:" +sl+ "items, Total Price:" +zj+ "Yuan. "; } } else {Response.Redirect ("denglu.aspx"),}}}protected void LinkButton1_Click (Object sender, EventArgs e) {Response.Redirect ("main.aspx");} protected void Linkbutton2_click (Object sender, EventArgs e) {response.re Direct ("yue.aspx");} protected void Linkbutton3_click (Object sender, EventArgs e) {Response.Redirect (" Gouwuche.aspx "); }}

2. Click on the purchase interface:

The ASPX code has no things.

CS Code

UsingSystem;usingSystem.collections.generic;usingSystem.linq;usingSystem.web;usingSystem.web.ui;usingSystem.web.ui.webcontrols;public Partial classchuli:system.web.ui.page{protected void Page_Load (objectsender, EventArgs e) {String code = request["Code"]. ToString (); if (session["Cart"]! = NULL) {list<orderdetails> Listall = session["Cart"] as List<orderdetails>; var query = Listall. Where (p = = P.fruitcode = = code), if (query. Count () > 0) {orderdetails data1 = query. First (); Listall. Remove (DATA1); Data1. Count = Data1. Count + 1;//listall. ADD (DATA1); session["Cart"] = listall;} else {OrderDetails data2 = new OrderDetails (); data2. Fruitcode = code; data2. Count = 1; listall. ADD (DATA2); session["Cart"] = Listall;}} else {Firutdatacontext context = new firutdatacontext (); list<orderdetails> list = new list<orderdetails>(); OrderDetails data = new OrderDetails (); data. Fruitcode = code; data. Count = 1; list. ADD (data); session["Cart"] = list;} Response.Redirect ("main.aspx");}}              

3. Browse the Shopping Cart interface

<%@ Page Language= "C #"AutoEventWireup= "true"CodeFile= "GouWuChe.aspx.cs"Inherits= "Gouwuche"%><! DOCTYPE html>#Eval("Shangpinname")%></td> <td bgcolor= "#FFFFFF" ><%#Eval("jiage")% ></td> <td bgcolor= "#FFFFFF" ><%#Eval("Count")%></td> <td bgcolor= "# FFFFFF "><a href=" shanchu.aspx?code=<% #Eval ("Fruitcode")%> "> Delete </a></td> </tr> </ItemTemplate> <FooterTemplate> </table> </FooterTemplate> </asp:Repeater> <br/ > <br/> <asp:label id= "lblts" runat= "Server" forecolor= "#CC0000" ></asp:Label> <br/> <br /> <asp:button id= "Button1" runat= "Server" onclick= "Button1_Click" text= "Submit Order"/> <br/> <br/> < Asp:label id= "lblsure" runat= "Server" forecolor= "#CC0000" ></asp:Label> <br/> </div> </div > </form></body>        

CS Code:

UsingSystem;usingSystem.collections.generic;usingSystem.linq;usingSystem.web;usingSystem.web.ui;usingSystem.web.ui.webcontrols;public Partial classgouwuche:system.web.ui.page{protected void Page_Load (objectsender, EventArgs e) {if (!IsPostBack) {if (session["Cart"]! = NULL) {list<orderdetails> List = session["Cart"] as List<orderdetails>; Repeater1.datasource =List Repeater1.databind (); } else{Lblts.text = "There are no items in the shopping cart! "; }}} protected void LinkButton1_Click (objectsender, EventArgs e) {Response.Redirect ("main.aspx")); } protected void Linkbutton2_click (objectsender, EventArgs e) {Response.Redirect ("yue.aspx")); } protected void Linkbutton3_click (objectsender, EventArgs e) {Response.Redirect ("gouwuche.aspx")); } protected void Button1_Click (objectsender, EventArgs e) {list<orderdetails> List = session["Cart"] as List<orderdetails>; Firutdatacontext context = newFirutdatacontext (); BOOL IsOk = True; foreach (OrderDetails data inlist) {int SL =Data. Count.value; var query = context. Fruit.where (P=>p.ids = =Data. Fruitcode); int KC =Query. First (). Numbers.value; if (SL <=KC) {IsOk = IsOk && True; } else{IsOk = IsOk && false; Lblsure.text + = query. First (). Name + "Insufficient inventory! "; }} if(IsOk) {if (session["UID"]! = NULL) {String uid = session["UID"]. ToString (); var query = context. Login.where (P=>p.username = =UID); Decimal ye =Query. First (). Account.value; Decimal ZJ = list. Sum (p = p.jiage *P.count). Value; if (Ye >=ZJ) {//Minus inventory foreach (OrderDetails data inlist) {int SL =Data. Count.value; var Query2 = context. Fruit.where (p = p.ids = = data. Fruitcode); Query2. First (). Numbers = Query2. First (). Numbers.value- data. Count; Context. SubmitChanges (); }//minus balance var query3 = context. Login.where (P=>p.username = =  uid); Query3. First (). account = Query3. First (). Account.value- zj; context. SubmitChanges (); Add Order Orders Data1 = new  orders (); Random r = new  random (), String ordercode = DateTime.Now.ToString ("yyyymmddhhmmssms") + r.next (+ ). ToString (); Data1. Code =  ordercode; data1. UserName =  uid; data1. Ordertime =  DateTime.Now; context. Orders.insertonsubmit (DATA1); Context. SubmitChanges (); Add Order Details table foreach (OrderDetails data in  list) {data. Ordercode =  Ordercode;} context. Orderdetails.insertallonsubmit (list); Context. SubmitChanges (); } else  {lblsure.text + = "Insufficient balance! ";}} else  {Response.Redirect ("denglu.aspx" )}}}}         

4, the shopping cart Click Delete, the user interface

CS Code

Using system;using system.collections.generic;using system.linq;using system.web;using  System.web.ui;using system.web.ui.webcontrols;public Partial class shanchu:system.web.ui.page{protected void Page_Load (Object sender, EventArgs e) {list<orderdetails> List = session["Cart"] as list<orderdetails& Gt ; string code = request["Code"]. ToString (); var query = list. Where (p = = P.fruitcode = = code), if (query. First (). Count.value > 1) {query. First (). count--;} else {list. Remove (query. First ()); } session["Cart"] = list; Response.Redirect ("gouwuche.aspx");}}              

5. View account Interface (none)

6. Extended OrderDetails attribute (teacher Li version)

public partial class orderdetails{    private decimal jiage;    Public decimal jiage    {        get         {            Firutdatacontext context = new firutdatacontext ();            var query = context. Fruit.where (P=>p.ids = = Fruitcode); Fruit data = query. First (); return data. Price.value; } set {jiage = value;} private string shangpinname; public string shangpinname {get {Firutdataco ntext context = new firutdatacontext (); var query = context. Fruit.where (p = p.ids = = Fruitcode); Fruit data = query. First (); return data. Name; } set {shangpinname = value;}}              

A different version

 using  system;using  system.collections.generic;using  system.linq;using  system.web;/// <summary>///ORDERDETAILSBF Summary description///</summary>public partial class  orderdetails{private Dataclasse Sdatacontext _context = new  dataclassesdatacontext (); public string  fruitname {//correlated subqueries, Use the fruit number in the order table to query fruit table fruit name get  {var query = _context.fruit.where (p = = P.ids = = This . Fruitcode); if (query. Count () > 0 ) {return  query. First (). Name; } return "" ;}} Public decimal  Fruitprice {get  {var query = _context.fruit.where (p = = P.ids = = this . _fruitcode); (Query. Count () > 0 ) {return  query. First (). Price.value; } return 0 ;}} public list<orderdetails>  Select () {return  _context.orderdetails.tolist ();}}     

For example, two tables have directly related foreign key relationships (such as the nation table and the Nation property in the info table)

public partial class info{public    string nname    {        get        {            return this. nation1.name;        }}}

WebForm Session value (storage of temporary data) and extended properties--(Shopping cart practice)