無廢話MVC入門教程九[實戰一：用戶注冊與登陸]

朋友炒股兩個月賺了10萬，我幫他推廣一下公眾號，把錢用來投資總比放銀行連通貨膨脹都跑不過里強， 硬核離職，在家炒股　，這是他每天的日志，有些經驗是花錢也買不到的。

本文目標

一、獨立開發用戶注冊與登陸

本文目錄

一、在視圖中使用驗證碼

二、在視圖中使用下拉列表

三、使用FormCollection接收客戶端發送的數據

四、效果預覽與代碼下載

一、在視圖中使用驗證碼

　　MVC中的驗證碼即是在Control中輸出一張圖片顯示在View上

在View的img標簽中添加驗證碼地址“/Image/GetCheckCode/(輸入驗證碼的地址)”，頁面代碼如下：

  <img id="check_img" alt="驗證碼" src="/Image/GetCheckCode/" height="30" width="80" onclick="App.refreshCheckCode('check_img')" /><span><a
            href="javascript:App.refreshCheckCode('check_img');">換一換</a></span>

Control中的接口代碼方法如下：

  public class ImageController : Controller
    {
        public void GetCheckCode()
        {
            CreateCheckCodeImage(GenerateCheckCode());
        }
    }

二、在視圖中使用下拉列表

頁面代碼如下：

   @Html.LabelFor(user => user.Residential)
        @Html.DropDownListFor(user => user.Residential, (SelectList)ViewBag.Residential)

Control代碼如下：

  //取出數據，並通過Helper把數據分解
   AddressHelper addressHelper = AddressHelper.GetInstance();
   addressHelper.GetResidetialItem(GetList());
   //使用ViewBag傳到View
   ViewBag.Residential = addressHelper.ResidetialItem;
   ViewBag.FloorNo = addressHelper.FloorNoItem;
   ViewBag.UnitNo = addressHelper.UnitNoItem;
   ViewBag.DoorplateNo = addressHelper.DoorplateNoItem;



   public class AddressHelper
    {
        //單例
        private AddressHelper() { }
        private static AddressHelper Instance = new AddressHelper();
        public static AddressHelper GetInstance()
        {
            return Instance;
        }

        public SelectList ResidetialItem { get; private set; }
        public SelectList FloorNoItem { get; private set; }
        public SelectList UnitNoItem { get; private set; }
        public SelectList DoorplateNoItem { get; private set; }

        //獲取小區列表
        public void GetResidetialItem(List<Model.Address> AddressItem)
        {
            List<SelectListItem> ResidetialItem = new List<SelectListItem>();
            List<SelectListItem> FloorNoItem = new List<SelectListItem>();
            List<SelectListItem> UnitNoItem = new List<SelectListItem>();
            List<SelectListItem> DoorplateNoItem = new List<SelectListItem>();
            foreach (Model.Address address in AddressItem)
            {
                if (address.Type == 1)
                {
                    ResidetialItem.Add(new SelectListItem { Value = address.AddressID.ToString(), Text = address.Name });
                }
                if (address.Type == 2)
                {
                    FloorNoItem.Add(new SelectListItem { Value = address.AddressID.ToString(), Text = address.Name });
                }
                if (address.Type == 3)
                {
                    UnitNoItem.Add(new SelectListItem { Value = address.AddressID.ToString(), Text = address.Name });
                }
                if (address.Type == 4)
                {
                    DoorplateNoItem.Add(new SelectListItem { Value = address.AddressID.ToString(), Text = address.Name });
                }
            }
            this.ResidetialItem = new SelectList(ResidetialItem.AsEnumerable(), "Value", "Text");
            this.FloorNoItem = new SelectList(FloorNoItem.AsEnumerable(), "Value", "Text");
            this.UnitNoItem = new SelectList(UnitNoItem.AsEnumerable(), "Value", "Text");
            this.DoorplateNoItem = new SelectList(DoorplateNoItem.AsEnumerable(), "Value", "Text");
        }
    }

ViewBag.Residential：在Control與View中傳遞數據

@Html.DropDownListFor：接收SelectList類型的數據，取到數據后要把List轉換成該類型，此例在AddressHelper進行的轉換

三、使用FormCollection接收客戶端發送的數據

MVC中可以使用強類型在Control與View中進行數據傳遞、也可以使用FormCollection接收數據

此例中我們把驗證碼用FormCollection向后台傳遞，View代碼如下：

<input type="text" name="checkCode" />

Control中的代碼如下：

        [HttpPost]//注冊時處理回發
        public ActionResult Regedit(Model.User user, FormCollection form)
        {
            //取出數據，並通過Helper把數據分解
            AddressHelper addressHelper = AddressHelper.GetInstance();
            addressHelper.GetResidetialItem(GetList());
            //使用ViewBag傳到View
            ViewBag.Residential = addressHelper.ResidetialItem;
            ViewBag.FloorNo = addressHelper.FloorNoItem;
            ViewBag.UnitNo = addressHelper.UnitNoItem;
            ViewBag.DoorplateNo = addressHelper.DoorplateNoItem;

            //校驗驗證碼
            if (form["checkCode"] != null && form["checkCode"].ToString() == Session["CheckCode"].ToString())
            {
                //校驗其他表單元素
                if (ModelState.IsValid)
                {
                    DemoRepository.User.Add(user);
                    MessageBox.ShowAndRedirect(this, "注冊成功，請登陸！", "/User/Login");
                }
            }
            else
            {
                MessageBox.Show(this, "驗證碼不正確！");
            }
            return View();
        }

四、效果預覽與代碼下載

1.注冊

2.登陸

3.代碼下載

數據文件在文件夾根目錄下，一切盡在不言中，直接看代碼吧

[點擊下載] 

五、補：Cookies的使用

登陸的時候注冊Cookies

        [HttpPost]//登陸時回發處理
        public ActionResult Login(Model.User user)
        {
            if (ModelState.IsValid)
            {
                Model.User newUser = Repository.User.UserLogin(user);
                //檢測用戶名和密碼
                if (newUser != null)
                {
                    DateTime Expires = DateTime.Now;
                    if (user.Remember == true)
                        Expires = DateTime.Now.AddDays(365);

                    Dictionary<string, string> CookieValues = new Dictionary<string, string>();
                    CookieValues.Add("UserID", newUser.UserID.ToString());
                    CookieValues.Add("UserName", newUser.UserName);
                    CookieHelper cookieHelper = new CookieHelper();

                    cookieHelper.SetCookie(CookieValues, Expires);
                    Response.Redirect("/Manage/Main");
                }
                else
                {
                    MessageBox.Show(this, "用戶名或密碼不正確！");
                }
            }
            //客戶端顯示
            return View();
        }

此處使用cookieHelper幫助類管理Cookies，類代碼如下：

    public class CookieHelper
    {
        private string name = "User";   //Cookie名稱

        //是否已經被創建
        public bool IsCreate
        {
            get
            {
                HttpCookie Cookie = HttpContext.Current.Request.Cookies[this.name];
                if (Cookie != null)
                    return true;
                else
                    return false;
            }
        }

        //設置Cookies
        public void SetCookie(Dictionary<string, string> Values, DateTime Expires)
        {
            HttpCookie Cookie = new HttpCookie(this.name);
            foreach (string key in Values.Keys)
            {
                Cookie.Values.Add(key, Values[key]);
            }
            Cookie.Expires = Expires;
            HttpContext.Current.Response.Cookies.Add(Cookie);
        }

        //獲取Cookie
        public HttpCookie GetCookie()
        {
            return HttpContext.Current.Request.Cookies[this.name];
        }

        //清空Cookie
        public void ClearCookie()
        {
            HttpCookie Cookie = HttpContext.Current.Request.Cookies[this.name];
            Cookie.Expires = DateTime.Now.AddDays(-1);
            HttpContext.Current.Response.Cookies.Add(Cookie);
        }
    }

 鑒於@BangQ 的回復提出的疑問，關於Cookies安全問題，請具體查閱資料。

六、這個例子代碼比較多，具體請下載代碼查看。

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