ASP.NET MVC 之控制器与视图之间的数据传递

2022-10-02 10:13:19

今天，我们来谈谈控制器与视图之间的数据传递。

数据传递，指的是视图与控制器之间的交互，包括两个方向上的数据交互，一个是把控制器的数据传到视图中，在视图中如何显示数据，一个是把视图数据传递到控制器中，

如何在控制器中获取，处理这些数据。

ASP.NET MVC 中所有控制器都继承Controller类，而Controller又继承自ControllerBase，而ControllerBase下又包含ViewData以及TempData视图数据字典。

一，使用ViewData传递数据

ViewData 只在当前 Action 中有效，生命周期和 View 相同，属于弱类型数据。用法与C#中字典用法相似，以键值对的方式进行存储。

ViewData可以存储任何数据类型，如类，DataTable，DataSet，json等。

用法举例：

public ActionResult Index()

{

        ViewData["mydata"] = "index";

         return View();

}

前台代码：

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<dynamic>" %>

<!DOCTYPE html>

<html>

<head runat="server">

    <meta name="viewport" content="width=device-width" />

    <title>Index</title>

</head>

<body>

    <div>

        <%=ViewData["mydata"] %>

    </div>

</body>

</html>

二，使用TempData传递数据

TempData与ViewData类似，以键值对的方式进行存储，保存在Session之中,进行一次读取之后Session就会消失,变为null。看下面代码：

 public ActionResult Index()

        {

            //AVON.DMS.DAL.Entities DMS = new AVON.DMS.DAL.Entities();

            //AVON.DMS.Model.REP A = DMS.REP.SingleOrDefault<AVON.DMS.Model.REP>(t => t.NO == "00561874");

            //AVON.DMS.BLL.Rep repBLL = new AVON.DMS.BLL.Rep();

            //AVON.DMS.Model.REP A = repBLL.GetFromRep("00561874");

            //ViewData["mydata"] = A.JOINDATE;

            ViewData["mydata"] = "index";

            TempData["mytemp"] = "huihui";

            return View();

        }

前端代码：

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<dynamic>" %>

<!DOCTYPE html>

<html>

<head runat="server">

    <meta name="viewport" content="width=device-width" />

    <title>Index</title>

</head>

<body>

    <div>

        <%=ViewData["mydata"] %>

        <%--<%=TempData["mytemp"] %>--%>

        <a href="add">跳转到下一页</a>

    </div>

</body>

</html>

在浏览器输入地址，http://localhost:7449/dms/index，显示如下：

ASP.NET MVC 之控制器与视图之间的数据传递

点击"跳转到下一页"，进入http://localhost:7449/dms/add，显示如下：

ASP.NET MVC 之控制器与视图之间的数据传递

我们看看add这个Action的代码：

 public ActionResult Add()

        {

            ViewData["mydata"] = TempData["mytemp"];

            //Session.Remove("temp");

            return View();

        }

前端：

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<dynamic>" %>

<!DOCTYPE html>

<html>

<head runat="server">

    <meta name="viewport" content="width=device-width" />

    <title>Add</title>

</head>

<body>

    <div>

        add

        <%=ViewData["mydata"] %>

        <a href="index">跳转到上一页</a>

    </div>

</body>

</html>

可见，add获取到了TempData["mytemp"]的值。我们尝试刷新一下http://localhost:7449/dms/add，显示如下：

ASP.NET MVC 之控制器与视图之间的数据传递

ViewData["mttemp"]的值已经变为null，所以，可以看出TempData的值一旦读取，就会失效。需重新赋值。

三，使用Model传递数据

ViewData与TempData都是弱类型数据，那么如果我们想传递强类型数据，应该怎样编写代码呢？代码如下：

public ActionResult Detail()

        {

            DRMModel.Dealer dealer = new DRMModel.Dealer();

            dealer.RecruiterID = "";

            dealer.Recruiter = "";

            dealer.NationalID = "";

            dealer.dealer_name = "dsdsds";

            dealer.sex = "";

            dealer.BirthYear = "";

            dealer.BirthMonth = "";

            dealer.BirthDay = "";

            var Model = dealer;

            return View(Model);

        }

右击detail方法，添加视图，勾选 Create a strongly-typed view,如下图：

ASP.NET MVC 之控制器与视图之间的数据传递

点击添加之后，编写如下代码：

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<DRMModel.Dealer>" %>

<!DOCTYPE html>

<html>

<head runat="server">

    <meta name="viewport" content="width=device-width" />

    <title>Detail</title>

</head>

<body>

    <div>

        <%=Model.dealer_name %>

    </div>

</body>

</html>

在浏览器输入地址：http://localhost:55706/home/detail，显示如下：

ASP.NET MVC 之控制器与视图之间的数据传递

当然，你也可以编写更为复杂的类，传递多个数据对象进行数据绑定。如下图：

 public ActionResult Bind()

        {

            DRMModel.NewDealer newDealer = new DRMModel.NewDealer();

            DRMModel.Dealer dealer = new DRMModel.Dealer();

            dealer.RecruiterID = "";

            dealer.Recruiter = "";

            dealer.NationalID = "";

            dealer.dealer_name = "dsdsds";

            dealer.sex = "";

            dealer.BirthYear = "";

            dealer.BirthMonth = "";

            dealer.BirthDay = "";

            DRMModel.Contact contact = new DRMModel.Contact();

            DRMModel.HouseAddress ha = new DRMModel.HouseAddress();

            DRMModel.RDaddress rd = new DRMModel.RDaddress();

            DRMModel.SendAddress sa = new DRMModel.SendAddress();

            newDealer.Contact = contact;

            newDealer.HouseAddress = ha;

            newDealer.RDaddress = rd;

            newDealer.SendAddress = sa;

            newDealer.Dealer = dealer;

            var Model = newDealer;

            return View(Model);

        }

以上都是谈了控制器往视图传递数据，那么，控制器怎么获取视图提交的数据呢？今天，我们只介绍获取Post方式传送数据的方法。

假设，表单通过Post方式提交了，下列数据：RecruiterID = "1";Recruiter = "2";NationalID = "2";dealer_name = "dsdsds";

看以下方法代码：

/// <summary>

        /// 处理表单提交数据，方法1:使用传统的Request请求取值

        /// </summary>

        /// <returns></returns>

        [HttpPost]

        public ActionResult AcceptFrom()

        {

            ViewData["RecruiterID"] = Request.Form["RecruiterID"];

            ViewData["Recruiter"] = Request.Form["Recruiter"];

            ViewData["NationalID"] = Request.Form["NationalID"];

            ViewData["dealer_name"] = Request.Form["dealer_name"];

            return View();

        }

        /// <summary>

        /// 处理表单提交数据，方法2:Action参数名与表单元素name值一一对应

        /// </summary>

        /// <param name="RecruiterID"></param>

        /// <param name="Recruiter"></param>

        /// <param name="NationalID"></param>

        /// <param name="dealer_name"></param>

        /// <returns></returns>

        [HttpPost]

        public ActionResult AcceptbyPara(string RecruiterID, string Recruiter, string NationalID, string dealer_name)

        {

            ViewData["RecruiterID"] = RecruiterID;

            ViewData["Recruiter"] = Recruiter;

            ViewData["NationalID"] = NationalID;

            ViewData["dealer_name"] = dealer_name;

            return View();

        }

        /// <summary>

        /// 处理表单提交数据，方法3:从MVC封装的FormCollection容器中读取

        /// </summary>

        /// <param name="form"></param>

        /// <returns></returns>

        [HttpPost]

        public ActionResult AcceptCollection(FormCollection form)

        {

            ViewData["RecruiterID"] = form["RecruiterID"];

            ViewData["Recruiter"] = form["Recruiter"];

            ViewData["NationalID"] = form["NationalID"];

            ViewData["dealer_name"] = form["dealer_name"];

            return View();

        }

        /// <summary>

        /// 处理表单提交数据，方法4:使用实体作为Action参数传入，前提是提交的表单元素名称与实体属性名称一一对应

        /// </summary>

        /// <param name="dealer"></param>

        /// <returns></returns>

        [HttpPost]

        public ActionResult AcceptbyModel(DRMModel.Dealer dealer)

        {

            ViewData["RecruiterID"] = dealer.RecruiterID;

            ViewData["Recruiter"] = dealer.Recruiter;

            ViewData["NationalID"] = dealer.NationalID;

            ViewData["dealer_name"] = dealer.dealer_name;

            return View();

        }

假如。我们要传json数据呢，又应该怎么处理呢？看以下的例子：

我在HomeController 下的Index方法添加如下代码，模拟Post提交json数据。

 public ActionResult Index()

        {

            DRMModel.NewDealer newDealer = new DRMModel.NewDealer();

            DRMModel.Dealer dealer = new DRMModel.Dealer();

            dealer.RecruiterID = "";

            dealer.Recruiter = "";

            dealer.NationalID = "";

            dealer.dealer_name = "dsdsds";

            dealer.sex = "";

            dealer.BirthYear = "";

            dealer.BirthMonth = "";

            dealer.BirthDay = "";

            DRMModel.Contact contact = new DRMModel.Contact();

            DRMModel.HouseAddress ha = new DRMModel.HouseAddress();

            DRMModel.RDaddress rd = new DRMModel.RDaddress();

            DRMModel.SendAddress sa = new DRMModel.SendAddress();

            newDealer.Contact = contact;

            newDealer.HouseAddress = ha;

            newDealer.RDaddress = rd;

            newDealer.SendAddress = sa;

            newDealer.Dealer = dealer;

            JavaScriptSerializer json = new JavaScriptSerializer();

            string postdata = json.Serialize(newDealer);

            //postdata = "RecruiterID=1&Recruiter=2&NationalID=1&dealer_name=fafaf&sex=1&BirthYear=1989&BirthMonth=09&BirthDay=01";

            string pageHtml = "";

            //var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://avondms.avon.com.tw/DMS/DMSApi/api/Newdealer/add");

            var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://localhost:55706/home/add");

            //httpWebRequest.ContentType = "text/json";

            //httpWebRequest.ContentType = "application/x-www-form-urlencoded";

            httpWebRequest.ContentType = "application/json";

            httpWebRequest.Method = "POST";

            using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))

            {

                streamWriter.Write(postdata);

                streamWriter.Flush();

                streamWriter.Close();

            }

            var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();

            using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))

            {

                pageHtml = streamReader.ReadToEnd();

            }

            ViewData["pram1"] = pageHtml;

            return View();

        }

在HomeController add方法添加如下代码：

   [HttpPost]

        public string add(DRMModel.NewDealer newDealer)

        {

            //string rtn = Request.Form["dealer_name"];

            string rtn = newDealer.Dealer.dealer_name;

            return rtn;

        }

在浏览器中输入地址：http://localhost:55706/home/index,显示如下：

ASP.NET MVC 之控制器与视图之间的数据传递

由此可见，ASP.NET MVC 可把json数据转化为C#中的强类型数据，只要数据一一对应。

好了，今天写到这里，希望对您有所帮助，O(∩_∩)O哈哈~

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