ASP.NET MVC學習筆記-Controller與View傳值

在asp.net2.0的網頁開發模式下，我們一般通過直將訪問頁面控件，將值寫入到頁面，但在Asp.net MVC模式下，已不能在Controller中再去訪問頁面控件了，要如何才能給View頁面傳值呢？

在Controller中有兩個字典(ViewData和TempData)來實現View之間的值傳遞, 在ControllerBase類聲明中我們就可以看到：

namespace System.Web.Mvc
{
// 摘要:
// Represents the base class for all MVC controllers.
public abstract class ControllerBase : MarshalByRefObject, IController
{
protected ControllerBase();
// 摘要:
// Gets or sets the controller context.
public ControllerContext ControllerContext { get; set; }
//
// 摘要:
// Gets or sets the temporary data.
public TempDataDictionary TempData { get; set; }
//
// 摘要:
// Gets or sets a value indicating whether the request is valid.
public bool ValidateRequest { get; set; }
//
// 摘要:
// Gets or sets the value provider.
public IDictionary<string, ValueProviderResult> ValueProvider { get; set; }
//
// 摘要:
// Gets or sets the view data.
public ViewDataDictionary ViewData { get; set; }
// 摘要:
// Executes the specified request context.
//
// 參數:
// requestContext:
// The request context.
protected virtual void Execute(RequestContext requestContext);
//
// 摘要:
// Executes the core.
protected abstract void ExecuteCore();
//
// 摘要:
// Initializes the specified request context.
//
// 參數:
// requestContext:
// The request context.
protected virtual void Initialize(RequestContext requestContext);
}
}

namespace System.Web.Mvc
{
    // 摘要:
    //     Represents the base class for all MVC controllers.
    public abstract class ControllerBase : MarshalByRefObject, IController
    {
        protected ControllerBase();
        // 摘要:
        //     Gets or sets the controller context.
        public ControllerContext ControllerContext { get; set; }
        //
        // 摘要:
        //     Gets or sets the temporary data.
        public TempDataDictionary TempData { get; set; }
        //
        // 摘要:
        //     Gets or sets a value indicating whether the request is valid.
        public bool ValidateRequest { get; set; }
        //
        // 摘要:
        //     Gets or sets the value provider.
        public IDictionary<string, ValueProviderResult> ValueProvider { get; set; }
        //
        // 摘要:
        //     Gets or sets the view data.
        public ViewDataDictionary ViewData { get; set; }
        // 摘要:
        //     Executes the specified request context.
        //
        // 參數:
        //   requestContext:
        //     The request context.
        protected virtual void Execute(RequestContext requestContext);
        //
        // 摘要:
        //     Executes the core.
        protected abstract void ExecuteCore();
        //
        // 摘要:
        //     Initializes the specified request context.
        //
        // 參數:
        //   requestContext:
        //     The request context.
        protected virtual void Initialize(RequestContext requestContext);
    }
}

而在ViewResultBase中我們同樣可以看到它也含有這兩個字典存在:

// 摘要:
// Base class used to supply the model to the view and then render the view
// to the response.
public abstract class ViewResultBase : ActionResult
{
protected ViewResultBase();
// 摘要:
// Gets or sets the System.Web.Mvc.TempDataDictionary for this result.
public TempDataDictionary TempData { get; set; }
//
// 摘要:
// Gets or sets the System.Web.Mvc.IView that is rendered to the response.
public IView View { get; set; }
//
// 摘要:
// Gets or sets the view data System.Web.Mvc.ViewDataDictionary for this result.
public ViewDataDictionary ViewData { get; set; }
//
// 摘要:
// Gets or sets the view engines (System.Web.Mvc.ViewEngineCollection) associated
// with this result.
public ViewEngineCollection ViewEngineCollection { get; set; }
//
// 摘要:
// Gets or sets the name of the view to be rendered.
public string ViewName { get; set; }
// 摘要:
// When called by the action invoker, renders the view to the response.
//
// 參數:
// context:
// The context within which the result is executed.
public override void ExecuteResult(ControllerContext context);
//
// 摘要:
// When overridden, returns the System.Web.Mvc.ViewEngineResult used to render
// the view.
//
// 參數:
// context:
// The context.
//
// 傳回:
// The view engine.
protected abstract ViewEngineResult FindView(ControllerContext context);
}

// 摘要:
    //     Base class used to supply the model to the view and then render the view
    //     to the response.
    public abstract class ViewResultBase : ActionResult
    {
        protected ViewResultBase();
        // 摘要:
        //     Gets or sets the System.Web.Mvc.TempDataDictionary for this result.
        public TempDataDictionary TempData { get; set; }
        //
        // 摘要:
        //     Gets or sets the System.Web.Mvc.IView that is rendered to the response.
        public IView View { get; set; }
        //
        // 摘要:
        //     Gets or sets the view data System.Web.Mvc.ViewDataDictionary for this result.
        public ViewDataDictionary ViewData { get; set; }
        //
        // 摘要:
        //     Gets or sets the view engines (System.Web.Mvc.ViewEngineCollection) associated
        //     with this result.
        public ViewEngineCollection ViewEngineCollection { get; set; }
        //
        // 摘要:
        //     Gets or sets the name of the view to be rendered.
        public string ViewName { get; set; }
        // 摘要:
        //     When called by the action invoker, renders the view to the response.
        //
        // 參數:
        //   context:
        //     The context within which the result is executed.
        public override void ExecuteResult(ControllerContext context);
        //
        // 摘要:
        //     When overridden, returns the System.Web.Mvc.ViewEngineResult used to render
        //     the view.
        //
        // 參數:
        //   context:
        //     The context.
        //
        // 傳回:
        //     The view engine.
        protected abstract ViewEngineResult FindView(ControllerContext context);
    }

由此可以看出,Controller通過ViewData,TempData傳通到ViewResult中，然後再由ViewResult傳遞到ViewPage中來實現值傳遞的。

1.TempData和ViewData的應用

ViewData只對當前Action有效，而TempData有點類似於Session, 可在所有View訪問，一般用於記錄錯誤信息.

Action代碼:

public ActionResult Index()
{
ViewData["Message"] = "Welcome to ASP.NET MVC!";
return View();
}

頁面代碼：

<h2><%= Html.Encode(ViewData["Message"]) %></h2>

TempData使用方式與View使用方式一致.

2. ViewData與TextBox實現自動綁定

利用HtmlHelper創建TextBox時，使用名稱與ViewData中的Key一致，就會自動實現值綁定,如:

Name:<%= Html.TextBox("name") %>

名稱不相同的情況下，也可以利用TextBox的重載傳值:

Name:<%= Html.TextBox("name", ViewData["Nm"]) %>

3.View向Controller傳值

1). 利用Action參數

<form name="form1" action="/Home/Index" method="post">
Name:<input type="text" name="name" /><br />
Sex: <input type="text" name="sex" />
<input type="submit" value="submit" />
</form>
<%
if (ViewData["name"] != null)
{
Response.Write("your name is:" + ViewData["name"] + ", your sex is:" + ViewData["sex"]);
}
%>
:
public ActionResult Index(string name, string sex)
{
ViewData["Message"] = "Welcome to ASP.NET MVC!";
ViewData["name"] = name;
ViewData["sex"] = sex;
return View();
}

2).利用Request.From或Request.QueryString

public ActionResult Index()
{
ViewData["Message"] = "Welcome to ASP.NET MVC!";
ViewData["name"] = Request.Form["name"];
ViewData["sex"] = Request.Form["sex"];
return View();
}

3). 利用FormCollection獲取頁面值

public ActionResult Index(FormCollection form)
{
ViewData["Message"] = "Welcome to ASP.NET MVC!";
User u=new User();
u.Name = form["Name"];
u.Password = form["Password"];
return View(u);
}

4.傳遞強類型

1).添加一個傳遞強類型Model的Action

public ActionResult ModelDemo()
{
User u= new User() { UserName="li", Password="abcde" };
return View(u);
}

對應的View也需要繼隨於ViewPage<User>, 對應代碼如下:

<p>
<%User u = (User)ViewData.Model;%>
UserName:
<%= Html.Encode(u.UserName) %>
</p>
<p>
Password:
<%= Html.Encode(u.Password) %>
</p

ASP.NET MVC學習筆記-Controller與View傳值

【簡寫Mybatis-02】註冊機的實現以及SqlSession處理

手繪二維碼

.NET藉助虛擬網卡實現一個簡單異地組網工具

ASP.NET MVC學習筆記-Controller與View傳值

codeproject

只有十句話，我卻看了十分鐘

十個讓你變成糟糕的程序員的行爲

優秀程序員之道

Mac下配置sublime實現LaTeX

https://yachay.unat.edu.pe/blog/index.php?comment_area=format_blog&comment_component=blog&comment_co

linux以太網驅動總結