ASP.NET MVC 4 (六) 帮助函数

namespace HelperMethods.Models {

    public partial class Person {
        public int PersonId { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public DateTime BirthDate { get; set; }
        public Address HomeAddress { get; set; }
        public bool IsApproved { get; set; }
        public Role Role { get; set; }
    }

    public class Address {
        public string Line1 { get; set; }
        public string Line2 { get; set; }
        public string City { get; set; }
        [Display(Name = "ZIP CODE")]
        public string PostalCode { get; set; }
        public string Country { get; set; }
    }

    public enum Role {
        Admin,
        User,
        Guest
    }
}

namespace HelperMethods.Controllers {
    public class HomeController : Controller {

        public ActionResult Index() {

            ViewBag.Fruits = new string[] { "Apple", "Orange", "Pear" };
            ViewBag.Cities = new string[] { "New York", "London", "Paris" };

            string message = "This is an HTML element: ";

            return View((object)message);
        }

        public ActionResult CreatePerson() {
            return View(new Person { Role = Role.Guest});
        }

        [HttpPost]
        public ActionResult CreatePerson(Person person) {
            return View("DisplayPerson", person);
        }
    }
}

@model string
@{
    Layout = null;
}
@helper ListArrayItems(string[] items)
{
    foreach (string str in items)
    {
        b>@str b>
    }
}
DOCTYPE html>
html>
head>
    meta name="viewport" content="width=device-width" />
    title>Indextitle>
head>
body>
    div>
        Here are the fruits: @ListArrayItems(ViewBag.Fruits)
    div>
    div>
        Here are the cities: @ListArrayItems(ViewBag.Cities)
    div>
    div>
        Here is the message:
        p>@Modelp>
    div>
body>
html> 

namespace HelperMethods.Infrastructure {
    public static class CustomHelpers {

        public static MvcHtmlString ListArrayItems(this HtmlHelper html, string[] list) {

            TagBuilder tag = new TagBuilder("ul");
            foreach(string str in list) {
                TagBuilder itemTag = new TagBuilder("li");
                itemTag.SetInnerText(str);
                tag.InnerHtml += itemTag.ToString();
            }

            return new MvcHtmlString(tag.ToString());
        }

    }
}

@model string
@using HelperMethods.Infrastructure
@{
    Layout = null;
}
DOCTYPE html>
html>
head>
    meta name="viewport" content="width=device-width" />
    title>Indextitle>
head>
body>
    div>
        Here are the fruits: @Html.ListArrayItems((string[])ViewBag.Fruits)
    div>
    div>
        Here are the cities: @Html.ListArrayItems((string[])ViewBag.Cities)
    div>
    div>
        Here is the message:
        p>@Modelp>
    div>
body>
html> 

public ActionResult Index() { 
　　string message = "This is an HTML element: "; 
　　return View((object)message); 
} 

@model string

@{
    Layout = null;
}

DOCTYPE html>
html>
head>
    title>Indextitle>
head>
body>
    p>This is the content from the view:p>
    div>
        Here is the message:
        p>@Modelp>
    div>
body>
html>

... 
div> 
Here is the message: 
p>This is an HTML element: <input>p> 
div> 
... 

public static MvcHtmlString DisplayMessage(this HtmlHelper html, string msg) { 
    string result = String.Format("This is the message: 
{0}", msg); 
　　return new MvcHtmlString(result); 
}

p>This is the content from the helper method:p> 
div style="border: thin solid black; padding: 10px"> 
@Html.DisplayMessage("This is an HTML element: input>") 
div> 

public staticstring DisplayMessage(this HtmlHelper html, string msg) { 
　　return String.Format("This is the message: 
{0}","This is an HTML element: "); } 

public static MvcHtmlStringDisplayMessage(this HtmlHelper html) { 
　　string encodedMessage = html.Encode("This is an HTML element: "); 
　　string result = String.Format("This is the message: 
{0}", encodedMessage); 
　　return new MvcHtmlString(result); 
} 

@model HelperMethods.Models.Person
@{
    ViewBag.Title = "CreatePerson";
}
h2>CreatePersonh2>
form action="/Home/CreatePerson" method="post">
    div class="dataElem">
        label>PersonIdlabel>
        input name="personId" value="@Model.PersonId" />
    div>
    div class="dataElem">
        label>First Namelabel>
        input name="FirstName" value="@Model.FirstName" />
    div>
    div class="dataElem">
        label>Last Namelabel>
        input name="lastName" value="@Model.LastName" />
    div>
    input type="submit" value="Submit" />
form> 

@Html.BeginForm()
div class="dataElem">
    label>PersonIdlabel>
    input name="personId" value="@Model.PersonId" />
div>
div class="dataElem">
    label>First Namelabel>
    input name="FirstName" value="@Model.FirstName" />
div>
div class="dataElem">
    label>Last Namelabel>
    input name="lastName" value="@Model.LastName" />
div>
input type="submit" value="Submit" />
@{Html.EndForm();} 

@using (Html.BeginForm())
{
    div class="dataElem">
        label>PersonIdlabel>
        input name="personId" value="@Model.PersonId" />
    div>
    div class="dataElem">
        label>First Namelabel>
        input name="FirstName" value="@Model.FirstName" />
    div>
    div class="dataElem">
        label>Last Namelabel>
        input name="lastName" value="@Model.LastName" />
    div>
    input type="submit" value="Submit" />
} 

@using (Html.BeginForm("CreatePerson", "Home",new { id = "MyIdValue" }, FormMethod.Post,new { @class = "personClass", data_formType="person"})) { 
...
}

... 
form action="/Home/CreatePerson/MyIdValue" class="personClass" data-formType="person" 
method="post"> 
... 

routes.MapRoute( name: "FormRoute", url: "app/forms/{controller}/{action}" ); 

@using(Html.BeginRouteForm("FormRoute", new {}, FormMethod.Post, new { @class = "personClass", data_formType="person"})) { 
...
}

... 
form action="/app/forms/Home/CreatePerson"class="personClass" data-formType="person" method="post"> 
... 

@model HelperMethods.Models.Person
@{
    ViewBag.Title = "CreatePerson";
}
h2>CreatePersonh2>
@using (Html.BeginRouteForm("FormRoute", new { }, FormMethod.Post,new { @class = "personClass", data_formType = "person" }))
{
    div class="dataElem">
        label>PersonIdlabel>
        @Html.TextBox("personId", @Model.PersonId)
    div>
    div class="dataElem">
        label>First Namelabel>
        @Html.TextBox("firstName", @Model.FirstName)
    div>
    div class="dataElem">
        label>Last Namelabel>
        @Html.TextBox("lastName", @Model.LastName)
    div>
    input type="submit" value="Submit" />
} 

?  ViewBag.DataValue.First.Name
?  ViewBag.DataValue["First"].Name
?  ViewBag.DataValue["First.Name"]
?  ViewBag.DataValue["First"]["Name"]

@model HelperMethods.Models.Person
@{
    ViewBag.Title = "CreatePerson";
}
h2>CreatePersonh2>
@using (Html.BeginRouteForm("FormRoute", new { }, FormMethod.Post,
new { @class = "personClass", data_formType = "person" }))
{
    div class="dataElem">
        label>PersonIdlabel>
        @Html.TextBoxFor(m => m.PersonId)
    div>
    div class="dataElem">
        label>First Namelabel>
        @Html.TextBoxFor(m => m.FirstName)
    div>
    div class="dataElem">
        label>Last Namelabel>
        @Html.TextBoxFor(m => m.LastName)
    div>
    input type="submit" value="Submit" />
} 

div class="dataElem"> 
label>Rolelabel> 
@Html.DropDownListFor(m => m.Role, new SelectList(Enum.GetNames(typeof(HelperMethods.Models.Role)))) 
div>

div class="dataElem"> 
　　label>Rolelabel> 
　　select data-val="true" data-val-required="The Role field is required."  id="Role" name="Role"> 
　　　　option selected="selected">Adminoption> 
　　　　option>Useroption> 
　　　　option>Guestoption> 
　　select> 
div>