HTML.ActionLink方法

Question

Let's say I have a class

public class ItemController:Controller
{
    public ActionResult Login(int id)
    {
        return View("Hi", id);
    }
}

On a page that is not located at the Item folder, where ItemController resides, I want to create a link to the Login method. So which Html.ActionLink method I should use and what parameters should I pass?

Specifically, I am looking for the replacement of the method

Html.ActionLink(article.Title,
    new { controller = "Articles", action = "Details",
          id = article.ArticleID })

that has been retired in the recent ASP.NET MVC incarnation.

Answer 1

I think what you want is this:

ASP.NET MVC1

Html.ActionLink(article.Title, 
                "Login",  // <-- Controller Name.
                "Item",   // <-- ActionMethod
                new { id = article.ArticleID }, // <-- Route arguments.
                null  // <-- htmlArguments .. which are none. You need this value
                      //     otherwise you call the WRONG method ...
                      //     (refer to comments, below).
                )

This uses the following method ActionLink signature:

public static string ActionLink(this HtmlHelper htmlHelper, 
                                string linkText,
                                string controllerName,
                                string actionName,
                                object values, 
                                object htmlAttributes)

ASP.NET MVC2

two arguments have been switched around

Html.ActionLink(article.Title, 
                "Item",   // <-- ActionMethod
                "Login",  // <-- Controller Name.
                new { id = article.ArticleID }, // <-- Route arguments.
                null  // <-- htmlArguments .. which are none. You need this value
                      //     otherwise you call the WRONG method ...
                      //     (refer to comments, below).
                )

This uses the following method ActionLink signature:

public static string ActionLink(this HtmlHelper htmlHelper, 
                                string linkText,
                                string actionName,
                                string controllerName,
                                object values, 
                                object htmlAttributes)

ASP.NET MVC3+

arguments are in the same order as MVC2, however the id value is no longer required:

Html.ActionLink(article.Title, 
                "Item",   // <-- ActionMethod
                "Login",  // <-- Controller Name.
                new { article.ArticleID }, // <-- Route arguments.
                null  // <-- htmlArguments .. which are none. You need this value
                      //     otherwise you call the WRONG method ...
                      //     (refer to comments, below).
                )

This avoids hard-coding any routing logic into the link.

 <a href="/Item/Login/5">Title</a> 

This will give you the following html output, assuming:

1. article.Title = "Title"
2. article.ArticleID = 5
3. you still have the following route defined

. .

routes.MapRoute(
    "Default",     // Route name
    "{controller}/{action}/{id}",                           // URL with parameters
    new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
);

Answer 2

I wanted to add to Joseph Kingry's answer . He provided the solution but at first I couldn't get it to work either and got a result just like Adhip Gupta. And then I realized that the route has to exist in the first place and the parameters need to match the route exactly. So I had an id and then a text parameter for my route which also needed to be included too.

Html.ActionLink(article.Title, "Login", "Item", new { id = article.ArticleID, title = article.Title }, null)

Answer 3

您可能希望查看RouteLink()方法。您可以通过字典指定所有内容（链接文本和路由名称除外）。

Answer 4

I think that Joseph flipped controller and action. First comes the action then the controller. This is somewhat strange, but the way the signature looks.

Just to clarify things, this is the version that works (adaption of Joseph's example):

Html.ActionLink(article.Title, 
    "Login",  // <-- ActionMethod
    "Item",   // <-- Controller Name
    new { id = article.ArticleID }, // <-- Route arguments.
    null  // <-- htmlArguments .. which are none
    )

Answer 5

what about this

<%=Html.ActionLink("Get Involved", 
                   "Show", 
                   "Home", 
                   new 
                       { 
                           id = "GetInvolved" 
                       }, 
                   new { 
                           @class = "menuitem", 
                           id = "menu_getinvolved" 
                       }
                   )%>

Answer 6

Html.ActionLink(article.Title, "Login/" + article.ArticleID, 'Item") 

Answer 7

If you want to go all fancy-pants, here's how you can extend it to be able to do this:

@(Html.ActionLink<ArticlesController>(x => x.Details(), article.Title, new { id = article.ArticleID }))

You will need to put this in the System.Web.Mvc namespace:

public static class MyProjectExtensions
{
    public static MvcHtmlString ActionLink<TController>(this HtmlHelper htmlHelper, Expression<Action<TController>> expression, string linkText)
    {
        var urlHelper = new UrlHelper(htmlHelper.ViewContext.RequestContext, htmlHelper.RouteCollection);

        var link = new TagBuilder("a");

        string actionName = ExpressionHelper.GetExpressionText(expression);
        string controllerName = typeof(TController).Name.Replace("Controller", "");

        link.MergeAttribute("href", urlHelper.Action(actionName, controllerName));
        link.SetInnerText(linkText);

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

    public static MvcHtmlString ActionLink<TController, TAction>(this HtmlHelper htmlHelper, Expression<Action<TController, TAction>> expression, string linkText, object routeValues)
    {
        var urlHelper = new UrlHelper(htmlHelper.ViewContext.RequestContext, htmlHelper.RouteCollection);

        var link = new TagBuilder("a");

        string actionName = ExpressionHelper.GetExpressionText(expression);
        string controllerName = typeof(TController).Name.Replace("Controller", "");

        link.MergeAttribute("href", urlHelper.Action(actionName, controllerName, routeValues));
        link.SetInnerText(linkText);

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

    public static MvcHtmlString ActionLink<TController>(this HtmlHelper htmlHelper, Expression<Action<TController>> expression, string linkText, object routeValues, object htmlAttributes) where TController : Controller
    {
        var urlHelper = new UrlHelper(htmlHelper.ViewContext.RequestContext, htmlHelper.RouteCollection);

        var attributes = AnonymousObjectToKeyValue(htmlAttributes);

        var link = new TagBuilder("a");

        string actionName = ExpressionHelper.GetExpressionText(expression);
        string controllerName = typeof(TController).Name.Replace("Controller", "");

        link.MergeAttribute("href", urlHelper.Action(actionName, controllerName, routeValues));
        link.MergeAttributes(attributes, true);
        link.SetInnerText(linkText);

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

    private static Dictionary<string, object> AnonymousObjectToKeyValue(object anonymousObject)
    {
        var dictionary = new Dictionary<string, object>();

        if (anonymousObject == null) return dictionary;

        foreach (PropertyDescriptor propertyDescriptor in TypeDescriptor.GetProperties(anonymousObject))
        {
            dictionary.Add(propertyDescriptor.Name, propertyDescriptor.GetValue(anonymousObject));
        }

        return dictionary;
    }
}

This includes two overrides for Route Values and HTML Attributes , also, all of your views would need to add: @using YourProject.Controllers or you can add it to your web.config <pages><namespaces>

Answer 8

Use named parameters for readability and to avoid confusions.

@Html.ActionLink(
            linkText: "Click Here",
            actionName: "Action",
            controllerName: "Home",
            routeValues: new { Identity = 2577 },
            htmlAttributes: null)

Answer 9

With MVC5 i have done it like this and it is 100% working code....

@Html.ActionLink(department.Name, "Index", "Employee", new { 
                            departmentId = department.DepartmentID }, null)

You guys can get an idea from this...

Answer 10

This type use:

@Html.ActionLink("MainPage","Index","Home")

MainPage : Name of the text Index : Action View Home : HomeController

Base Use ActionLink

 <html> <head> <meta name="viewport" content="width=device-width" /> <title>_Layout</title> <link href="@Url.Content("~/Content/bootsrap.min.css")" rel="stylesheet" type="text/css" /> </head> <body> <div class="container"> <div class="col-md-12"> <button class="btn btn-default" type="submit">@Html.ActionLink("AnaSayfa","Index","Home")</button> <button class="btn btn-default" type="submit">@Html.ActionLink("Hakkımızda", "Hakkimizda", "Home")</button> <button class="btn btn-default" type="submit">@Html.ActionLink("Iletişim", "Iletisim", "Home")</button> </div> @RenderBody() <div class="col-md-12" style="height:200px;background-image:url(/img/footer.jpg)"> </div> </div> </body> </html>