我采用了@LachlanB方法，当请求上有会话cookie时，会话确实是可用的。缺失的部分是会话cookie是如何第一次发送到客户端?

我创建了一个HttpModule，它不仅启用httpessionstate可用性，而且还在创建新会话时向客户端发送cookie。

public class WebApiSessionModule : IHttpModule
{
    private static readonly string SessionStateCookieName = "ASP.NET_SessionId";

    public void Init(HttpApplication context)
    {
        context.PostAuthorizeRequest += this.OnPostAuthorizeRequest;
        context.PostRequestHandlerExecute += this.PostRequestHandlerExecute;
    }

    public void Dispose()
    {
    }

    protected virtual void OnPostAuthorizeRequest(object sender, EventArgs e)
    {
        HttpContext context = HttpContext.Current;

        if (this.IsWebApiRequest(context))
        {
            context.SetSessionStateBehavior(SessionStateBehavior.Required);
        }
    }

    protected virtual void PostRequestHandlerExecute(object sender, EventArgs e)
    {
        HttpContext context = HttpContext.Current;

        if (this.IsWebApiRequest(context))
        {
            this.AddSessionCookieToResponseIfNeeded(context);
        }
    }

    protected virtual void AddSessionCookieToResponseIfNeeded(HttpContext context)
    {
        HttpSessionState session = context.Session;

        if (session == null)
        {
            // session not available
            return;
        }

        if (!session.IsNewSession)
        {
            // it's safe to assume that the cookie was
            // received as part of the request so there is
            // no need to set it
            return;
        }

        string cookieName = GetSessionCookieName();
        HttpCookie cookie = context.Response.Cookies[cookieName];
        if (cookie == null || cookie.Value != session.SessionID)
        {
            context.Response.Cookies.Remove(cookieName);
            context.Response.Cookies.Add(new HttpCookie(cookieName, session.SessionID));
        }
    }

    protected virtual string GetSessionCookieName()
    {
        var sessionStateSection = (SessionStateSection)ConfigurationManager.GetSection("system.web/sessionState");

        return sessionStateSection != null && !string.IsNullOrWhiteSpace(sessionStateSection.CookieName) ? sessionStateSection.CookieName : SessionStateCookieName;
    }

    protected virtual bool IsWebApiRequest(HttpContext context)
    {
        string requestPath = context.Request.AppRelativeCurrentExecutionFilePath;

        if (requestPath == null)
        {
            return false;
        }

        return requestPath.StartsWith(WebApiConfig.UrlPrefixRelative, StringComparison.InvariantCultureIgnoreCase);
    }
}

你说得对，REST是无状态的。如果您使用会话，处理将变成有状态的，后续请求将能够使用状态(来自会话)。

为了给会话补水，您需要提供一个键来关联状态。在普通的asp.net应用程序中，该密钥是通过使用cookie (cookie-sessions)或url参数(无cookie会话)来提供的。

如果你需要一个会话而不是休息，那么会话在基于rest的设计中是无关紧要的。如果您需要一个会话进行验证，则使用令牌或通过IP地址授权。

@LachlanB的回答中有一件事需要提一下。

protected void Application_PostAuthorizeRequest()
    {
        if (IsWebApiRequest())
        {
            HttpContext.Current.SetSessionStateBehavior(SessionStateBehavior.Required);
        }
    }

如果省略了If (IsWebApiRequest())

如果你的网站混合了网页表单，整个网站都会有页面加载缓慢的问题。

Mark，如果你检查nerddinner MVC示例，逻辑几乎是一样的。

您只需要检索cookie并在当前会话中设置它。

Global.asax.cs

public override void Init()
{
    this.AuthenticateRequest += new EventHandler(WebApiApplication_AuthenticateRequest);
    base.Init();
}

void WebApiApplication_AuthenticateRequest(object sender, EventArgs e)
{
    HttpCookie cookie = HttpContext.Current.Request.Cookies[FormsAuthentication.FormsCookieName];
    FormsAuthenticationTicket ticket = FormsAuthentication.Decrypt(cookie.Value);

    SampleIdentity id = new SampleIdentity(ticket);
    GenericPrincipal prin = new GenericPrincipal(id, null); 

    HttpContext.Current.User = prin;
}

enter code here

您必须定义“SampleIdentity”类，可以从nerddinner项目中借用这个类。

要解决这个问题:

protected void Application_PostAuthorizeRequest()
{
    System.Web.HttpContext.Current.SetSessionStateBehavior(System.Web.SessionState.SessionStateBehavior.Required);
}

在Global.asax.cs

回到基础，为什么不保持它的简单和存储会话值在一个隐藏的html值传递给你的API?

控制器

public ActionResult Index()
        {

            Session["Blah"] = 609;

            YourObject yourObject = new YourObject();
            yourObject.SessionValue = int.Parse(Session["Blah"].ToString());

            return View(yourObject);
        }

cshtml

@model YourObject

@{
    var sessionValue = Model.SessionValue;
}

<input type="hidden" value="@sessionValue" id="hBlah" />

Javascript

$(文件)。准备(函数(){

    var sessionValue = $('#hBlah').val();

    alert(sessionValue);

    /* Now call your API with the session variable */}

}