我认为MVC和Web Api之间的区别有些混乱。简而言之，对于MVC，您可以使用登录表单并使用Cookie创建会话。对于Web
Api，没有会话。这就是为什么要使用令牌。

您不需要登录表单。令牌端点就是您所需要的。就像Win所描述的那样，您会将凭据发送到处理它的令牌端点。

这是一些获取令牌的客户端C＃代码：

    //using System;
    //using System.Collections.Generic;
    //using System.Net;
    //using System.Net.Http;
    //string token = GetToken("https://localhost:<port>/", userName, password);

    static string GetToken(string url, string userName, string password) {
        var pairs = new List<KeyValuePair<string, string>>
                    {
                        new KeyValuePair<string, string>( "grant_type", "password" ), 
                        new KeyValuePair<string, string>( "username", userName ), 
                        new KeyValuePair<string, string> ( "Password", password )
                    };
        var content = new FormUrlEncodedContent(pairs);
        ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
        using (var client = new HttpClient()) {
            var response = client.PostAsync(url + "Token", content).Result;
            return response.Content.ReadAsStringAsync().Result;
        }
    }

为了使用令牌，将其添加到请求的标头中：

    //using System;
    //using System.Collections.Generic;
    //using System.Net;
    //using System.Net.Http;
    //var result = CallApi("https://localhost:<port>/something", token);

    static string CallApi(string url, string token) {
        ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
        using (var client = new HttpClient()) {
            if (!string.IsNullOrWhiteSpace(token)) {
                var t = JsonConvert.DeserializeObject<Token>(token);

                client.DefaultRequestHeaders.Clear();
                client.DefaultRequestHeaders.Add("Authorization", "Bearer " + t.access_token);
            }
            var response = client.GetAsync(url).Result;
            return response.Content.ReadAsStringAsync().Result;
        }
    }

令牌在哪里：

//using Newtonsoft.Json;

class Token
{
    public string access_token { get; set; }
    public string token_type { get; set; }
    public int expires_in { get; set; }
    public string userName { get; set; }
    [JsonProperty(".issued")]
    public string issued { get; set; }
    [JsonProperty(".expires")]
    public string expires { get; set; }
}

现在在服务器端：

在Startup.Auth.cs中

        var oAuthOptions = new OAuthAuthorizationServerOptions
        {
            TokenEndpointPath = new PathString("/Token"),
            Provider = new ApplicationOAuthProvider("self"),
            AccessTokenExpireTimeSpan = TimeSpan.FromDays(14),
            // https
            AllowInsecureHttp = false
        };
        // Enable the application to use bearer tokens to authenticate users
        app.UseOAuthBearerTokens(oAuthOptions);

在ApplicationOAuthProvider.cs中，实际授予或拒绝访问的代码：

//using Microsoft.AspNet.Identity.Owin;
//using Microsoft.Owin.Security;
//using Microsoft.Owin.Security.OAuth;
//using System;
//using System.Collections.Generic;
//using System.Security.Claims;
//using System.Threading.Tasks;

public class ApplicationOAuthProvider : OAuthAuthorizationServerProvider
{
    private readonly string _publicClientId;

    public ApplicationOAuthProvider(string publicClientId)
    {
        if (publicClientId == null)
            throw new ArgumentNullException("publicClientId");

        _publicClientId = publicClientId;
    }

    public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
    {
        var userManager = context.OwinContext.GetUserManager<ApplicationUserManager>();

        var user = await userManager.FindAsync(context.UserName, context.Password);
        if (user == null)
        {
            context.SetError("invalid_grant", "The user name or password is incorrect.");
            return;
        }

        ClaimsIdentity oAuthIdentity = await user.GenerateUserIdentityAsync(userManager);
        var propertyDictionary = new Dictionary<string, string> { { "userName", user.UserName } };
        var properties = new AuthenticationProperties(propertyDictionary);

        AuthenticationTicket ticket = new AuthenticationTicket(oAuthIdentity, properties);
        // Token is validated.
        context.Validated(ticket);
    }

    public override Task TokenEndpoint(OAuthTokenEndpointContext context)
    {
        foreach (KeyValuePair<string, string> property in context.Properties.Dictionary)
        {
            context.AdditionalResponseParameters.Add(property.Key, property.Value);
        }
        return Task.FromResult<object>(null);
    }

    public override Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
    {
        // Resource owner password credentials does not provide a client ID.
        if (context.ClientId == null)
            context.Validated();

        return Task.FromResult<object>(null);
    }

    public override Task ValidateClientRedirectUri(OAuthValidateClientRedirectUriContext context)
    {
        if (context.ClientId == _publicClientId)
        {
            var expectedRootUri = new Uri(context.Request.Uri, "/");

            if (expectedRootUri.AbsoluteUri == context.RedirectUri)
                context.Validated();
        }
        return Task.FromResult<object>(null);
    }

}

如您所见，检索令牌没有涉及控制器。实际上，如果只需要Web
Api，则可以删除所有MVC引用。我简化了服务器端代码以使其更具可读性。您可以添加代码以升级安全性。

确保仅使用SSL。实现RequireHttpsAttribute以强制执行此操作。

您可以使用Authorize / AllowAnonymous属性来保护Web
Api。另外，您可以添加过滤器（例如RequireHttpsAttribute）以使您的Web Api更安全。我希望这有帮助。