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我正在創建一個web-api，我需要登錄人們使用Facebook。重定向過多 - Owin外部登錄Facebook Asp.Net
我跟隨this guide。
一旦我向Facebook提供我的憑據，它應該重定向到一個操作，但它會說：「太多的重定向。」 
這是我在Startup.cs得：
app.UseExternalSignInCookie(Microsoft.AspNet.Identity.DefaultAuthenticationTypes.ExternalCookie);
FacebookAuthenticationOptions facebookAuthOptions = new FacebookAuthenticationOptions()
{
AppId = "myAppId",
AppSecret = "myAppKey",
Provider = new FacebookAuthProvider()
};
app.UseFacebookAuthentication(facebookAuthOptions);
這是我FacebookAuthProvider：類：
public class FacebookAuthProvider : FacebookAuthenticationProvider
{
public override Task Authenticated(FacebookAuthenticatedContext context)
{
context.Identity.AddClaim(new System.Security.Claims.Claim("ExternalAccessToken", context.AccessToken));
return Task.FromResult<object>(null);
}
}
這是我ChallengeResult等級：
public class ChallengeResult : IHttpActionResult
{
public string LoginProvider { get; set; }
public HttpRequestMessage Request { get; set; }
public ChallengeResult(string loginProvider, ApiController controller)
{
LoginProvider = loginProvider;
Request = controller.Request;
}
public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
{
Request.GetOwinContext().Authentication.Challenge(LoginProvider);
HttpResponseMessage response = new HttpResponseMessage(System.Net.HttpStatusCode.Unauthorized);
response.RequestMessage = Request;
return Task.FromResult<HttpResponseMessage>(response);
}
}
這是我用來獲取來自Facebook的令牌在用戶登錄後的控制器：
[HttpGet]
[OverrideAuthentication]
[HostAuthentication(DefaultAuthenticationTypes.ExternalCookie)]
[AllowAnonymous]
//[Route("ExternalLogin", Name = "ExternalLogin")]
public IHttpActionResult GetExternalLogin(string provider)
{
string redirectUri = string.Empty;
AppUserManager manager = new AppUserManager(new AppUserStore(new AppContext()));
if (!User.Identity.IsAuthenticated)
{
return new ChallengeResult(provider, this);
}
ExternalLoginData externalLogin = ExternalLoginData.FromIdentity(User.Identity as ClaimsIdentity);
UserLoginInfo loginInfo = new UserLoginInfo(externalLogin.LoginProvider, externalLogin.ProviderKey);
IdentityUser user = manager.Find(loginInfo);
bool hasRegistered = user != null;
ValidateRedirectUri(this.Request, ref redirectUri);
redirectUri = String.Format("{0}#external_access_token={1}&provider={2}&haslocalaccount={3}&external_user_name={4}",
redirectUri,
externalLogin.AccessToken,
externalLogin.LoginProvider,
hasRegistered.ToString(),
externalLogin.UserName);
return Redirect(redirectUri);
}
一兩件事，我真的很好奇，是，如果我取消這個行：
[Route("ExternalLogin", Name = "ExternalLogin")]
，然後嘗試使用新的路由訪問控制，它說，User（在GetExternalLogin的，當一）是null。
這是我用來測試的鏈接： http://localhost:62887/api/ExternalAuth/GetExternalLogin?provider=Facebook&redirect_uri=http://localhost:62887/api/ExternalAuth/LoggedIn
並且在用戶成功登錄，這是他應該被重定向動作：
[HttpGet]
public IHttpActionResult LoggedIn()
{
return Ok(new { Message = "You've been successfully logged in! :)" });
}