AFNetworking:AFHTTPSessionManager:POST调用了两次

如果您收到身份验证挑战,您将看到第二个请求。

如果需要,您可以简单地拒绝授权质询,这将停止第二个请求:

[manager setTaskDidReceiveAuthenticationChallengeBlock:^NSURLSessionAuthChallengeDisposition(NSURLSession * _Nonnull session, NSURLSessionTask * _Nonnull task, NSURLAuthenticationChallenge * _Nonnull challenge, NSURLCredential *__autoreleasing  _Nullable * _Nullable credential) {
    return NSURLSessionAuthChallengeCancelAuthenticationChallenge;
}];

或者,如果您想继续进行身份验证,可以执行以下操作:

[manager setTaskDidReceiveAuthenticationChallengeBlock:^NSURLSessionAuthChallengeDisposition(NSURLSession * _Nonnull session, NSURLSessionTask * _Nonnull task, NSURLAuthenticationChallenge * _Nonnull challenge, NSURLCredential *__autoreleasing  _Nullable * _Nullable credential) {
    if (challenge.previousFailureCount == 0) {
        *credential = [NSURLCredential credentialWithUser:self.user password:self.password persistence:NSURLCredentialPersistenceForSession];
        return NSURLSessionAuthChallengeUseCredential;
    }

    return NSURLSessionAuthChallengeCancelAuthenticationChallenge;
}];

这完全取决于您如何验证web服务上的用户。