NSURLErrorDomain错误码说明

Question

这是我开发ios应用程序的第一次经验。我正在尝试使用Facebook图形api发布一些数据。我经常收到以下错误：

The operation couldn’t be completed. (NSURLErrorDomain error 400.)

我找不到NSURLErrorDomain错误代码的描述。400错误代码是什么意思？

Answer 1

https://developer.apple.com/documentation/foundation/1508628-url_loading_system_error_codes中列出了NSURLErrorDomain错误代码

然而，http 400只是返回的状态码(http://www.w3.org/Protocols/HTTP/HTRESP.html)，这意味着您的请求有问题。

Answer 2

在Swift中开发时，我找不到给定代码的错误名称。出于这个原因，我从NSURLError.h中为NSURLErrorDomain粘贴了减号代码

/*!
    @enum NSURL-related Error Codes
    @abstract Constants used by NSError to indicate errors in the NSURL domain
*/
NS_ENUM(NSInteger)
{
    NSURLErrorUnknown =             -1,
    NSURLErrorCancelled =           -999,
    NSURLErrorBadURL =              -1000,
    NSURLErrorTimedOut =            -1001,
    NSURLErrorUnsupportedURL =          -1002,
    NSURLErrorCannotFindHost =          -1003,
    NSURLErrorCannotConnectToHost =         -1004,
    NSURLErrorNetworkConnectionLost =       -1005,
    NSURLErrorDNSLookupFailed =         -1006,
    NSURLErrorHTTPTooManyRedirects =        -1007,
    NSURLErrorResourceUnavailable =         -1008,
    NSURLErrorNotConnectedToInternet =      -1009,
    NSURLErrorRedirectToNonExistentLocation =   -1010,
    NSURLErrorBadServerResponse =       -1011,
    NSURLErrorUserCancelledAuthentication =     -1012,
    NSURLErrorUserAuthenticationRequired =  -1013,
    NSURLErrorZeroByteResource =        -1014,
    NSURLErrorCannotDecodeRawData =             -1015,
    NSURLErrorCannotDecodeContentData =         -1016,
    NSURLErrorCannotParseResponse =             -1017,
    NSURLErrorAppTransportSecurityRequiresSecureConnection NS_ENUM_AVAILABLE(10_11, 9_0) = -1022,
    NSURLErrorFileDoesNotExist =        -1100,
    NSURLErrorFileIsDirectory =         -1101,
    NSURLErrorNoPermissionsToReadFile =     -1102,
    NSURLErrorDataLengthExceedsMaximum NS_ENUM_AVAILABLE(10_5, 2_0) =   -1103,

    // SSL errors
    NSURLErrorSecureConnectionFailed =      -1200,
    NSURLErrorServerCertificateHasBadDate =     -1201,
    NSURLErrorServerCertificateUntrusted =  -1202,
    NSURLErrorServerCertificateHasUnknownRoot = -1203,
    NSURLErrorServerCertificateNotYetValid =    -1204,
    NSURLErrorClientCertificateRejected =   -1205,
    NSURLErrorClientCertificateRequired =   -1206,
    NSURLErrorCannotLoadFromNetwork =       -2000,

    // Download and file I/O errors
    NSURLErrorCannotCreateFile =        -3000,
    NSURLErrorCannotOpenFile =          -3001,
    NSURLErrorCannotCloseFile =         -3002,
    NSURLErrorCannotWriteToFile =       -3003,
    NSURLErrorCannotRemoveFile =        -3004,
    NSURLErrorCannotMoveFile =          -3005,
    NSURLErrorDownloadDecodingFailedMidStream = -3006,
    NSURLErrorDownloadDecodingFailedToComplete =-3007,

    NSURLErrorInternationalRoamingOff NS_ENUM_AVAILABLE(10_7, 3_0) =         -1018,
    NSURLErrorCallIsActive NS_ENUM_AVAILABLE(10_7, 3_0) =                    -1019,
    NSURLErrorDataNotAllowed NS_ENUM_AVAILABLE(10_7, 3_0) =                  -1020,
    NSURLErrorRequestBodyStreamExhausted NS_ENUM_AVAILABLE(10_7, 3_0) =      -1021,

    NSURLErrorBackgroundSessionRequiresSharedContainer NS_ENUM_AVAILABLE(10_10, 8_0) = -995,
    NSURLErrorBackgroundSessionInUseByAnotherProcess NS_ENUM_AVAILABLE(10_10, 8_0) = -996,
    NSURLErrorBackgroundSessionWasDisconnected NS_ENUM_AVAILABLE(10_10, 8_0)= -997,
};

Answer 3

SWIFT 3中的以下是Swift 3枚举中的NSURLErrorDomain错误代码描述：(从上面的答案中复制，并尽可能进行转换)。

enum NSURLError: Int {
    case unknown = -1
    case cancelled = -999
    case badURL = -1000
    case timedOut = -1001
    case unsupportedURL = -1002
    case cannotFindHost = -1003
    case cannotConnectToHost = -1004
    case connectionLost = -1005
    case lookupFailed = -1006
    case HTTPTooManyRedirects = -1007
    case resourceUnavailable = -1008
    case notConnectedToInternet = -1009
    case redirectToNonExistentLocation = -1010
    case badServerResponse = -1011
    case userCancelledAuthentication = -1012
    case userAuthenticationRequired = -1013
    case zeroByteResource = -1014
    case cannotDecodeRawData = -1015
    case cannotDecodeContentData = -1016
    case cannotParseResponse = -1017
    //case NSURLErrorAppTransportSecurityRequiresSecureConnection NS_ENUM_AVAILABLE(10_11, 9_0) = -1022
    case fileDoesNotExist = -1100
    case fileIsDirectory = -1101
    case noPermissionsToReadFile = -1102
    //case NSURLErrorDataLengthExceedsMaximum NS_ENUM_AVAILABLE(10_5, 2_0) =   -1103

    // SSL errors
    case secureConnectionFailed = -1200
    case serverCertificateHasBadDate = -1201
    case serverCertificateUntrusted = -1202
    case serverCertificateHasUnknownRoot = -1203
    case serverCertificateNotYetValid = -1204
    case clientCertificateRejected = -1205
    case clientCertificateRequired = -1206
    case cannotLoadFromNetwork = -2000

    // Download and file I/O errors
    case cannotCreateFile = -3000
    case cannotOpenFile = -3001
    case cannotCloseFile = -3002
    case cannotWriteToFile = -3003
    case cannotRemoveFile = -3004
    case cannotMoveFile = -3005
    case downloadDecodingFailedMidStream = -3006
    case downloadDecodingFailedToComplete = -3007

    /*
     case NSURLErrorInternationalRoamingOff NS_ENUM_AVAILABLE(10_7, 3_0) =         -1018
     case NSURLErrorCallIsActive NS_ENUM_AVAILABLE(10_7, 3_0) =                    -1019
     case NSURLErrorDataNotAllowed NS_ENUM_AVAILABLE(10_7, 3_0) =                  -1020
     case NSURLErrorRequestBodyStreamExhausted NS_ENUM_AVAILABLE(10_7, 3_0) =      -1021

     case NSURLErrorBackgroundSessionRequiresSharedContainer NS_ENUM_AVAILABLE(10_10, 8_0) = -995
     case NSURLErrorBackgroundSessionInUseByAnotherProcess NS_ENUM_AVAILABLE(10_10, 8_0) = -996
     case NSURLErrorBackgroundSessionWasDisconnected NS_ENUM_AVAILABLE(10_10, 8_0)= -997
     */
}

直接链接到Swift github存储库中的URLError.Code，其中包含正在使用的错误代码(github link)的最新列表。