NSError详解

NSError Codes

NSError codes in the Cocoa error domain.

enum {   NSFileNoSuchFileError = 4,   NSFileLockingError = 255,   NSFileReadUnknownError = 256,   NSFileReadNoPermissionError = 257,   NSFileReadInvalidFileNameError = 258,   NSFileReadCorruptFileError = 259,   NSFileReadNoSuchFileError = 260,   NSFileReadInapplicableStringEncodingError = 261,   NSFileReadUnsupportedSchemeError = 262,   NSFileReadTooLargeError = 263,   NSFileReadUnknownStringEncodingError = 264,   NSFileWriteUnknownError = 512,   NSFileWriteNoPermissionError = 513,   NSFileWriteInvalidFileNameError = 514,   NSFileWriteFileExistsError = 516,   NSFileWriteInapplicableStringEncodingError = 517,   NSFileWriteUnsupportedSchemeError = 518,   NSFileWriteOutOfSpaceError = 640,   NSFileWriteVolumeReadOnlyError = 642,   NSKeyValueValidationError = 1024,   NSFormattingError = 2048,   NSUserCancelledError = 3072,      NSFileErrorMinimum = 0,   NSFileErrorMaximum = 1023,   NSValidationErrorMinimum = 1024,   NSValidationErrorMaximum = 2047,   NSFormattingErrorMinimum = 2048,   NSFormattingErrorMaximum = 2559,      NSPropertyListReadCorruptError = 3840,   NSPropertyListReadUnknownVersionError = 3841,   NSPropertyListReadStreamError = 3842,   NSPropertyListWriteStreamError = 3851,   NSPropertyListErrorMinimum = 3840,   NSPropertyListErrorMaximum = 4095      NSExecutableErrorMinimum = 3584,   NSExecutableNotLoadableError = 3584,   NSExecutableArchitectureMismatchError = 3585,   NSExecutableRuntimeMismatchError = 3586,   NSExecutableLoadError = 3587,   NSExecutableLinkError = 3588,   NSExecutableErrorMaximum = 3839,   }

Constants

NSFileNoSuchFileError

File-system operation attempted on non-existent file

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileLockingError

Failure to get a lock on file

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileReadUnknownError

Read error, reason unknown

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileReadNoPermissionError

Read error because of a permission problem

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileReadInvalidFileNameError

Read error because of an invalid file name

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileReadCorruptFileError

Read error because of a corrupted file, bad format, or similar reason

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileReadNoSuchFileError

Read error because no such file was found

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileReadInapplicableStringEncodingError

Read error because the string encoding was not applicable.

Access the bad encoding from the userInfo dictionary using the NSStringEncodingErrorKey key.

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileReadUnsupportedSchemeError

Read error because the specified URL scheme is unsupported

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileReadTooLargeError

Read error because the specified file was too large.

Available in OS X v10.5 and later.

Declared in FoundationErrors.h.

NSFileReadUnknownStringEncodingError

Read error because the string coding of the file could not be determined

Available in OS X v10.5 and later.

Declared in FoundationErrors.h.

NSFileWriteUnknownError

Write error, reason unknown

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileWriteNoPermissionError

Write error because of a permission problem

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileWriteInvalidFileNameError

Write error because of an invalid file name

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileWriteFileExistsError

Write error returned when NSFileManager class’s copy, move, and link methods report errors when the destination file already exists.

Available in OS X v10.7 and later.

Declared in FoundationErrors.h.

NSFileWriteInapplicableStringEncodingError

Write error because the string encoding was not applicable.

Access the bad encoding from the userInfo dictionary using the NSStringEncodingErrorKey key.

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileWriteUnsupportedSchemeError

Write error because the specified URL scheme is unsupported

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileWriteOutOfSpaceError

Write error because of a lack of disk space

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileWriteVolumeReadOnlyError

Write error because because the volume is read only.

Available in OS X v10.6 and later.

Declared in FoundationErrors.h.

NSKeyValueValidationError

Key-value coding validation error

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFormattingError

Formatting error (related to display of data)

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSUserCancelledError

The user cancelled the operation (for example, by pressing Command-period).

This code is for errors that do not require a dialog displayed and might be candidates for special-casing.

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileErrorMinimum

Marks the start of the range of error codes reserved for file errors

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFileErrorMaximum

Marks the end of the range of error codes reserved for file errors

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSValidationErrorMinimum

Marks the start of the range of error codes reserved for validation errors.

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSValidationErrorMaximum

Marks the start and end of the range of error codes reserved for validation errors.

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFormattingErrorMinimum

Marks the start of the range of error codes reserved for formatting errors.

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSFormattingErrorMaximum

Marks end of the range of error codes reserved for formatting errors.

Available in OS X v10.4 and later.

Declared in FoundationErrors.h.

NSPropertyListReadCorruptError

An error was encountered while parsing the property list.

Available in OS X v10.6 and later.

Declared in FoundationErrors.h.

NSPropertyListReadUnknownVersionError

The version number of the property list is unable to be determined.

Available in OS X v10.6 and later.

Declared in FoundationErrors.h.

NSPropertyListReadStreamError

An stream error was encountered while reading the property list.

Available in OS X v10.6 and later.

Declared in FoundationErrors.h.

NSPropertyListWriteStreamError

An stream error was encountered while writing the property list.

Available in OS X v10.6 and later.

Declared in FoundationErrors.h.

NSPropertyListErrorMinimum

Marks beginning of the range of error codes reserved for property list errors.

Available in OS X v10.6 and later.

Declared in FoundationErrors.h.

NSPropertyListErrorMaximum

Marks end of the range of error codes reserved for property list errors.

Available in OS X v10.6 and later.

Declared in FoundationErrors.h.

NSExecutableErrorMinimum

Marks beginning of the range of error codes reserved for errors related to executable files.

Available in OS X v10.5 and later.

Declared in FoundationErrors.h.

NSExecutableNotLoadableError

Executable is of a type that is not loadable in the current process.

Available in OS X v10.5 and later.

Declared in FoundationErrors.h.

NSExecutableArchitectureMismatchError

Executable does not provide an architecture compatible with the current process.

Available in OS X v10.5 and later.

Declared in FoundationErrors.h.

NSExecutableRuntimeMismatchError

Executable has Objective C runtime information incompatible with the current process.

Available in OS X v10.5 and later.

Declared in FoundationErrors.h.

NSExecutableLoadError

Executable cannot be loaded for some other reason, such as a problem with a library it depends on.

Available in OS X v10.5 and later.

Declared in FoundationErrors.h.

NSExecutableLinkError

Executable fails due to linking issues.

Available in OS X v10.5 and later.

Declared in FoundationErrors.h.

NSExecutableErrorMaximum

Marks end of the range of error codes reserved for errors related to executable files.

Available in OS X v10.5 and later.

Declared in FoundationErrors.h.

Discussion

The constants in this enumeration are NSError code numbers in the Cocoa error domain (NSCocoaErrorDomain). Other frameworks, most notably the Application Kit, provide their own NSCocoaErrorDomain error codes.

The enumeration constants beginning with NSFile indicate file-system errors or errors related to file I/O operations. Use the key NSFilePathErrorKey or the NSURLErrorKey(whichever is appropriate) to access the file-system path or URL in the userInfo dictionary of the NSError object.

Declared In

FoundationErrors.h

URL Loading System Error Codes

These values are returned as the error code property of an NSError object with the domain “NSURLErrorDomain”.

enum{   NSURLErrorUnknown = -1,   NSURLErrorCancelled = -999,   NSURLErrorBadURL = -1000,   NSURLErrorTimedOut = -1001,   NSURLErrorUnsupportedURL = -1002,   NSURLErrorCannotFindHost = -1003,   NSURLErrorCannotConnectToHost = -1004,   NSURLErrorDataLengthExceedsMaximum = -1103,   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,   NSURLErrorInternationalRoamingOff = -1018,   NSURLErrorCallIsActive = -1019,   NSURLErrorDataNotAllowed = -1020,   NSURLErrorRequestBodyStreamExhausted = -1021,   NSURLErrorFileDoesNotExist = -1100,   NSURLErrorFileIsDirectory = -1101,   NSURLErrorNoPermissionsToReadFile = -1102,   NSURLErrorSecureConnectionFailed = -1200,   NSURLErrorServerCertificateHasBadDate = -1201,   NSURLErrorServerCertificateUntrusted = -1202,   NSURLErrorServerCertificateHasUnknownRoot = -1203,   NSURLErrorServerCertificateNotYetValid = -1204,   NSURLErrorClientCertificateRejected = -1205,   NSURLErrorClientCertificateRequired = -1206,   NSURLErrorCannotLoadFromNetwork = -2000,   NSURLErrorCannotCreateFile = -3000,   NSURLErrorCannotOpenFile = -3001,   NSURLErrorCannotCloseFile = -3002,   NSURLErrorCannotWriteToFile = -3003,   NSURLErrorCannotRemoveFile = -3004,   NSURLErrorCannotMoveFile = -3005,   NSURLErrorDownloadDecodingFailedMidStream = -3006,   NSURLErrorDownloadDecodingFailedToComplete = -3007}

Constants

NSURLErrorUnknown

Returned when the URL Loading system encounters an error that it cannot interpret.

This can occur when an error originates from a lower level framework or library. Whenever this error code is received, it is a bug, and should be reported to Apple.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorCancelled

Returned when an asynchronous load is canceled.

A Web Kit framework delegate will receive this error when it performs a cancel operation on a loading resource. Note that an NSURLConnection or NSURLDownload delegate will not receive this error if the download is canceled.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorBadURL

Returned when a URL is sufficiently malformed that a URL request cannot be initiated

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorTimedOut

Returned when an asynchronous operation times out.

NSURLConnection will send this error to its delegate when the timeoutInterval in NSURLRequest expires before a load can complete.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorUnsupportedURL

Returned when a properly formed URL cannot be handled by the framework.

The most likely cause is that there is no available protocol handler for the URL.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorCannotFindHost

Returned when the host name for a URL cannot be resolved.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorCannotConnectToHost

Returned when an attempt to connect to a host has failed.

This can occur when a host name resolves, but the host is down or may not be accepting connections on a certain port.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorDataLengthExceedsMaximum

Returned when the length of the resource data exceeds the maximum allowed.

Available in OS X v10.5 and later.

Declared in NSURLError.h.

NSURLErrorNetworkConnectionLost

Returned when a client or server connection is severed in the middle of an in-progress load.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorDNSLookupFailed

See NSURLErrorCannotFindHost

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorHTTPTooManyRedirects

Returned when a redirect loop is detected or when the threshold for number of allowable redirects has been exceeded (currently 16).

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorResourceUnavailable

Returned when a requested resource cannot be retrieved.

Examples are “file not found”, and data decoding problems that prevent data from being processed correctly.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorNotConnectedToInternet

Returned when a network resource was requested, but an internet connection is not established and cannot be established automatically, either through a lack of connectivity, or by the user's choice not to make a network connection automatically.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorRedirectToNonExistentLocation

Returned when a redirect is specified by way of server response code, but the server does not accompany this code with a redirect URL.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorBadServerResponse

Returned when the URL Loading system receives bad data from the server.

This is equivalent to the “500 Server Error” message sent by HTTP servers.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorUserCancelledAuthentication

Returned when an asynchronous request for authentication is cancelled by the user.

This is typically incurred by clicking a “Cancel” button in a username/password dialog, rather than the user making an attempt to authenticate.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorUserAuthenticationRequired

Returned when authentication is required to access a resource.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorZeroByteResource

Returned when a server reports that a URL has a non-zero content length, but terminates the network connection “gracefully” without sending any data.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorCannotDecodeRawData

Returned when content data received during an NSURLConnection request cannot be decoded for a known content encoding.

Available in OS X v10.5 and later.

Declared in NSURLError.h.

NSURLErrorCannotDecodeContentData

Returned when content data received during an NSURLConnection request has an unknown content encoding.

Available in OS X v10.5 and later.

Declared in NSURLError.h.

NSURLErrorCannotParseResponse

Returned when a response to an NSURLConnection request cannot be parsed.

Available in OS X v10.5 and later.

Declared in NSURLError.h.

NSURLErrorInternationalRoamingOff

Returned when a connection would require activating a data context while roaming, but international roaming is disabled.

Available in OS X v10.7 and later.

Declared in NSURLError.h.

NSURLErrorCallIsActive

Returned when a connection is attempted while a phone call is active on a network that does not support simultaneous phone and data communication (EDGE or GPRS).

Available in OS X v10.7 and later.

Declared in NSURLError.h.

NSURLErrorDataNotAllowed

Returned when the cellular network disallows a connection.

Available in OS X v10.7 and later.

Declared in NSURLError.h.

NSURLErrorRequestBodyStreamExhausted

Returned when a body stream is needed but the client does not provide one. This impacts clients on iOS that send a POST request using a body stream but do not implement the NSURLConnection delegate method connection:needNewBodyStream.

Available in OS X v10.7 and later.

Declared in NSURLError.h.

NSURLErrorFileDoesNotExist

Returned when a file does not exist.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorFileIsDirectory

Returned when a request for an FTP file results in the server responding that the file is not a plain file, but a directory.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorNoPermissionsToReadFile

Returned when a resource cannot be read due to insufficient permissions.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorSecureConnectionFailed

Returned when an attempt to establish a secure connection fails for reasons which cannot be expressed more specifically.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorServerCertificateHasBadDate

Returned when a server certificate has a date which indicates it has expired, or is not yet valid.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorServerCertificateUntrusted

Returned when a server certificate is signed by a root server which is not trusted.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorServerCertificateHasUnknownRoot

Returned when a server certificate is not signed by any root server.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorServerCertificateNotYetValid

Returned when a server certificate is not yet valid.

Available in OS X v10.4 and later.

Declared in NSURLError.h.

NSURLErrorClientCertificateRejected

Returned when a server certificate is rejected.

Available in OS X v10.4 and later.

Declared in NSURLError.h.

NSURLErrorClientCertificateRequired

Returned when a client certificate is required to authenticate an SSL connection during an NSURLConnection request.

Available in OS X v10.6 and later.

Declared in NSURLError.h.

NSURLErrorCannotLoadFromNetwork

Returned when a specific request to load an item only from the cache cannot be satisfied.

This error is sent at the point when the library would go to the network accept for the fact that is has been blocked from doing so by the “load only from cache” directive.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorCannotCreateFile

Returned when NSURLDownload object was unable to create the downloaded file on disk due to a I/O failure.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorCannotOpenFile

Returned when NSURLDownload was unable to open the downloaded file on disk.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorCannotCloseFile

Returned when NSURLDownload was unable to close the downloaded file on disk.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorCannotWriteToFile

Returned when NSURLDownload was unable to write to the downloaded file on disk.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorCannotRemoveFile

Returned when NSURLDownload was unable to remove a downloaded file from disk.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorCannotMoveFile

Returned when NSURLDownload was unable to move a downloaded file on disk.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorDownloadDecodingFailedMidStream

Returned when NSURLDownload failed to decode an encoded file during the download.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

NSURLErrorDownloadDecodingFailedToComplete

Returned when NSURLDownload failed to decode an encoded file after downloading.

Available in OS X v10.2 and later.

Declared in NSURLError.h.

Availability

• Available in OS X v10.2 with Safari 1.0 installed.
• Available in OS X v10.2.7 and later.

Declared In

NSURLError.h

iCloud Error Codes

These error codes are used by error objects associated with the NSURLUbiquitousItemDownloadingErrorKey on an NSURL object when an iCloud-related error occurs.

   NSUbiquitousFileErrorMinimum = 4352,   NSUbiquitousFileUnavailableError = 4353,   NSUbiquitousFileNotUploadedDueToQuotaError = 4354,   NSUbiquitousFileUbiquityServerNotAvailable = 4355,   NSUbiquitousFileErrorMaximum = 4607

Constants

NSUbiquitousFileErrorMinimum

The minimum error code value that represents an iCloud error.

Available in OS X v10.9 and later.

Declared in FoundationErrors.h.

NSUbiquitousFileUnavailableError

The item has not been uploaded to iCloud by another device yet.

When this error occurs, you do not need to ask the system to start downloading the item. The system will download the item as soon as it can. If you want to know when the item becomes available, use an NSMetadataQuery object to monitor changes to the file’s URL.

Available in OS X v10.9 and later.

Declared in FoundationErrors.h.

NSUbiquitousFileNotUploadedDueToQuotaError

The item could not be uploaded to iCloud because it would make the account go over its quota.

Available in OS X v10.9 and later.

Declared in FoundationErrors.h.

NSUbiquitousFileUbiquityServerNotAvailable

Connecting to the iCloud servers failed.

Available in OS X v10.9 and later.

Declared in FoundationErrors.h.

NSUbiquitousFileErrorMaximum

The maximum error code value that represents an iCloud error.

Available in OS X v10.9 and later.

Declared in FoundationErrors.h.

XPC Errors

Errors returned by XPC connections. Note that these are not currently available on iOS.

   NSXPCConnectionInterrupted = 4097,   NSXPCConnectionInvalid = 4099,   NSXPCConnectionReplyInvalid = 4101,   NSXPCConnectionErrorMinimum = 4096,   NSXPCConnectionErrorMaximum = 4224

Constants

NSXPCConnectionInterrupted

The XPC connection was interrupted.

Available in OS X v10.8 and later.

Declared in FoundationErrors.h.

NSXPCConnectionInvalid

The XPC connection was invalid.

Available in OS X v10.8 and later.

Declared in FoundationErrors.h.

NSXPCConnectionReplyInvalid

The XPC connection reply was invalid.

Available in OS X v10.8 and later.

Declared in FoundationErrors.h.

NSXPCConnectionErrorMinimum

The XPC connection minimum error.

Available in OS X v10.8 and later.

Declared in FoundationErrors.h.

NSXPCConnectionErrorMaximum

The XPC connection maximum error.

Available in OS X v10.8 and later.

Declared in FoundationErrors.h.