enum : NSInteger {
    NSFileNoSuchFileError = 4, //无此类文件
    NSFileLockingError = 255, //文件锁定中
    NSFileReadUnknownError = 256, //读取未知文件
    NSFileReadNoPermissionError = 257, //读取无权限文件
    NSFileReadInvalidFileNameError = 258, //读取无效文件
    NSFileReadCorruptFileError = 259, //读取损坏文件
    NSFileReadNoSuchFileError = 260, //读取不存在文件
    NSFileReadInapplicableStringEncodingError = 261, //不合适的字符编码
    NSFileReadUnsupportedSchemeError = 262, //读取不支持的白名单
    NSFileReadTooLargeError = 263, //读取的文件啊太大
    NSFileReadUnknownStringEncodingError = 264, //读取了未知的字符编码
    NSFileWriteUnknownError = 512, //写入未知文件
    NSFileWriteNoPermissionError = 513, //读取无权限文件
    NSFileWriteInvalidFileNameError = 514, //读取无效文件
    NSFileWriteFileExistsError = 516, //写入不存在的文件
    NSFileWriteInapplicableStringEncodingError = 517, //不合适的字符编码
    NSFileWriteUnsupportedSchemeError = 518, //读取不支持的白名单
    NSFileWriteOutOfSpaceError = 640, //文件写出界
    NSFileWriteVolumeReadOnlyError = 642, //写,只读错误
    NSKeyValueValidationError = 1024, //键值验证错误
    NSFormattingError = 2048, //格式错误
    NSUserCancelledError = 3072, //用户已取消错误
    NSFeatureUnsupportedError = 3328, //功能不支持的错误
    NSExecutableNotLoadableError = 3584, //可执行文件不可加载错误
    NSExecutableArchitectureMismatchError = 3585, //可执行体系结构不匹配错误
    NSExecutableRuntimeMismatchError = 3586, //可执行运行时失配错误
    NSExecutableLoadError = 3587, //可执行加载错误
    NSExecutableLinkError = 3588, //可执行链接错误
    NSFileErrorMinimum = 0, 
    NSFileErrorMaximum = 1023,
    NSValidationErrorMinimum = 1024,
    NSValidationErrorMaximum = 2047,
    NSExecutableErrorMinimum = 3584,
    NSExecutableErrorMaximum = 3839,
    NSFormattingErrorMinimum = 2048,
    NSFormattingErrorMaximum = 2559,
    NSPropertyListReadCorruptError = 3840,
    NSPropertyListReadUnknownVersionError = 3841,
    NSPropertyListReadStreamError = 3842,
    NSPropertyListWriteStreamError = 3851,
    NSPropertyListWriteInvalidError = 3852,
    NSPropertyListErrorMinimum = 3840,
    NSPropertyListErrorMaximum = 4095,
    NSXPCConnectionInterrupted = 4097,
    NSXPCConnectionInvalid = 4099,
    NSXPCConnectionReplyInvalid = 4101,
    NSXPCConnectionErrorMinimum = 4096,
    NSXPCConnectionErrorMaximum = 4224,
    NSUbiquitousFileUnavailableError = 4353,
    NSUbiquitousFileNotUploadedDueToQuotaError = 4354,
    NSUbiquitousFileUbiquityServerNotAvailable = 4355,
    NSUbiquitousFileErrorMinimum = 4352,
    NSUbiquitousFileErrorMaximum = 4607,
    NSUserActivityHandoffFailedError = 4608,
    NSUserActivityConnectionUnavailableError = 4609,
    NSUserActivityRemoteApplicationTimedOutError = 4610,
    NSUserActivityHandoffUserInfoTooLargeError = 4611,
    NSUserActivityErrorMinimum = 4608,
    NSUserActivityErrorMaximum = 4863,
    NSCoderReadCorruptError = 4864,
    NSCoderValueNotFoundError = 4865,
    NSCoderErrorMinimum = 4864,
    NSCoderErrorMaximum = 4991,
    NSBundleErrorMinimum = 4992,
    NSBundleErrorMaximum = 5119,
    NSBundleOnDemandResourceOutOfSpaceError = 4992,
    NSBundleOnDemandResourceExceededMaximumSizeError = 4993,
    NSBundleOnDemandResourceInvalidTagError = 4994,
    NSCloudSharingNetworkFailureError = 5120,
    NSCloudSharingQuotaExceededError = 5121,
    NSCloudSharingTooManyParticipantsError = 5122,
    NSCloudSharingConflictError = 5123,
    NSCloudSharingNoPermissionError = 5124,
    NSCloudSharingOtherError = 5375,
    NSCloudSharingErrorMinimum = 5120,
    NSCloudSharingErrorMaximum = 5375
};