typedef enum
{
NSURLErrorUnknown = -1,   // "無效的URL地址"
NSURLErrorCancelled = -999,  // "無效的URL地址"
NSURLErrorBadURL = -1000,  // "無效的URL地址"
NSURLErrorTimedOut = -1001,  // "網(wǎng)絡不給力，請稍后再試"
NSURLErrorUnsupportedURL = -1002,  // "不支持的URL地址"
NSURLErrorCannotFindHost = -1003,  // "找不到服務器"
NSURLErrorCannotConnectToHost = -1004,  // "連接不上服務器"
NSURLErrorDataLengthExceedsMaximum = -1103,  // "請求數(shù)據(jù)長度超出最大限度"
NSURLErrorNetworkConnectionLost = -1005,  // "網(wǎng)絡連接異常"
NSURLErrorDNSLookupFailed = -1006,  // "DNS查詢失敗"
NSURLErrorHTTPTooManyRedirects = -1007,  // "HTTP請求重定向"
NSURLErrorResourceUnavailable = -1008,  // "資源不可用"
NSURLErrorNotConnectedToInternet = -1009,  // "無網(wǎng)絡連接"
NSURLErrorRedirectToNonExistentLocation = -1010,  // "重定向到不存在的位置"
NSURLErrorBadServerResponse = -1011,  // "服務器響應異常"
NSURLErrorUserCancelledAuthentication = -1012,  // "用戶取消授權(quán)"
NSURLErrorUserAuthenticationRequired = -1013,  // "需要用戶授權(quán)"
NSURLErrorZeroByteResource = -1014,  // "零字節(jié)資源"
NSURLErrorCannotDecodeRawData = -1015,  // "無法解碼原始數(shù)據(jù)"
NSURLErrorCannotDecodeContentData = -1016,  // "無法解碼內(nèi)容數(shù)據(jù)"
NSURLErrorCannotParseResponse = -1017,  // "無法解析響應"
NSURLErrorInternationalRoamingOff = -1018, // "國際漫游關閉"
NSURLErrorCallIsActive = -1019, // "被叫激活"
NSURLErrorDataNotAllowed = -1020, // "數(shù)據(jù)不被允許"
NSURLErrorRequestBodyStreamExhausted = -1021, // "請求體"
NSURLErrorFileDoesNotExist = -1100,  // "文件不存在"
NSURLErrorFileIsDirectory = -1101,  // "文件是個目錄"
NSURLErrorNoPermissionsToReadFile = -1102,  // "無讀取文件權(quán)限"
NSURLErrorSecureConnectionFailed = -1200,  // "安全連接失敗"
NSURLErrorServerCertificateHasBadDate = -1201,  // "服務器證書失效"
NSURLErrorServerCertificateUntrusted = -1202, // "不被信任的服務器證書"
NSURLErrorServerCertificateHasUnknownRoot = -1203,  // "未知Root的服務器證書"
NSURLErrorServerCertificateNotYetValid = -1204,  // "服務器證書未生效"
NSURLErrorClientCertificateRejected = -1205,  // "客戶端證書被拒"
NSURLErrorClientCertificateRequired = -1206,  // "需要客戶端證書"
NSURLErrorCannotLoadFromNetwork = -2000,  // "無法從網(wǎng)絡獲取"
NSURLErrorCannotCreateFile = -3000,  // "無法創(chuàng)建文件"
NSURLErrorCannotOpenFile = -3001,  // "無法打開文件"
NSURLErrorCannotCloseFile = -3002,  // "無法關閉文件"
NSURLErrorCannotWriteToFile = -3003,  // "無法寫入文件"
NSURLErrorCannotRemoveFile = -3004, // "無法刪除文件"
NSURLErrorCannotMoveFile = -3005,  // "無法移動文件"
NSURLErrorDownloadDecodingFailedMidStream = -3006,  // "下載解碼數(shù)據(jù)失敗"
NSURLErrorDownloadDecodingFailedToComplete = -3007  // "下載解碼數(shù)據(jù)失敗"
}