分享：XMLHTTPRequest的属性和方法简介

分享：XMLHTTPRequest的属性和方法简介(7)          // 400:Bad Request
         // 401:Unauthorized
         // 402:Payment Required
         // 403:Forbidden
         // 404:Not Found
         // 405:Method Not Allowed
         // 406:Not Acceptable
         // 407:Proxy Authentication Required
         // 408:Request Timeout
         // 409:Conflict
         // 410:Gone
         // 411:Length Required
         // 412:Precondition Failed
         // 413:Request Entity Too Large
         // 414:Request-URI Too Long
         // 415:Unsupported Media Type
         // 416:Requested Range Not Suitable
         // 417:EXPectation Failed
         // 500:Internal Server Error
         // 501:Not Implemented
         // 502:Bad Gateway
         // 503:Service Unavailable
         // 504:Gateway Timeout
         // 505:HTTP Version Not Supported
         // 备注：长整形，此属性只读，返回当前请求的http状态码,此属性仅当数据发送并接收完毕后才可获取。