问错误500 -获取下载drive.files.export

EN

- (void)downloadFile:(NSString *)fileID
         completionBlock:(void (^)(NSString *))onCompletionBlock
               failBlock:(void (^)(NSError *))onDownloadFailBlock {

    GTLRQuery *query = [GTLRDriveQuery_FilesExport queryForMediaWithFileId:fileID mimeType:@"application/pdf"];
    GTLRDriveService *service = self.driveService;

    [service executeQuery:query
          completionHandler:^(GTLRServiceTicket *callbackTicket,
                            GTLRDataObject *dataObject,
                            NSError *callbackError) {
            if (callbackError == nil) {
                // The file downloaded successfully; its data is available as dataObject.data
                // File has been downloaded 
            } else {
                if (onDownloadFailBlock) {
                    onDownloadFailBlock(callbackError);
                }
                return;
            }
    }];
}

Download drive.files.export

2017-03-30 22:37:50 +0000  elapsed: 29.406sec
Request: GET https://www.googleapis.com/drive/v3/files/[fileID]/export?alt=media&mimeType=application%2Fpdf
Request headers:
  Accept: application/json
  Authorization: Bearer _snip_
  Cache-Control: no-cache
  Content-Type: application/json; charset=utf-8
  User-Agent: org.cocoapods.GoogleAPIClientForREST/1.2.1 google-api-objc-client/3.0 iPhone/10.2 hw/sim (gzip)

Response: status 500
Response headers:
  Cache-Control: private, max-age=0
  Content-Encoding: gzip
  Content-Length: 123
  Content-Type: application/json; charset=UTF-8
  Date: Thu, 30 Mar 2017 22:37:50 GMT
  Expires: Thu, 30 Mar 2017 22:37:50 GMT
  Server: GSE
  Vary: Origin, X-Origin
  alt-svc: quic=":443"; ma=2592000; v="37,36,35"
  x-content-type-options: nosniff
  x-frame-options: SAMEORIGIN
  x-xss-protection: 1; mode=block

Response body: (180 bytes)
{
  "error" : {
    "message" : "Internal Error",
    "errors" : [
      {
        "reason" : "internalError",
        "message" : "Internal Error",
        "domain" : "global"
      }
    ],
    "code" : 500
  }
}