iOS7：将图像发布到服务器会导致错误HTTP状态406

Question

当我尝试将图片发布到服务器时，我收到错误

“此请求标识的资源只能根据请求”accept“headers（）生成具有不可接受特征的响应。”

以下是我用来上传图片的代码

 NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
 UIImage *image = [UIImage imageNamed:@"backGb.png"];
 [request setHTTPMethod:@"POST"];
 NSMutableData *bodyData = [[NSMutableData alloc] init];// backGb.jpg
 [bodyData appendData:[@"pic" dataUsingEncoding:NSUTF8StringEncoding]];
 [bodyData appendData:UIImagePNGRepresentation((UIImage *)image)];
 [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"content-type"];
  [request setValue:@"application/xml" forHTTPHeaderField:@"Accept"];
 [request setHTTPBody:bodyData];
 connection = [NSURLConnection connectionWithRequest:request delegate:self];

服务器团队要求我使用“使用文件作为参数'pic'”

我感谢任何帮助。