Objective-C 上传图片至服务端

NSURL?*url?=?[NSURL?URLWithString: urlString ];

????
ASIFormDataRequest?*request?=?[ASIFormDataRequest?requestWithURL:url];
NSMutableData?*postData?=?[NSMutableData?dataWithContentsOfFile:imagePath];??
??
[request?setPostBodyFilePath:imagePath];

[request?setRequestMethod:@"POST"];
[request?startSynchronous];