NSURLSessionUploadTask 上传

-(void)uploadPhotoImageWithUrl:(NSString*)url
                      userIMID:(NSString*)userIMID
                     imageData:(NSData*)imageData
                     imageName:(NSString*)imageName{
    
    NSString *TWITTERFON_FORM_BOUNDARY = @"AaB03x";
    
    //根据url初始化request
    NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:url]
                                                           cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
                                                       timeoutInterval:10];
    
    //分界线 --AaB03x
    NSString *MPboundary=[[NSString alloc]initWithFormat:@"--%@",TWITTERFON_FORM_BOUNDARY];
    //结束符 AaB03x--
    NSString *endMPboundary=[[NSString alloc]initWithFormat:@"%@--",MPboundary];
    
 
    //http body的字符串
    NSMutableString *body=[[NSMutableString alloc]init];
    //参数的集合的所有key的集合
    
    if(imageData){
        添加分界线，换行
        [body appendFormat:@"%@\r\n",MPboundary];
        
        //声明pic字段，文件名为boris.png
        [body appendFormat:@"Content-Disposition: form-data; name="%@"; filename="%@"\r\n",userIMID,imageName];
        //声明上传文件的格式
        [body appendFormat:@"Content-Type: image/jpge,image/gif, image/jpeg, image/pjpeg, image/pjpeg\r\n\r\n"];
    }
    
    //声明结束符：--AaB03x--
    NSString *end=[[NSString alloc]initWithFormat:@"\r\n%@",endMPboundary];
    //声明myRequestData，用来放入http body
    NSMutableData *myRequestData=[NSMutableData data];
    
    //将body字符串转化为UTF8格式的二进制
    [myRequestData appendData:[body dataUsingEncoding:NSUTF8StringEncoding]];
    if(imageData){
        //将image的data加入
        [myRequestData appendData:imageData];
    }
    //加入结束符--AaB03x--
    [myRequestData appendData:[end dataUsingEncoding:NSUTF8StringEncoding]];
    
    //设置HTTPHeader中Content-Type的值
    NSString *content=[[NSString alloc]initWithFormat:@"multipart/form-data; boundary=%@",TWITTERFON_FORM_BOUNDARY];
    //设置HTTPHeader
    [request setValue:content
   forHTTPHeaderField:@"Content-Type"];
    
    //设置Content-Length
    [request setValue:[NSString stringWithFormat:@"%ld", (unsigned long)[myRequestData length]]
   forHTTPHeaderField:@"Content-Length"];
    
    //设置http body
    [request setHTTPBody:myRequestData];
    
    //http method
    [request setHTTPMethod:@"POST"];
    
    
    // URLSession
    NSURLSession *session = [NSURLSession sharedSession];
    // 上传任务
    NSURLSessionUploadTask *task = [session uploadTaskWithRequest:request
                                                         fromData:myRequestData
                                                completionHandler:^(NSData *data, NSURLResponse *response, NSError *error)
                                    {
                                        
                                        if (!data) {
                                            NSString *result = [[NSString alloc] initWithData:data
                                                                                     encoding:NSUTF8StringEncoding];
                                            NSLog(@"%@ %@", result, response);
                                        } else {
                                            NSString *result = [[NSString alloc] initWithData:data
                                                                                     encoding:NSUTF8StringEncoding];
                                            NSLog(@"upload ok!  %@ ", result);
                                        }
                                    }];
    
    [task resume];


}