使用对象参数发布-iOS

我有一个iOS应用程序，它向包括Facebook在内的在线服务发出经过身份验证的POST请求。我的问题是我知道如何发布文本，但我不能发布图像。这是我的密码：

 NSData *imageData = UIImagePNGRepresentation(image_selected);
    NSString *postLength = [NSString stringWithFormat:@"%d", [imageData length]];

    // Init the URLRequest
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setHTTPMethod:@"POST"];

    NSString *facebook_picture_url = [NSString stringWithFormat:@"https://graph.facebook.com/ID/photos?message=%@&access_token=%@", inputted_text, token_facebook];
                    [request setURL:[NSURL URLWithString:facebook_picture_url]];
                    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
                    [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
                    [request setHTTPBody:imageData];
                    request.HTTPBody = imageData;
                    request.HTTPMethod = @"POST";


                    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
                    NSHTTPURLResponse *response = nil;
                    NSError *error = nil;
                    NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
                    NSLog(@"The responce:\n\n%@", response);

                    if (connection) {
                        // response data of the request
                    }

如您所见，我可以将“imageData”添加到HTTPBody中，但问题是一些服务希望将其作为某种参数。例如：Facebook希望它是：

source=“imagedata…”

另外，如果您查看URL，您将看到有一个“message=”参数。这一切都是可行的，但我肯定可以将其添加到HTTPBody中

我需要使用类似于词典的东西吗

谢谢你抽出时间，

---

Daniel

感谢开发者社区的帮助，哈哈。。。。无论如何，如果有人正在阅读本文，并且有兴趣知道如何将图像发布到Facebook等服务，我就是这样做的：

NSData *imageData = UIImagePNGRepresentation(image_selected);

NSString *facebook_picture_url = [NSString stringWithFormat:@"https://graph.facebook.com/USER_ID/photos?message=%@&access_token=%@", inputted_text, token_facebook];

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:facebook_picture_url]];
[request setHTTPMethod:@"POST"];

NSString *boundary = @"---------------------------14737809831466499882746641449";
NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
[request addValue:contentType forHTTPHeaderField:@"Content-Type"];

NSMutableData *body = [NSMutableData data];
[body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[@"Content-Disposition: form-data; name=\"userfile\"; filename=\".JPG\"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[@"Content-Type: application/octet-stream\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[NSData dataWithData:imageData]];
[body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[request setHTTPBody:body];

NSHTTPURLResponse *response = nil;
NSError *error = nil;
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
NSLog(@"The responce:\n\n%@", responseData);

if (error == nil && response.statusCode == 200) {
    NSLog(@"%li", (long)response.statusCode);
}

else {
  //Error handling
  NSLog(@"%@", response);
}