POST multipart/form-data with Objective-C| 同时上传多张图片和参数的方式 Objective-C/Swift

post_form_data.m

- (NSData *)createBodyWithBoundary:(NSString *)boundary
                        parameters:(NSDictionary *)parameters
                             paths:(NSArray *)paths
                         fieldName:(NSString *)fieldName {
    NSMutableData *httpBody = [NSMutableData data];

    // add params (all params are strings)

    [parameters enumerateKeysAndObjectsUsingBlock:^(NSString *parameterKey, NSString *parameterValue, BOOL *stop) {
        [httpBody appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
        [httpBody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n", parameterKey] dataUsingEncoding:NSUTF8StringEncoding]];
        [httpBody appendData:[[NSString stringWithFormat:@"%@\r\n", parameterValue] dataUsingEncoding:NSUTF8StringEncoding]];
    }];

    // add image data

    for (NSString *path in paths) {
        NSString *filename  = [path lastPathComponent];
        NSData   *data      = [NSData dataWithContentsOfFile:path];
        NSString *mimetype  = [self mimeTypeForPath:path];

        [httpBody appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
        [httpBody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"%@\"\r\n", fieldName, filename] dataUsingEncoding:NSUTF8StringEncoding]];
        [httpBody appendData:[[NSString stringWithFormat:@"Content-Type: %@\r\n\r\n", mimetype] dataUsingEncoding:NSUTF8StringEncoding]];
        [httpBody appendData:data];
        [httpBody appendData:[@"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
    }

    [httpBody appendData:[[NSString stringWithFormat:@"--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];

    return httpBody;
}
@import MobileCoreServices;    // only needed in iOS

- (NSString *)mimeTypeForPath:(NSString *)path {
    // get a mime type for an extension using MobileCoreServices.framework

    CFStringRef extension = (__bridge CFStringRef)[path pathExtension];
    CFStringRef UTI = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, extension, NULL);
    assert(UTI != NULL);

    NSString *mimetype = CFBridgingRelease(UTTypeCopyPreferredTagWithClass(UTI, kUTTagClassMIMEType));
    assert(mimetype != NULL);

    CFRelease(UTI);

    return mimetype;
}

- (NSString *)generateBoundaryString {
    return [NSString stringWithFormat:@"Boundary-%@", [[NSUUID UUID] UUIDString]];
}

- (void)postData {
  // 需要上传的参数
  NSDictionary *params = @{@"userName"     : @"rob",
                         @"userEmail"    : @"[email protected]",
                         @"userPassword" : @"password"};
  
  // 需要上传的图片，可以是多张
  NSString *path = [[NSBundle mainBundle] pathForResource:@"avatar" ofType:@"png"];
  
  NSString *boundary = [self generateBoundaryString];

  // configure the request

  NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
  [request setHTTPMethod:@"POST"];

  // set content type

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

  // create body

  NSData *httpBody = [self createBodyWithBoundary:boundary parameters:params paths:@[path] fieldName:fieldName];
  
  // 使用 session 的方案
  NSURLSession *session = [NSURLSession sharedSession];  // use sharedSession or create your own

  NSURLSessionTask *task = [session uploadTaskWithRequest:request fromData:httpBody completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
      if (error) {
          NSLog(@"error = %@", error);
          return;
      }

      NSString *result = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
      NSLog(@"result = %@", result);
  }];
  [task resume];
  
  // 使用 DataTask 的方法
  request.HTTPBody = httpBody;
  NSURLSessionTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
      if (error) {
          NSLog(@"error = %@", error);
          return;
      }

      NSString *result = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
      NSLog(@"result = %@", result);
  }];
  [task resume];
}