uploadStickerFile method
Use this method to upload a .png file with a sticker for later use in createNewStickerSet and addStickerToSet methods (can be used multiple times)
Returns the uploaded File
on success.
Implementation
Future<File> uploadStickerFile(int user_id, io.File png_sticker) async {
var requestUrl = _apiUri('uploadStickerFile');
var body = <String, dynamic>{'user_id': user_id};
// filename cannot be empty to post to Telegram server
var files = List<MultipartFile>.filled(
1,
MultipartFile(
'png_sticker', png_sticker.openRead(), png_sticker.lengthSync(),
filename: '${png_sticker.lengthSync()}'));
return File.fromJson(
await HttpClient.httpMultipartPost(requestUrl, files, body: body));
}