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I'm trying to download file (image ) using my bot, but when I download the image ( which is done successfully ) after using getFile, the image I received is very small 1.7 kb while it's bigger than that on my mobile phone

Ahmad Soliman
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5 Answers5

4

This is an old post. But since there is not a good documentation on how you should download file in telegram bot, for anyone wondering, that's how you should do it(One way of it):

DownloadFile(message.Photo[message.Photo.Length - 1].FileId, @"c:\photo.jpg");

in which: 

    private static async void DownloadFile(string fileId, string path)
    {
        try
        {
            var file = await Bot.GetFileAsync(fileId);

            using (var saveImageStream = new FileStream(path, FileMode.Create))
            {
                await file.FileStream.CopyToAsync(saveImageStream);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error downloading: " + ex.Message);
        }
    }

The message.Photo[message.Photo.Length - 1] is the last element in message.Photo array, which contains the highest quality image data. Obviously you can use DownloadFile to download other kind of files(for example message.Document) as well.

samad montazeri
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3

  1. the getFile Method present a JSON object (the 1.7 KB response) that contain the data for accessing your image file.

  2. also note that telegram create an array of image for any image. the first element of this array contain the small thumbnail of your original image and the latest element of the array contain your original image.

علیرضا
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2
var file = await Bot.GetFileAsync(message.Document.FileId);
FileStream fs=new FileStream("Your Destination Path And File Name",FileMode.Create);
await Bot.DownloadFileAsync(file.FilePath, fs);
fs.Close();
fs.Dispose();
MrPromethee
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Amir Jahani
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1

I use telegram.bot v14.10.0 but I can't find file.FileStream so I find alternative way to get image from telegram. my way is to use telegram api directly for this case.

                    var test =  _myBot.GetFileAsync(e.Message.Photo[e.Message.Photo.Count() - 1].FileId);
                    var download_url = @"https://api.telegram.org/file/bot<token>/" + test.Result.FilePath;
                    using (WebClient client = new WebClient())
                    {
                        client.DownloadFile(new Uri(download_url), @"c:\temp\NewCompanyPicure.png");
                    }
                    //then do what you want with it
anatol
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soroosh elyasi
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0

You need use await botClient.DownloadFileAsync(file.FilePath, saveImageStream); instead await file.FileStream.CopyToAsync(saveImageStream); Your code should look like this:

            static async void DownloadFile(ITelegramBotClient botClient, string fileId, string path)
        {
            try
            {                   
                var file = await botClient.GetFileAsync(fileId);

                using (var saveImageStream = new FileStream(path, FileMode.Create))
                {
                    await botClient.DownloadFileAsync(file.FilePath, saveImageStream);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error downloading: " + ex.Message);
            }
        }

Telegram.Bot from version 14.2.0 commit in examples: https://github.com/TelegramBots/Telegram.Bot.Examples/commit/ff5a44133ad3b0d3c1e4a8b82edce959d0ee0d0e

Artem Semukov
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