send multiple videos at the same time on telegram bot using c#?

问题

I have create one api for sending multiple videos at the same time in a loop with telegram bot using c#.

I am also getting success for uploading videos on telegram bot.

However, I am facing one issue on this task. Right now I am uploading 1 or 2 videos at the same time in the loop and it's works. But when I try with 10 or more videos, only 2 or 3 videos get uploaded successfully, and suddenly my utility stops.

It would be very helpful if someone could identify my mistake in the following code. I am not getting any errors any but my all the videos don't get uploaded and utility stops.

Here this is my code:

public async Task SendCasesOnTelegramBot()
{             
    DataSet ds = DataAccess.ExecuteDataset(Setting.ConnectionString(), "GetPostForTelegramBot");
    if (ds != null && ds.Tables.Count > 0)
    {
        for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
        {
            string VideoUrl = null;
            VideoUrl = CaseMediaPath + ds.Tables[0].Rows[i]["Url"].ToString();        
            var sb = new StringBuilder();
            sb.Append("abc");             

            await Bot.SendVideoAsync("@abc", video: VideoUrl, caption: sb.ToString(), replyMarkup: ReplyMarkup); 

            await Task.Delay(180000); // i am also try like this but not getting success
        }
    }
}

This is my API, it works very well but only for a few videos.

来源：https://stackoverflow.com/questions/46148978/send-multiple-videos-at-the-same-time-on-telegram-bot-using-c