can not use await in .net core web api?

Question

If I use var result=query.ToList();

it is ok

If I use var result =await query.ToListAsync();

there will be error :

An error occurred using the connection to database on server System.Threading.Tasks.TaskCanceledException

Answer 1

Probably you are inside a Background Task.

Remember that if all Foreground Task end, all background task will be killed.

Answer 2

@Zhi Lv - MSFT I find the problem it was a requestFilter I add in Program.cs

public Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
        {

next();

                return Task.CompletedTask;
}

I remove the filter it is ok but I add the filter is is not ok.

Answer 3

Hi,

You can do that, however your method should be async Task as shown:

public async Task<List<customer>> GetDotNetCount()
{
  var customers = await cuatomerQuery.ToListAsync();
  return customers;
}