How to call an async method from a console app main method

By Benjamin Perkins · ·

I find myself needing to look this code snippet up time to time so I thought I’d write it up.

Check out some of my other articles I wrote in regards to ASP.NET Core and .Net Core

  • How to call an async method from a console app main method
  • How to deploy a .NET Core console application to Azure, WebJob
  • .NET Core application, where is my EXE, how to publish
  • Create a VNET and access an Azure VM hosted within it from an App Services Web App
  • Create and deploy an ASP.NET Core Web API to Azure Windows

I needed to call an ASP.NET Core Web API which I discussed here, from a .NET Core Console Application, created similar to that shown in Figure 1.

image

Figure 1, how to create a .NET Core Console Application

Using the GetResponseAsync() method of the System.Net.WebResponce class, as you can see it needs to be call asynchronously.

static private async Task callWebApi()
{
   WebResponse response = await WebRequest
       .Create("http://**?**.azurewebsites.net/api/sleepy")
       .GetResponseAsync()
       .ConfigureAwait(false);;
   WriteLine(response.StatusCode.ToString());
}

And in order to call and async method from the Main() method, I did the following.

public static void Main(string[] args)
{
   try
   {
     callWebApi().Wait();
   }
   catch (Exception ex)
   {
     WriteLine($"There was an exception: {ex.ToString()}");
   }
}

You can also call the asynchronous method from the Main() method of the .NET Core console application using the Task.Run() method.

Task.Run(async () => { await callWebApi(); }).GetAwaiter().GetResult();

(it is not recommend to use the GetResult() method as it will block the thread)

Here are some nice articles written about Async Programming:

  • Async Programming – Brownfield Async Development
  • Async/Await – Best Practices in Asynchronous Programming
  • Async Programming : Introduction to Async/Await on ASP.NET