ChromeDriver console application hide

Yes, you need modify source code in WebDriver\DriverService.cs in Start(); add:

this.driverServiceProcess.StartInfo.CreateNoWindow = true;

This is possible now, using the headless option. Might not have been available then. Running Chrome Headless

Translated into C#, you can do this:

ChromeOptions options = new ChromeOptions();
options.AddArgument("headless");
ChromeDriver driver = new ChromeDriver(options);

Now the browser window is invisible, while the rest of the program stays the same.

Modifying source code in WebDriver\DriverService.cs is not necessary for this in latest WebDriver. You just need to instantiate ChromeDriverService and set HideCommandPromptWindow to true and then instantiate ChromeDriver by that service and ChromeOptions. I am giving C# code example below

var chromeDriverService = ChromeDriverService.CreateDefaultService();
chromeDriverService.HideCommandPromptWindow = true;
return new ChromeDriver(chromeDriverService,  new ChromeOptions());

No, there is no way to hide the console window of the chromedriver.exe in the .NET bindings without modifying the bindings source code. This is seen as a feature of the bindings, as it makes it very easy to see when your code hasn't correctly cleaned up the resources of the ChromeDriver, since the console window remains open. In the case of some other languages, if your code does not properly clean up the instance of ChromeDriver by calling the quit() method on the WebDriver object, you can end up with a zombie chromedriver.exe process running on your machine.