I have 2 programs (.exe) which I've created in .NET. We'll call them the Master and the Worker. The Master starts 1 or more Workers. The Worker will not be interacted with by the user, but it is a WinForms app that receives commands and runs WinForms components based on the commands it receives from the Master.
I want the Worker app to run completely hidden (except showing up in the Task Manager of course). I thought that I could accomplish this with the StartInfo.CreateNoWindow and StartInfo.WindowStyle properties, but I still see the Client.exe window and components in the form. However, it doesn't show up in the taskbar.
Process process = new Process
{
EnableRaisingEvents = true,
StartInfo =
{
CreateNoWindow = true,
WindowStyle = ProcessWindowStyle.Hidden,
FileName = "Client.exe",
UseShellExecute = false,
ErrorDialog = false,
}
};
What do I need to do to let Client.exe run, but not show up?ㅤㅤㅤㅤㅤ
Your usage of CreateNoWindow
/WindowStyle
works fine on my system with notepad.exe (e.g. it is hidden but running in the background), so it's probably something the WinForms app is doing. Some ideas:
Option 1: If you control the WinForms worker process, you can override Control.SetVisibleCore
to always hide the form. If you don't want to always hide it, you can pass a command-line argument to it, e.g. /hide
that will cause it to be hidden. Example (assuming there's already code-behind for the form):
public partial class MyForm : Form
{
public MyForm()
{
InitializeComponent();
}
protected override void SetVisibleCore(bool value)
{
// You'd probably want to parse the command line.
if (Environment.CommandLine.Contains("/hide"))
base.SetVisibleCore(false);
else
base.SetVisibleCore(value);
}
}
With this, running MyForm.exe
results in a process with a visible form. Running MyForm.exe /hide
results in a process with a hidden form. You could pass the /hide
argument from your master process, so then normal users running the application will still see it.
Option 2: You can hide the application after it starts by doing a P/Invoke to ShowWindow
. More info on this here. This has the drawback that you can sometimes see the worker window flicker into existence before being hidden. Example:
class Program
{
public static void Main(string[] args)
{
ProcessStartInfo psi = new ProcessStartInfo()
{
FileName = @"C:\windows\system32\notepad.exe",
};
Process process = Process.Start(psi);
// Wait until the process has a main window handle.
while (process.MainWindowHandle == IntPtr.Zero)
{
process.Refresh();
}
ShowWindow(process.MainWindowHandle, SW_HIDE);
}
const int SW_HIDE = 0;
[DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
}