Starting a GUI app in hidden mode?

[haddaway]

I am using the following code:

Dim si As New ProcessStartInfo
si.CreateNoWindow = True
si.UseShellExecute = False
si.WindowStyle = ProcessWindowStyle.Hidden
si.FileName = "notepad.exe"

Process.Start(si)

This is just an example, but I would like to start my application in hidden mode AND redirect output. But this does not work! Any ideas why the above code does not work?

 

[mansii]

Setting:

si.UseShellExecute = True

hides the application.

If that's what you are trying to achieve.

Regards,
mansii

 

[haddaway]

Yes, but that prevents me from redirecting output.

 

[mansii]

Play arround with this:

1. Create an old styled Batch file in C:\ folder -> Test.Bat

dir c:\ > %1

2. Pass the argument

Dim si As New ProcessStartInfo
si.WindowStyle = ProcessWindowStyle.Normal
si.CreateNoWindow = True
si.UseShellExecute = False
si.FileName = "C:\Test.Bat"
si.RedirectStandardOutput = True
si.Arguments = "c:\TestResult.txt"
Dim p As New Process
p.StartInfo = si
p.Start()
p.StandardOutput.ReadToEnd()
p.WaitForExit()

make sure that your application close itself when it finishes processing, so it (the process) doesn't stay in memory.

Regards,
mansii

 

[haddaway]

That works for a commandwindow. I would like to have the ability to do this with for example Notepad.exe. Unfortunately, that program and other "real" GUI programs won't hide like they do when using the WindowsAPI function "CreateProcessWithLogonW".

 

[mansii]

Apologize, haddaway. But I did not get what you are trying to achieve. I.e. Start the Notepad.exe (for example) then hide it from any user.

Perhaps, a Windows Service application is more suitable.

 

[haddaway]

Thanks mansii, Notepad was just an example. It could be any GUI application. I don't know why they have failed with this or if there exists a workaround.

If someone wants to try this further here is what I want to achieve in my example:

1. start Notepad.exe in hidden mode via Process.Start, no bat file, just pointing to the exe
2. enable redirect output (even though Notepad does not give any output - again, this is just an example)

 

[earthandfire]

As far as I am aware only console apps use the redirectable stdin and stdout handles, WinForms apps don't. So I don't think that you will be able to achieve both objectives with regard to starting any one particular application.

In other words, if the app you want to start is a console app you can redirect stdin and stdout (and hide the window) - for a WinForms app you can only hide the window, although you may be able to locate the handles of the form's UI elements and pick up the contents of those.


Hope this helps.

 

[haddaway]

Yes, maybe they don't. But I would like to have the possibility to hide it. My problem is that I always capture output, but it is the user that selects an application to start and sometimes they want to hide the GUI applications. I don't know any way to determine if it is a GUI application or not programatically. If I could, I would stop the automatic output. When using the Windows API function CreateProcessWithLogonW I am able to redirect and hide, I wish that was possible in process.start as well.

Anyway, do you know a way to determine if it's a gui app or not, programatically?