How can I tell if a process has a graphical interface?

Question

I'm using automation to test an application, but sometimes I want to start the application via a batch file. When I run "process.WaitForInputIdle(100)" I get an error:

"WaitForInputIdle failed. This could be because the process does not have a graphical interface."

How can I tell if the process has a graphical interface or not?

Answer 1

See Environment.UserInteractive. That will identify whether the process has an interface at all, e.g. services are not user interactive.

You could also look at Process.MainWindowHandle which will tell you whether there is a graphical interface.

A combination of these two checks should cover all the possibilities.

Answer 2

You can simply try and catch the exception:

Process process = ...
try
{
    process.WaitForInputIdle(100);
}
catch (InvalidOperationException ex)
{
    // no graphical interface
}

Answer 3

I was think along the lines of this, Still ugly but trys to avoid exceptions.

Process process = ...

bool hasUI = false;

if (!process.HasExited)
{
    try
    {
        hasUI = process.MainWindowHandle != IntPtr.Zero;
    }
    catch (InvalidOperationException)
    {
        if (!process.HasExited)
            throw;
    }
}

if (!process.HasExited && hasUI)
{

    try
    {
        process.WaitForInputIdle(100);
    }
    catch (InvalidOperationException)
    {
        if (!process.HasExited)
            throw;
    }
}