.NET (Core and Framework)

<br />
This all works except when the process has actually started the winforms app puts itself in front of the process which has just started<br />

[DllImport("user32")]
private static extern IntPtr SetForegroundWindow( IntPtr hWnd );
[DllImport("user32")]
private static extern int GetAsyncKeyState( long vKey );

// prProc is the initiated process...
private void MainForm_Activated(object sender, System.EventArgs e)
{
	try
	{
		// A mouse button pressed? If so presume the window was
                // activated by the user.
		if (( GetAsyncKeyState( 0x01 /* VK_LBUTTON */ ) & ( 1 << 15 )) == ( 1 << 15 ) ||
		    ( GetAsyncKeyState( 0x02 /* VK_RBUTTON */ ) & ( 1 << 15 )) == ( 1 << 15 ) ||
		    ( GetAsyncKeyState( 0x04 /* VK_MBUTTON */ ) & ( 1 << 15 )) == ( 1 << 15 ))
		{
			// Will not be needed anymore...
			prProc = null;
		}
		else if ( prProc != null )
		{
			// Process still running?
			if ( prProc.HasExited == false ) 
				// Put it's window upfront.
				SetForegroundWindow( prProc.MainWindowHandle );
		        // No longer necessary.
			prProc = null;
		}
	}
	catch ( InvalidOperationException )
	{
                // We did a SetForgroundWindow() when the process died
                // if we get here...
	}
}