[c#] Show Console in Windows Application?

Resurrecting a very old thread yet again, since none of the answers here worked very well for me.

I found a simple way that seems pretty robust and simple. It worked for me. The idea:

• Compile your project as a Windows Application. There might be a parent console when your executable starts, but maybe not. The goal is to re-use the existing console if one exists, or create a new one if not.
• AttachConsole(-1) will look for the console of the parent process. If there is one, it attaches to it and you're finished. (I tried this and it worked properly when calling my application from cmd)
• If AttachConsole returned false, there is no parent console. Create one with AllocConsole.

Example:

static class Program
{
    [DllImport( "kernel32.dll", SetLastError = true )]
    static extern bool AllocConsole();

    [DllImport( "kernel32", SetLastError = true )]
    static extern bool AttachConsole( int dwProcessId );

    static void Main(string[] args)
    {
        bool consoleMode = Boolean.Parse(args[0]);
        if (consoleMode)
        {
           if (!AttachConsole(-1))
              AllocConsole();
           Console.WriteLine("consolemode started");
           // ...
        } 
        else
        {
           Application.EnableVisualStyles();
           Application.SetCompatibleTextRenderingDefault(false);
           Application.Run(new Form1());
        }
    }
}

A word of caution : it seems that if you try writing to the console prior to attaching or allocing a console, this approach doesn't work. My guess is the first time you call Console.Write/WriteLine, if there isn't already a console then Windows automatically creates a hidden console somewhere for you. (So perhaps Anthony's ShowConsoleWindow answer is better after you've already written to the console, and my answer is better if you've not yet written to the console). The important thing to note is that this doesn't work:

static void Main(string[] args)
    {
        Console.WriteLine("Welcome to the program");   //< this ruins everything
        bool consoleMode = Boolean.Parse(args[0]);
        if (consoleMode)
        {
           if (!AttachConsole(-1))
              AllocConsole();
           Console.WriteLine("consolemode started");   //< this doesn't get displayed on the parent console
           // ...
        } 
        else
        {
           Application.EnableVisualStyles();
           Application.SetCompatibleTextRenderingDefault(false);
           Application.Run(new Form1());
        }
    }