Question

In order to start another instance of my program I did something like:

private void button1_Click(object sender, EventArgs e)
{
    Process p = new Process();
    p.StartInfo.FileName = Application.ExecutablePath;
    p.StartInfo.WindowStyle = ProcessWindowStyle.Normal;
    p.Start();
}

And found that stopping the debugger didn’t stop the new window, only the first (-launching) window.

How do I programmatically get the new process to be “under” VS?

Answer 1

Since you’re starting your own program a second time, you know it is a GUI. You can keep the Process reference around and call CloseMainWindow (or Kill) on each of them in your FormClosing event handler:

private List<Process> children = new List<Process>();

private void button1_Click(object sender, EventArgs e)
{
    Process p = new Process();
    p.StartInfo.FileName = Application.ExecutablePath;
    p.StartInfo.WindowStyle = ProcessWindowStyle.Normal;
    p.Start();

    children.Add(p);
}

private Form1_FormClosing(object sender, FormClosingEventArgs e)
{
    foreach (Process p in this.children)
    {
        // posts WM_CLOSE to the main handle of the process
        // which allows a graceful exit, as if the user clicked [X]
        p.CloseMainWindow();
        // p.Kill(); // less graceful, just kill
    }
}