.net - Detect when drive is mounted or changes state (WM_DEVICECHANGE for WPF)?

Question

I am writing a directory selector control for WPF, and I would like to add/remove a drive from the directory tree when it gets mounted or unmounted or when it becomes ready or not ready (e.g. the user inserts or removes a CD). I am looking for a system event similar to WM_DEVICECHANGE.

konstantin

Answer 1

Even though you are using WPF, you can still intercept WM_DEVICECHANGE. You could either attach to an existing window procedure using WPF callback methods, or you could use a System.Windows.Forms.NativeWindow (my preferred method, more control and easier, but you do need to add a reference to System.Windows.Forms.dll)

// in your window's code behind
private static int WM_DEVICECHANGE = 0x0219;

protected override void OnSourceInitialized(EventArgs e)
{
    WindowInteropHelper helper = new WindowInteropHelper(this);
    SystemEventIntercept intercept = new SystemEventIntercept(helper.Handle);
    base.OnSourceInitialized(e);
}

class SystemEventIntercept : System.Windows.Forms.NativeWindow
{
    public SystemEventIntercept(IntPtr handle)
    {
        this.AssignHandle(handle);
    }

    protected override void WndProc(ref Winforms.Message m)
    {
        if (m.Msg == WM_DEVICECHANGE)
        {
            // do something
        }

        base.WndProc(ref m);
    }
}