C#. How to make a form move by removing its border?

Question

C++ / C#

Good afternoon. Tell me how to make the form move by removing its frame?
That is, I have MainForm turned off ControlBox and BorderStyle - None
And the form does not move now .. How to return the ability to move it? thanks in advance

Answer 1

protected override void WndProc(ref Message m)
{
            switch (m.Msg)
            {
                case WndHelper.WM_NCHITTEST:
                    {
                        m.Result = (IntPtr)WndHelper.HTCAPTION; 
                        return;
                    }
                default:
                    break;
            }
            base.WndProc(ref m);
}

public const int WM_NCHITTEST = 0x84;
public const int HTCAPTION = 0x2;