由于停靠的面板

Question

我创建了一个无边框的Windows窗体，添加了阴影，拖动的能力以及从任何角度调整它的能力，这就是我所做的，它有点凌乱：

using System.Runtime.InteropServices;

public class MAIN
{
    [DllImport("Gdi32.dll", EntryPoint = "CreateRoundRectRgn")]
    private static extern IntPtr CreateRoundRectRgn
    (
        int nLeftRect, // x-coordinate of upper-left corner
        int nTopRect, // y-coordinate of upper-left corner
        int nRightRect, // x-coordinate of lower-right corner
        int nBottomRect, // y-coordinate of lower-right corner
        int nWidthEllipse, // height of ellipse
        int nHeightEllipse // width of ellipse
    );
    [DllImport("dwmapi.dll")]
    public static extern int DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS pMarInset);
    [DllImport("dwmapi.dll")]
    public static extern int DwmSetWindowAttribute(IntPtr hwnd, int attr, ref int attrValue, int attrSize);
    [DllImport("dwmapi.dll")]
    public static extern int DwmIsCompositionEnabled(ref int pfEnabled);
    private bool m_aeroEnabled;                     // variables for box shadow
    private const int CS_DROPSHADOW = 0x00020000;
    private const int WM_NCPAINT = 0x0085;
    private const int WM_ACTIVATEAPP = 0x001C;
    public struct MARGINS                           // struct for box shadow
    {
        public int leftWidth;
        public int rightWidth;
        public int topHeight;
        public int bottomHeight;
    }
    private const int WM_NCHITTEST = 0x84;          // variables for dragging the form
    private const int HTCLIENT = 0x1;
    private const int HTCAPTION = 0x2;
    protected override CreateParams CreateParams
    {
        get
        {
            m_aeroEnabled = CheckAeroEnabled();

            CreateParams cp = base.CreateParams;
            if (!m_aeroEnabled)
                cp.ClassStyle |= CS_DROPSHADOW;

            return cp;
        }
    }
    private bool CheckAeroEnabled()
    {
        if (Environment.OSVersion.Version.Major >= 6)
        {
            int enabled = 0;
            DwmIsCompositionEnabled(ref enabled);
            return (enabled == 1) ? true : false;
        }
        return false;
    }
    protected override void WndProc(ref Message m)
    {
        const int wmNcHitTest = 0x84;
        const int htLeft = 10;
        const int htRight = 11;
        const int htTop = 12;
        const int htTopLeft = 13;
        const int htTopRight = 14;
        const int htBottom = 15;
        const int htBottomLeft = 16;
        const int htBottomRight = 17;
        bool handled = false;
        switch (m.Msg)
        {
            case WM_NCPAINT:                        // box shadow
                if (m_aeroEnabled)
                {
                    var v = 2;
                    DwmSetWindowAttribute(this.Handle, 2, ref v, 4);
                    MARGINS margins = new MARGINS()
                    {
                        bottomHeight = 1,
                        leftWidth = 1,
                        rightWidth = 1,
                        topHeight = 1
                    };
                    DwmExtendFrameIntoClientArea(this.Handle, ref margins);

                }
                break;
            default:
                break;
        }
        if (m.Msg == wmNcHitTest)
        {
            int x = (int)(m.LParam.ToInt64() & 0xFFFF);
            int y = (int)((m.LParam.ToInt64() & 0xFFFF0000) >> 16);
            Point pt = PointToClient(new Point(x, y));
            Size clientSize = ClientSize;
            ///allow resize on the lower right corner
            if (pt.X >= clientSize.Width - 16 && pt.Y >= clientSize.Height - 16 && clientSize.Height >= 16)
            {
                m.Result = (IntPtr)(IsMirrored ? htBottomLeft : htBottomRight);
                return;
            }
            ///allow resize on the lower left corner
            if (pt.X <= 16 && pt.Y >= clientSize.Height - 16 && clientSize.Height >= 16)
            {
                m.Result = (IntPtr)(IsMirrored ? htBottomRight : htBottomLeft);
                return;
            }
            ///allow resize on the upper right corner
            if (pt.X <= 16 && pt.Y <= 16 && clientSize.Height >= 16)
            {
                m.Result = (IntPtr)(IsMirrored ? htTopRight : htTopLeft);
                return;
            }
            ///allow resize on the upper left corner
            if (pt.X >= clientSize.Width - 16 && pt.Y <= 16 && clientSize.Height >= 16)
            {
                m.Result = (IntPtr)(IsMirrored ? htTopLeft : htTopRight);
                return;
            }
            ///allow resize on the top border
            if (pt.Y <= 16 && clientSize.Height >= 16)
            {
                m.Result = (IntPtr)(htTop);
                return;
            }
            ///allow resize on the bottom border
            if (pt.Y >= clientSize.Height - 16 && clientSize.Height >= 16)
            {
                m.Result = (IntPtr)(htBottom);
                return;
            }
            ///allow resize on the left border
            if (pt.X <= 16 && clientSize.Height >= 16)
            {
                m.Result = (IntPtr)(htLeft);
                return;
            }
            ///allow resize on the right border
            if (pt.X >= clientSize.Width - 16 && clientSize.Height >= 16)
            {
                m.Result = (IntPtr)(htRight);
                return;
            }
        }
        if (!handled)
            base.WndProc(ref m);
    }
    public MAIN()
    {
        InitializeComponent();
        m_aeroEnabled = false;
    }
    private Point mMousePos;
    private Point mFormPos;
    private bool mDragging;
    private void Header_MouseDown(object sender, MouseEventArgs e)
    {
        mDragging = true;
        mMousePos = Header.PointToScreen(e.Location);
        mFormPos = Location; 
    } 
    private void Header_MouseUp(object sender, MouseEventArgs e)
    {
        mDragging = false;     
    }
    private void Header_MouseMove(object sender, MouseEventArgs e)
    {
        if (!mDragging) return;
        Point pos = Header.PointToScreen(e.Location);
        Left = mFormPos.X + pos.X - mMousePos.X;
        Top = mFormPos.Y + pos.Y - mMousePos.Y;
    }
}

MAIN是表单的名称，而Header是我的面板的名称，我遇到的问题是尝试从顶部调整大小，因为面板已停靠，我也是我希望将这段代码放在一个类中，并在创建新表单时调用它。任何帮助都非常受欢迎。