c# - 动态调整用户控件的大小

Question

我正在尝试调整我动态创建的面板的大小。调整大小时，面板的边框会捕捉网格。但它的宽度/高度并没有像理想情况下那样改变。只要鼠标指针在锚点上，宽度/高度就会不断变化。这是我的代码。我应该如何解决这个问题？

Tile.cs（这是一个用户控件。）

namespace WindowsFormsApp6
{
    public partial class Tile : UserControl
    {
        bool mouseClicked = false;
        int pixels = 16;

        public Tile()
        {
            InitializeComponent();
            ShowHideAnchorPoints(true);
        }

        private void ShowHideAnchorPoints(bool flag)
        {
            rightAnchor.Visible =
            leftAnchor.Visible =
            topAnchor.Visible =
            bottomAnchor.Visible = flag;
        }

        private void Anchor_MouseDown(object sender, MouseEventArgs e)
        {
            mouseClicked = true;
            ShowHideAnchorPoints(false);
        }

        private void Anchor_MouseUp(object sender, MouseEventArgs e)
        {
            mouseClicked = false;
            ShowHideAnchorPoints(true);
        }


        private void topAnchor_MouseMove(object sender, MouseEventArgs e)
        {

            if (mouseClicked)
            {
                Location = GridSnapY(Location, e.Y);
                Height -= e.Y;
            }
        }

        private void rightAnchor_MouseMove(object sender, MouseEventArgs e)
        {
            if (mouseClicked)
            {
                int width = (sender as Panel).Right + e.X;
                Width = SnapWidth(width);
            }
        }

        private void bottomAnchor_MouseMove(object sender, MouseEventArgs e)
        {
            if (mouseClicked)
            {
                int height = (sender as Panel).Bottom + e.Y;
                Height = height;
                Height = SnapHeight(height);
            }
        }

        private void leftAnchor_MouseMove(object sender, MouseEventArgs e)
        {
            if (mouseClicked)
            {
                Location = GridSnapX(Location, e.X);
                Width -= e.X;
            }
        }



        private Point GridSnapX(Point location, int x)
        {
            Point p = new Point(location.X + x, location.Y);
            if (p.X % pixels > pixels/2)
            {
                p.X += pixels - (p.X % pixels);
            }
            else
            {
                p.X -= (p.X % pixels);
            }

            return p;
        }

        private Point GridSnapY(Point location, int y)
        {
            Point p = new Point(location.X, location.Y + y);
            if (p.Y % pixels > pixels/2)
            {
                p.Y += pixels - (p.Y % pixels);
            }
            else
            {
                p.Y -= (p.Y % pixels);
            }

            return p;
        }

        private int SnapHeight(int height)
        {
            if (height % pixels > pixels/2)
            {
                height += pixels - (height % pixels);
            }
            else
            {
                height -= (height % pixels);
            }

            return height;
        }

        private int SnapWidth(int width)
        {
            if (width % pixels > pixels/2)
            {
                width += pixels - (width % pixels);
            }
            else
            {
                width -= (width % pixels);
            }

            return width;
        }

Form1.cs（这里的画布是使用网格点创建的，用户可以在其中绘制平铺并调整其大小）

namespace WindowsFormsApp6
{
    public partial class Form1 : Form
    {
        Tile t;
        Point locationXY;
        Point locationX1Y1;
        bool isMouseDown;

        public Form1()
        {
            InitializeComponent();
            canvas.BackgroundImage = CreatePixelGrid();
        }

        private Image CreatePixelGrid()
        {
            int width = canvas.Width;
            int height = canvas.Height;
            int pixels = 16;
            Bitmap image = new Bitmap(width, height);
            for (int y = 0; y < height; y += pixels)
            {
                for (int x = 0; x < width; x += pixels)
                {
                    image.SetPixel(x, y, Color.Black);
                }
            }
            return image;

        }

        private void DrawTile()
        {
            t = new Tile();
            locationXY.X = Math.Min(locationXY.X, locationX1Y1.X);
            locationXY.Y = Math.Min(locationXY.Y, locationX1Y1.Y);
            t.Location = locationXY;
            t.Height = Math.Abs(locationX1Y1.Y - locationXY.Y);
            t.Width = Math.Abs(locationX1Y1.X - locationXY.X);
            t.BorderStyle = BorderStyle.None;
            canvas.Controls.Add(t);
            t.BringToFront();
        }

        private void canvas_MouseDown(object sender, MouseEventArgs e)
        {

            isMouseDown = true;
            locationXY = e.Location;

        }

        private void canvas_MouseMove(object sender, MouseEventArgs e)
        {
            if (isMouseDown)
            {
                locationX1Y1 = e.Location;
                Refresh();
            }
        }

        private void canvas_MouseUp(object sender, MouseEventArgs e)
        {
            isMouseDown = false;
            DrawTile();
        }



    }
}

这是绘制瓷砖后表单的外观。目前我只在顶部、底部、右侧和左侧锚点上工作。