c# winforms窗体边框中带边框颜色的圆角边框

using System;
using System.Drawing;
using System.Windows.Forms;

public class RoundedBorderControl : Control
{
    private Color borderColor = Color.Black;
    private int borderRadius = 10;

    public Color BorderColor
    {
        get { return borderColor; }
        set
        {
            borderColor = value;
            Invalidate(); // 强制控件重绘
        }
    }

    public int BorderRadius
    {
        get { return borderRadius; }
        set
        {
            borderRadius = value;
            Invalidate(); // 强制控件重绘
        }
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);
        Graphics g = e.Graphics;
        using (Pen pen = new Pen(borderColor, 2))
        {
            GraphicsPath path = new GraphicsPath();
            path.AddArc(0, 0, borderRadius, borderRadius, 180, 90);
            path.AddLine(borderRadius, 0, Width - borderRadius, 0);
            path.AddArc(Width - borderRadius, 0, borderRadius, borderRadius, 270, 90);
            path.AddLine(Width, borderRadius, Width, Height - borderRadius);
            path.AddArc(Width - borderRadius, Height - borderRadius, borderRadius, borderRadius, 0, 90);
            path.AddLine(Width - borderRadius, Height, borderRadius, Height);
            path.AddArc(0, Height - borderRadius, borderRadius, borderRadius, 90, 90);
            path.CloseFigure();
            g.DrawPath(pen, path);
        }
    }
}