在C#中绘制带圆角,边框和渐变填充的图像

using System;
using System.Drawing;
using System.Drawing.Drawing2D;

public class Program
{
    public static void Main()
    {
        int width = 200;
        int height = 200;
        int cornerRadius = 20;
        int borderWidth = 5;
        Color borderColor = Color.Black;
        Color startColor = Color.Red;
        Color endColor = Color.Yellow;

        Bitmap bitmap = new Bitmap(width, height);
        Graphics graphics = Graphics.FromImage(bitmap);

        // 绘制带圆角的矩形
        Rectangle rectangle = new Rectangle(borderWidth / 2, borderWidth / 2, width - borderWidth, height - borderWidth);
        GraphicsPath path = GetRoundedRectangle(rectangle, cornerRadius);
        Pen borderPen = new Pen(borderColor, borderWidth);
        graphics.DrawPath(borderPen, path);

        // 渐变填充
        LinearGradientBrush brush = new LinearGradientBrush(rectangle, startColor, endColor, LinearGradientMode.Vertical);
        graphics.FillPath(brush, path);

        // 绘制圆角
        Rectangle ellipseRect = new Rectangle(width / 2 - cornerRadius / 2, height / 2 - cornerRadius / 2, cornerRadius, cornerRadius);
        graphics.FillEllipse(Brushes.White, ellipseRect);

        // 保存图像
        bitmap.Save("image.png");
    }

    // 创建带圆角的路径
    public static GraphicsPath GetRoundedRectangle(Rectangle rectangle, int cornerRadius)
    {
        GraphicsPath path = new GraphicsPath();
        int diameter = cornerRadius * 2;
        Rectangle arcRect = new Rectangle(rectangle.X, rectangle.Y, diameter, diameter);

        // 左上角
        path.AddArc(arcRect, 180, 90);
        // 右上角
        arcRect.X = rectangle.Right - diameter;
        path.AddArc(arcRect, 270, 90);
        // 右下角
        arcRect.Y = rectangle.Bottom - diameter;
        path.AddArc(arcRect, 0, 90);
        // 左下角
        arcRect.X = rectangle.Left;
        path.AddArc(arcRect, 90, 90);

        path.CloseFigure();
        return path;
    }
}