關於 GDI+ 繪圖的輔助類

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace Lhyi.Helper
{
    /// <summary>
    /// 關於 GDI+ 繪圖的輔助類
    /// </summary>
    public class DrawHelper
    {
        #region RendererBackground 渲染背景圖片，使背景圖片不失真
        
        /// <summary>
        /// 渲染背景圖片,使背景圖片不失真
        /// </summary>
        /// <param name="g"></param>
        /// <param name="rect"></param>
        /// <param name="backgroundImage"></param>
        /// <param name="method"></param>
        public static void RendererBackground(Graphics g, Rectangle rect, Image backgroundImage, bool method)
        {
            if (!method)
            {
                g.DrawImage(backgroundImage, new Rectangle(rect.X + 0, rect.Y, 5, rect.Height), 0, 0, 5, backgroundImage.Height, GraphicsUnit.Pixel);
                g.DrawImage(backgroundImage, new Rectangle(rect.X + 5, rect.Y, rect.Width - 10, rect.Height), 5, 0, backgroundImage.Width - 10, backgroundImage.Height, GraphicsUnit.Pixel);
                g.DrawImage(backgroundImage, new Rectangle(rect.X + rect.Width - 5, rect.Y, 5, rect.Height), backgroundImage.Width - 5, 0, 5, backgroundImage.Height, GraphicsUnit.Pixel);
            }
            else
            {
                DrawHelper.RendererBackground(g, rect, 5, backgroundImage);
            }
        }

        /// <summary>
        /// 渲染背景圖片,使背景圖片不失真
        /// </summary>
        /// <param name="g"></param>
        /// <param name="rect"></param>
        /// <param name="cut"></param>
        /// <param name="backgroundImage"></param>
        public static void RendererBackground(Graphics g, Rectangle rect, int cut, Image backgroundImage)
        {
            //左上角
            g.DrawImage(backgroundImage, new Rectangle(rect.X, rect.Y, cut, cut), 0, 0, cut, cut, GraphicsUnit.Pixel);
            //上邊
            g.DrawImage(backgroundImage, new Rectangle(rect.X + cut, rect.Y, rect.Width - cut * 2, cut), cut, 0, backgroundImage.Width - cut * 2, cut, GraphicsUnit.Pixel);
            //右上角
            g.DrawImage(backgroundImage, new Rectangle(rect.X + rect.Width - cut, rect.Y, cut, cut), backgroundImage.Width - cut, 0, cut, cut, GraphicsUnit.Pixel);
            //左邊
            g.DrawImage(backgroundImage, new Rectangle(rect.X, rect.Y + cut, cut, rect.Height - cut * 2), 0, cut, cut, backgroundImage.Height - cut*2, GraphicsUnit.Pixel);
            //左下角
            g.DrawImage(backgroundImage, new Rectangle(rect.X, rect.Y + rect.Height - cut, cut, cut), 0, backgroundImage.Height - cut, cut, cut, GraphicsUnit.Pixel);
            //右邊
            g.DrawImage(backgroundImage, new Rectangle(rect.X + rect.Width - cut, rect.Y + cut, cut, rect.Height - cut * 2), backgroundImage.Width - cut, cut, cut, backgroundImage.Height - cut*2, GraphicsUnit.Pixel);
            //右下角
            g.DrawImage(backgroundImage, new Rectangle(rect.X + rect.Width - cut, rect.Y + rect.Height - cut, cut, cut), backgroundImage.Width - cut, backgroundImage.Height - cut, cut, cut, GraphicsUnit.Pixel);
            //下邊
            g.DrawImage(backgroundImage, new Rectangle(rect.X + cut, rect.Y + rect.Height - cut, rect.Width - cut * 2, cut), cut, backgroundImage.Height - cut, backgroundImage.Width - cut * 2, cut, GraphicsUnit.Pixel);
            //平鋪中間
            g.DrawImage(backgroundImage, new Rectangle(rect.X + cut, rect.Y + cut, rect.Width - cut * 2, rect.Height - cut * 2), cut, cut, backgroundImage.Width - cut * 2, backgroundImage.Height - cut * 2, GraphicsUnit.Pixel);
        }

        #endregion

        /// <summary>
        /// 
        /// </summary>
        /// <param name="g"></param>
        /// <param name="image"></param>
        /// <param name="x1"></param>
        /// <param name="y1"></param>
        /// <param name="width1"></param>
        /// <param name="height1"></param>
        /// <param name="x2"></param>
        /// <param name="y2"></param>
        /// <param name="width2"></param>
        /// <param name="height2"></param>
        public static void DrawImage(Graphics g, Image image, int x1, int y1, int width1, int height1, int x2, int y2, int width2, int height2)
        {
            g.DrawImage(image, new Rectangle(x1, y1, width1, height1), x2, y2, width2, height2, GraphicsUnit.Pixel);
        }

        #region CreateRoundPath 構建圓角路徑

        /// <summary>
        /// 構建圓角路徑
        /// </summary>
        /// <param name="rect"></param>
        /// <param name="cornerRadius"></param>
        /// <returns></returns>
        public static GraphicsPath CreateRoundPath(Rectangle rect, int cornerRadius)
        {
            GraphicsPath roundedRect = new GraphicsPath();
            roundedRect.AddArc(rect.X, rect.Y, cornerRadius * 2, cornerRadius * 2, 180, 90);
            roundedRect.AddLine(rect.X + cornerRadius, rect.Y, rect.Right - cornerRadius * 2, rect.Y);
            roundedRect.AddArc(rect.X + rect.Width - cornerRadius * 2, rect.Y, cornerRadius * 2, cornerRadius * 2, 270, 90);
            roundedRect.AddLine(rect.Right, rect.Y + cornerRadius * 2, rect.Right, rect.Y + rect.Height - cornerRadius * 2);
            roundedRect.AddArc(rect.X + rect.Width - cornerRadius * 2, rect.Y + rect.Height - cornerRadius * 2, cornerRadius * 2, cornerRadius * 2, 0, 90);
            roundedRect.AddLine(rect.Right - cornerRadius * 2, rect.Bottom, rect.X + cornerRadius * 2, rect.Bottom);
            roundedRect.AddArc(rect.X, rect.Bottom - cornerRadius * 2, cornerRadius * 2, cornerRadius * 2, 90, 90);
            roundedRect.AddLine(rect.X, rect.Bottom - cornerRadius * 2, rect.X, rect.Y + cornerRadius * 2);
            roundedRect.CloseFigure();
            return roundedRect;
        }

        /// <summary>
        /// 構建圓角路徑
        /// </summary>
        /// <param name="r"></param>
        /// <param name="r1"></param>
        /// <param name="r2"></param>
        /// <param name="r3"></param>
        /// <param name="r4"></param>
        /// <returns></returns>
        public static GraphicsPath CreateRoundRect(RectangleF r, float r1, float r2, float r3, float r4)
        {
            float x = r.X;
            float y = r.Y;
            float width = r.Width;
            float height = r.Height;
            GraphicsPath path = new GraphicsPath();
            path.AddBezier(x, y + r1, x, y, x + r1, y, x + r1, y);
            path.AddLine(x + r1, y, (x + width) - r2, y);
            path.AddBezier((x + width) - r2, y, x + width, y, x + width, y + r2, x + width, y + r2);
            path.AddLine((float)(x + width), (float)(y + r2), (float)(x + width), (float)((y + height) - r3));
            path.AddBezier((float)(x + width), (float)((y + height) - r3), (float)(x + width), (float)(y + height), (float)((x + width) - r3), (float)(y + height), (float)((x + width) - r3), (float)(y + height));
            path.AddLine((float)((x + width) - r3), (float)(y + height), (float)(x + r4), (float)(y + height));
            path.AddBezier(x + r4, y + height, x, y + height, x, (y + height) - r4, x, (y + height) - r4);
            path.AddLine(x, (y + height) - r4, x, y + r1);
            return path;
        }

        #endregion
    }
}