winform图片裁剪

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Text;
using System.Windows.Forms;

namespace bitmaprerote
{
    public partial class caijian : Form
    {
        public caijian()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 剪裁
        /// </summary>
        /// <param name="b">原始Bitmap</param>
        /// <param name="StartX">开始坐标X</param>
        /// <param name="StartY">开始坐标Y</param>
        /// <param name="iWidth">宽度</param>
        /// <param name="iHeight">高度</param>
        /// <returns>剪裁后的Bitmap</returns>
        public static Bitmap KiCut(Bitmap b, int StartX, int StartY, int iWidth, int iHeight)
        {
            if (b == null)
            {
                return null;
            }

            int w = b.Width;
            int h = b.Height;
            if (StartX >= w || StartY >= h)
            {
                return null;
            }

            if (StartX + iWidth > w)
            {
                iWidth = w - StartX;
            }

            if (StartY + iHeight > h)
            {
                iHeight = h - StartY;
            }
            try
            {
                Bitmap bmpOut = new Bitmap(iWidth, iHeight, PixelFormat.Format24bppRgb);
                Graphics g = Graphics.FromImage(bmpOut);
                g.DrawImage(b, new Rectangle(0, 0, iWidth, iHeight), new Rectangle(StartX, StartY, iWidth, iHeight), GraphicsUnit.Pixel);
                g.Dispose();
                return bmpOut;
            }
            catch
            {
                return null;
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Bitmap map = new Bitmap("F:\\hj.jpg");
            map = KiCut(map, pictureBox1.Location.X, pictureBox1.Location.Y, 60, 60);
            pictureBox1.Image = map;
        }
    }
}