照着赵春江那本书写的代码~ 代码和下面从网上copy来的一致~但是我的显示为什么是这样的哇？恳请各位高手解决~


双击“histogram”控件，并在其中添加如下代码：
       private void histogram_Click(object sender, EventArgs e)
        {
            if (curBitmap != null)
            {
                //定义并实例化新窗体，并把图像数据传递给它；
                histForm histoGram = new histForm(curBitmap);
                //打开从窗体；
                histoGram.ShowDialog();
            }
            else
            {
                //没有打开图像时，弹出对应的提示框；
                MessageBox.Show("请先打开图像！");
            }
        }
 
然后在打开的histForm窗体中先定义以下3个数据成员：
        //图像数据
        private System.Drawing.Bitmap bmpHist;
        //为了标识横纵坐标的标识；
        private int[] countPixel;
        
        private int maxPixel=1000;//记录最大的灰度级个数
为了实现两个窗体之间的数据传递，需要改写histForm窗体的构造函数，其代码如下：
       public histForm(Bitmap bmp)
        {
            InitializeComponent();
            //把主窗体的图像数据传递给从窗体
            bmpHist = bmp;
            //灰度级计数
            countPixel=new int[256];
        }
 
分别为histForm窗体添加Paint和Load事件，Paint事件用于绘制直方图，Load事件用于计算各个灰度级所具有的像素个数，其代码如下：
                                                              
1——————————————————————Paint事件；
        private void histForm_Paint(object sender, PaintEventArgs e)
        {
            //获取Graphics对象
            Graphics g = e.Graphics;

            //创建一个宽度为1的黑色钢笔
            Pen curPen = new Pen(Brushes.Black, 1);
            //绘制坐标轴
            //（y，x）=(50,240)原点；
            g.DrawLine(curPen,50,240,320,240);//横坐标
            g.DrawLine(curPen,50,240,50,30);//纵坐标
            //绘制并标识坐标刻度
            g.DrawLine(curPen, 100, 240, 100, 242);
            g.DrawLine(curPen, 150, 240, 150, 242);
            g.DrawLine(curPen, 200, 240, 200, 242);
            g.DrawLine(curPen, 250, 240, 250, 242);
            g.DrawLine(curPen, 300, 240, 300, 242);
            g.DrawString("0", new Font("New Timer", 8), Brushes.Black, new PointF(46, 242));
            g.DrawString("50", new Font("New Timer", 8), Brushes.Black, new PointF(92, 242));
            g.DrawString("100", new Font("New Timer", 8), Brushes.Black, new PointF(139, 242));
            g.DrawString("150", new Font("New Timer", 8), Brushes.Black, new PointF(189, 242));
            g.DrawString("200", new Font("New Timer", 8), Brushes.Black, new PointF(239, 242));
            g.DrawString("250", new Font("New Timer", 8), Brushes.Black, new PointF(289, 242));
            g.DrawLine(curPen,48,40,50,40);
            g.DrawString(maxPixel.ToString(), new Font("New Timer", 8), Brushes.Black, new PointF(18, 38));
            //开始绘制直方图
            double temp = 0;
            for (int i = 0; i < 256;i++ )
            {
                //计算出纵坐标的长度
                temp = 200.0 * countPixel[i] / maxPixel;
                g.DrawLine(curPen,50+i,240,50+i,240-(int)temp);
            }
            //释放对象
            curPen.Dispose();
        }
2————————————————Load事件：

        /// <summary>
        /// 直方图的绘制；
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void histForm_Load(object sender, EventArgs e)
        {
            //锁定8位灰度位图
            Rectangle rect = new Rectangle(0, 0, bmpHist.Width, bmpHist.Height);
            System.Drawing.Imaging.BitmapData bmpData = bmpHist.LockBits(rect,
                System.Drawing.Imaging.ImageLockMode.ReadOnly,
                bmpHist.PixelFormat);
            IntPtr ptr = bmpData.Scan0;
            int bytes = bmpHist.Width * bmpHist.Height*3;
            byte[] graybValues = new byte[bytes];
            System.Runtime.InteropServices.Marshal.Copy(ptr, graybValues, 0, bytes);
            byte temp = 0;
            maxPixel = 0;
            //灰度等级数组清零
            Array.Clear(countPixel,0,256);
            //计算各个灰度级的像素个数
            for (int i = 0; i < bytes;i++ )
            {
                //灰度级
                temp=graybValues[i];
                //计数加1
                countPixel[temp]++;
                if(countPixel[temp]>maxPixel)
                {
                    //找到灰度频率最大的像素数，用于绘制直方图
                    maxPixel=countPixel[temp];
                }
            }
            //解锁
            System.Runtime.InteropServices.Marshal.Copy(graybValues,0,ptr,bytes);
            bmpHist.UnlockBits(bmpData);
        }