为什么 一运行直方图就死机呢，请帮助

Question

​代码：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;namespace WindowsFormsApplication6
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private System.Drawing.Bitmap curMap;        private void openImage_Click(object sender, EventArgs e)
        {
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                curMap = new Bitmap(openFileDialog1.FileName);
                pictureBox1.Image = curMap;            }
        }        private void button1_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();
            Pen curPen = new Pen(Brushes.Black, 1);
            g.DrawLine(curPen, 50, 240, 320, 240);
            g.DrawLine(curPen, 50, 240, 50, 30);
            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.DrawString("0", new Font("New Timer", 8), Brushes.Black, new PointF(46, 242));
            g.DrawString("0", new Font("New Timer", 8), Brushes.Black, new PointF(34, 234));
            g.DrawLine(curPen, 48, 40, 50, 40);
            g.DrawString("0", new Font("New Timer", 8), Brushes.Black, new PointF(46, 242));
            Rectangle rect = new Rectangle(0,0,curMap.Width,curMap.Height);
            System.Drawing.Imaging.BitmapData bmpData = curMap.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadWrite, curMap.PixelFormat);
            int  bytes = bmpData.Width * bmpData.Height;
            byte[] grayValue = new byte[bytes];
            IntPtr ptr = bmpData.Scan0;
            System.Runtime.InteropServices.Marshal.Copy(ptr, grayValue, 0, bytes);
            byte temp = 0 ;
            int maxPixel = 0;
            int[] countPixle =new int[256];
            Array.Clear(countPixle, 0, 256);
            for (int i = 0; i < bytes; i++)
            {
                temp = grayValue[i];
                countPixle[temp]++;
                if(countPixle[temp]>maxPixel)
                {
                    maxPixel = countPixle[temp];
                }
 
            }
            System.Runtime.InteropServices.Marshal.Copy(grayValue, 0, ptr, bytes);
            g.DrawString("0", new Font("New Timer", 8), Brushes.Black, new PointF(46, 242));
            g.DrawString(maxPixel.ToString(), new Font("New Timer", 8), Brushes.Black, new PointF(18, 34));
            
            for (int i = 0; i < 256; )
            {
                temp = Convert.ToByte(200.0 * countPixle[i] / maxPixel);
                g.DrawLine(curPen, 50 + i, 240, 50 + i, 240 - (int)temp);
            }
            curPen.Dispose();
        }
                
        }
    }
运行完之后：却显示不出来直方图，只显示坐标，、

Answer 1

for (int i = 0; i < 256; )
少了i++