获取网络图片验证码转换字节流保存本地并显示

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace _0922
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //将服务器上图片保存本地
            string url = string.Format("https://kyfw.12306.cn/otn/passcodeNew/getPassCodeNew?module=regist&rand=sjrand&0.5173300584942714");
            //创建一个request 同时可以配置requst其余属性

            System.Net.WebRequest imgRequst = System.Net.WebRequest.Create(url);
            //在这里我是以流的方式保存图片

            System.Drawing.Image downImage = System.Drawing.Image.FromStream(imgRequst.GetResponse().GetResponseStream());

            string dertory = "C:\test\";

            string fileName = string.Format("{0}.jpg", DateTime.Now.ToString("HHmmssffff"));

            if (!System.IO.Directory.Exists(dertory))
            {

                System.IO.Directory.CreateDirectory(dertory);
            }

            downImage.Save(dertory + fileName,System.Drawing.Imaging.ImageFormat.Jpeg);

            downImage.Dispose();

            this.pictureBox1.Image = Image.FromFile(dertory+fileName);
           


        }
       



    }
}