C# 下载图片到本地

先建立一个类文件，然后建立函数，调用它就可以下载图片。using System;using System.Collections.Generic;using System.Text;using System.IO;using System.Net;using System.Text.RegularExpressions;using System.Windows.Forms;namespace Spider{    class DocumentWorker    {        /// <summary>        /// Download a page        /// </summary>        /// <returns>The data downloaded from the page</returns>             public void saveimage()        {            WebClient mywebclient = new WebClient();            string url = "http://images.google.cn/intl/zh-CN_ALL/images/images_hp.gif";            string newfilename = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() +  DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + ".jpg";            string filepath = @"F:\" + newfilename;            try            {                mywebclient.DownloadFile(url, filepath);                //filename = newfilename;            }            catch (Exception ex)            {                MessageBox.Show(ex.ToString());            }        }    }}