抓取图片

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Text.RegularExpressions;
using System.IO;
namespace ImgSnatch
{
    class Program
    {
        static void Main(string[] args)
        {
            Pic_Remote("<img src=http://www.google.cn/images/nav_logo4.png>");
        }
        private static string Pic_Remote(string news_Content)
        {
            string htmlStr = news_Content;
            string nowyymm = DateTime.Now.ToString("yyyy-MM");    //当前年月
            string nowdd = DateTime.Now.ToString("dd"); //当天号数
            string path=string.Format(@"d:\imgSnatch\images\{0}\{1}",nowyymm,nowdd);
            Directory.CreateDirectory(path);
            string returnValue = "";
            returnValue = SaveUrlPics(htmlStr, path, nowyymm, nowdd);
            return returnValue;
        }
        //下载图片到本地
        public static string SaveUrlPics(string strHTML, string path, string nowyymm, string nowdd)
        {
            string[] imgurlAry = GetImgTag(strHTML);
            try
            {
                for (int i = 0; i < imgurlAry.Length; i++)
                {
                    //WebRequest req = WebRequest.Create(imgurlAry[i]);
                    string preStr = System.DateTime.Now.ToString() + "_";
                    preStr = preStr.Replace("-", "");
                    preStr = preStr.Replace(":", "");
                    preStr = preStr.Replace(" ", "");
                    WebClient wc = new WebClient();
                    wc.DownloadFile(imgurlAry[i], path + "/" + preStr + imgurlAry[i].Substring(imgurlAry[i].LastIndexOf("/") + 1));
                    //替换原图片地址
                    string imgPath = "/Files/Remoteupfile/" + nowyymm + "/" + nowdd;
                    strHTML = strHTML.Replace(imgurlAry[i], imgPath + "/" + preStr + imgurlAry[i].Substring(imgurlAry[i].LastIndexOf("/") + 1));
                }
            }
            catch (Exception ex)
            {
                //return ex.Message;
            }
            return strHTML;
        }

        //获取图片标志
        private static  string[] GetImgTag(string htmlStr)
        {
            Regex regObj = new Regex("<img.+?>", RegexOptions.Compiled | RegexOptions.IgnoreCase);
            string[] strAry = new string[regObj.Matches(htmlStr).Count];
            int i = 0;
            foreach (Match matchItem in regObj.Matches(htmlStr))
            {
                strAry[i] = GetImgUrl(matchItem.Value);
                i++;
            }
            return strAry;
        }
        //获取图片URL地址
        private static  string GetImgUrl(string imgTagStr)
        {
            string str = "";
            Regex regObj = new Regex("http://.+.(?:jpg|gif|bmp|png)", RegexOptions.Compiled | RegexOptions.IgnoreCase);
            foreach (Match matchItem in regObj.Matches(imgTagStr))
            {
                str = matchItem.Value;
            }
            return str;
        }
    }
}