获取网页中的图片并显示出来代码,Asp.Net代码库,德仔网

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【Asp.Net】获取网页中的图片并显示出来
作者:Dezai.CN / 发布于2012/2/20/ 464
此类实现以下功能： 1、读取网页内容 2、读取网页中的图片，并出来图片的路径 3、剔除重复的图片，并显示。
<div>public class img
{
 public string url = "";
 MatchCollection matches = null;
 public img(string URL)
 {
 url = URL;
 if (url.IndexOf("http://") < 0)
 {
 url = "http://" + url;
 }
 // 获取网页内容
 WebRequest request = WebRequest.Create(url);
 request.Credentials = CredentialCache.DefaultCredentials;
 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
 Stream dataStream = response.GetResponseStream();
 StreamReader reader = new StreamReader(dataStream, Encoding.Default);
 string getHtml = reader.ReadToEnd();
 reader.Close();
 dataStream.Close();
 response.Close();</div>
<div> // 定义正则表达式用来匹配 img 标签
 Regex regImg = new Regex(@"<img/b[^<>]*?/bsrc[/s/t/r/n]*=[/s/t/r/n]*[""']?[/s/t/r/n]*(?<imgUrl>[^/s/t/r/n""'<>]*)[^<>]*?/?[/s/t/r/n]*>", RegexOptions.IgnoreCase);
 // 搜索匹配的字符串
 matches = regImg.Matches(getHtml);
 }
 public string getList()
 {
 StringBuilder sb = new StringBuilder(url);
 if (matches.Count > 0)
 {
 ArrayList al = cutCF(matches, "imgUrl");
 sb.Append(" 获取图片数目：" + al.Count + " 个");
 string mig = "";
 int count = 0;
 foreach (string mc in al)
 {
 string ximg = getImgUrl(mc.ToString());
 if (ximg != "")
 {
 if (mig != ximg)
 {
 count++;
 mig = ximg;
 sb.Append("<img src="/" mce_src="/""" + mig + "/"/>");
 }
 }
 else
 {
 ximg = getImgUrl(url, mc.ToString());
 if (mig != ximg)
 {
 count++;
 mig = ximg;
 sb.Append("<img src="/" mce_src="/""" + mig + "/"/>");
 }
 //WebClient wc = new WebClient();
 //wc.DownloadFile(mc.Groups["imgUrl"].Value, HttpContext.Current.Server.MapPath("img") + "/" + i++ + mc.Groups["imgUrl"].Value.Substring(mc.Groups["imgUrl"].Value.LastIndexOf("/") + 1));
 }
 }
 sb.Append("显示出图片数目：" + count + " 个");
 }
 else
 {
 sb.Append("没找到图片！");
 }
 return sb.ToString();
 }
 /// <summary>
 /// 根据网页地址获取域名
 /// </summary>
 /// <param name="strHtmlPagePath"></param>
 /// <returns></returns>
 public string GetUrlDomainName(string strHtmlPagePath)
 {
 string p = @"<a href="http://[^/.]*/.(?<domain>[^/">http://[^/.]*/.(?<domain>[^/</a>]*)";
 Regex reg = new Regex(p, RegexOptions.IgnoreCase);
 Match m = reg.Match(strHtmlPagePath);
 return m.Groups["domain"].Value;
 }
 /// <summary>
 /// 得到绝对路径的图片url 如果是相对路径 则返回空
 /// </summary>
 /// <param name="imgStr"></param>
 /// <returns></returns>
 private string getImgUrl(string imgStr)
 {
 string str = "";
 Regex reg = new Regex(@"<a href="http://.+.([^/">http://.+.([^/</a>]*)", RegexOptions.Compiled | RegexOptions.IgnoreCase);
 foreach (Match mc in reg.Matches(imgStr))
 {
 str = mc.Value;
 }
 return str;
 }
 /// <summary>
 /// 由图片的相对路径获取全路径
 /// </summary>
 /// <param name="url">网址</param>
 /// <param name="imgstr">图片的相对路径</param>
 /// <returns>全路径</returns>
 private string getImgUrl(string url, string imgstr)
 {
 //获取网址中域名部分
 string ym = url.Replace("http://", "_?");
 string yuming = "http://" + (ym + "/").Substring((ym + "/").IndexOf("_?") + 2, (ym + "/").IndexOf("/") - 1);
 string str = "";
 //如果图片的路径是
 if (imgstr.IndexOf("/") == 0)
 {
 str = yuming + imgstr.Substring(1, imgstr.Length - 1);
 return str;
 }
 if (imgstr.IndexOf("../") == 1)
 {
 str = "http://" + ym.Substring(ym.IndexOf("_?") + 2, ym.LastIndexOf("/") - 1) + imgstr.Substring(1, imgstr.Length - 1);
 return str;
 }
 str = yuming + imgstr;
 return str;
 }
 /// <summary>
 /// 清除重复记录
 /// </summary>
 /// <param name="mc"></param>
 /// <param name="value"></param>
 /// <returns></returns>
 private ArrayList cutCF(MatchCollection mc, string value)
 {
 ArrayList al = new ArrayList();
 string newStr = "";
 if (mc.Count > 0)
 {
 for (int j = 0; j < mc.Count - 1; j++)
 {
 newStr = mc[j].Groups[value].Value;
 bool mkbl = false;
 for (int i = j + 1; i < mc.Count; i++)
 {
 if (newStr == mc[i].Groups[value].Value)
 {
 mkbl = true;
 break;
 }
 }
 if (!mkbl)
 {
 al.Add(mc[j].Groups[value].Value);
 }
 }
 al.Add(mc[mc.Count - 1].Groups[value].Value);
 }
 return al;
 }
}
</div>
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