用于下载HTML中远程图片的方法

 

using  System;
using  System.Collections.Generic;
using  System.Text.RegularExpressions;
using  System.Net;
using  System.IO;

namespace  EFPlatform.Common.Helper
... {
    public class WebRequestHelper
    ...{
        RequestFileFromHtml#region RequestFileFromHtml
        public static string RequestFileFromHtml(string html, string fileUrl, string filePath, string reservedHost)
        ...{
            Uri url;
            string fileExt;
            string fileName;
            WebClient c = new WebClient();
            string p = @"((http|https|ftp):(//|//){1}(([A-Za-z0-9_-])+[.]){1,}(net|com|cn|org|cc|tv|[0-9]{1,3})(S*/)((S)+[.]{1}(gif|jpg|png)))";
            Regex r = new Regex(p, RegexOptions.Compiled | RegexOptions.IgnoreCase);
            MatchCollection mc = r.Matches(html);

            if(mc.Count > 0)
            ...{
                List<Uri> urlList = new List<Uri>();
                int matchIndex = 0;
                bool repeated = false;

                for(int i = 0;i < mc.Count;i++)
                ...{
                    url = new Uri(mc[i].Value);

                    for(int j = 0;j < urlList.Count;j++)
                    ...{
                        if(url == urlList[j])
                        ...{
                            repeated = true;
                            break;
                        }
                    }

                    if(!repeated && (url.Host.ToLower() != reservedHost.ToLower()))
                    ...{
                        urlList.Add(url);
                        matchIndex++;
                    }
                }

                for(int i = 0;i < urlList.Count;i++)
                ...{
                    url = urlList[i];
                    fileExt = url.AbsoluteUri.Substring(url.AbsoluteUri.LastIndexOf("."));
                    fileName = string.Format("{0:yyMMddHHmmssff}{1}{2}", DateTime.Now, i, fileExt);

                    try
                    ...{
                        c.DownloadFile(url, filePath + fileName);
                        html = html.Replace(url.AbsoluteUri, fileUrl + fileName);
                    }
                    catch
                    ...{
                    }
                }
            }

            return html;
        } 
        #endregion
    }

}