摘要

在exchange 2007或者2010中获取的邮件内容为html标签格式，也就是一个页面。如果里面含有img标签，你会发现img标签的src属性为cid:xxxxxxxxxxxx的一串字符串，并不是url，这时候就造成页面上图片显示不出来。

解决办法

在网上找了一种解决办法。

原文地址：

首先创建cid的索引

private const string CidPattern = "cid:";private static HashSet
     
       BuildCidIndex(string html){    var index = new HashSet
      
       ();    var pos = html.IndexOf(CidPattern, 0);    while (pos > 0)    {        var start = pos + CidPattern.Length;        index.Add(start);        pos = html.IndexOf(CidPattern, start);    }    return index;}
      
     

在索引的基础上封装一个替换的方法

private static void AdjustIndex(HashSet
     
       index, int oldPos, int byHowMuch){    var oldIndex = new List
      
       (index);    index.Clear();    foreach (var pos in oldIndex)    {        if (pos < oldPos)            index.Add(pos);        else            index.Add(pos + byHowMuch);    }           }private static bool ReplaceCid(HashSet
       
         index, ref string html, string cid, string path){    var posToRemove = -1;    foreach (var pos in index)    {        if (pos + cid.Length < html.Length && html.Substring(pos, cid.Length) == cid)        {            var sb = new StringBuilder();            sb.Append(html.Substring(0, pos-CidPattern.Length));            sb.Append(path);            sb.Append(html.Substring(pos + cid.Length));            html = sb.ToString();            posToRemove = pos;            break;        }    }    if (posToRemove < 0)        return false;    index.Remove(posToRemove);    AdjustIndex(index, posToRemove, path.Length - (CidPattern.Length + cid.Length));    return true;}
       
      
     

在获取的item中获取附件

FileAttachment[] attachments = null;var index = BuildCidIndex(sHTMLCOntent);if (index.Count > 0 && item.Attachments.Count > 0){    var basePath = Directory.GetCurrentDirectory();    attachments = new FileAttachment[item.Attachments.Count];    for (var i = 0; i < item.Attachments.Count; ++i)    {      var type = item.Attachments[i].ContentType.ToLower();      if (!type.StartsWith("image/")) continue;                          type = type.Replace("image/", "");      var attachment = (FileAttachment)item.Attachments[i];      var cid = attachment.ContentId;      var filename = cid + "." + type;      var path = Path.Combine(basePath, filename);      if(ReplaceCid(index, ref sHTMLCOntent, cid, path))      {         // only load images when they have been found                   attachment.Load(path);         attachments[i] = attachment;      }   }}