Question

我正在尝试找到一种解决方案，以区分Outlook邮件中的嵌入式图像和附件。经过研究后，我发现以下代码适用于大多数情况

foreach (Outlook.Attachment attachment in mailItem.Attachments)
{
    try
    {
        var attachmentType = attachment.FileName.Substring(attachment.FileName.LastIndexOf('.'));
        if (attachmentType!=null&&attachmentType.Trim().Length>1&&_fileTypeFilter.Contains(attachmentType.Substring(1).ToLower()))
        {
            prop=attachment.PropertyAccessor;
            string conentId = (string)prop.GetProperty("http://schemas.microsoft.com/mapi/proptag/0x3712001E");
            if ((attachmentType.Substring(1).ToLower() == "pdf") ||(conentId==null||conentId.Trim().Length==0))

            {          
                //Always allow PDF 
                // This is an attachement
            }
        }
    }
    catch (Exception ex)
    {

    }
}

问题是，当从其他邮件系统发送邮件（例如：hotmail）时，附件的内容ID不为null。这将导致附件被忽略。

我讨厌的另一个建议是根据以下StackFlow don't save embedded

检查该物业

foreach (Outlook.Attachment attachment in mailItem.Attachments)
{
    try
    {
        // var tst = attachment.Type;
        var attachmentType = attachment.FileName.Substring(attachment.FileName.LastIndexOf('.'));
        if (attachmentType!=null&&attachmentType.Trim().Length>1&&_fileTypeFilter.Contains(attachmentType.Substring(1).ToLower()))
        {
            prop=attachment.PropertyAccessor;
            string conentId = (string)prop.GetProperty("http://schemas.microsoft.com/mapi/proptag/0x3712001E");
            var flags = prop.GetProperty("http://schemas.microsoft.com/mapi/proptag/0x37140003"); 

            var asize = attachment.Size;
            if ((attachmentType.Substring(1).ToLower() == "pdf") ||
               (asize>0&&(flags!=4 &&(int)attachment.Type != 6)))  // As per present understanding - If rtF mail attachment comes here - and the embeded image is treated as attachment then Type value is 6 and ignore it
                                                                                             //  (conentId==null||conentId.Trim().Length==0))

            {
              //This is a valid attachment
            }
        }
    }
    catch (Exception ex)
    {

    }
}

但这有时会包含签名中的图像

Answer 1

最可靠的方法是解析HTML正文(MailItem.HTMLBody属性，以提取所有img标签并检查其scr属性。如果其格式为“ cid：xyz”，则“ xyz”将是附件上PR_ATTACH_CONTENT_ID属性的值。它也可以通过文件名来引用图形文件。

Answer 2

这是可行的解决方案

 var selection = explorer.Selection;

            if (selection.Count == 1)
            {
                object selectedItem = selection[1];

                var mailItem = selectedItem as Outlook.MailItem;
                if (mailItem == null) return;


              foreach (Outlook.Attachment attachment in mailItem.Attachments)
                 {

                  bool validAttachment = isAnAttachment(attachment);
                  }       
            }


 private bool isAnAttachment(Outlook.Attachment attachment)
                {
                    bool isValid = false;
                    var attachmentType = attachment.FileName.Substring(attachment.FileName.LastIndexOf('.'));
                    if (attachmentType != null && attachmentType.Trim().Length > 1 && _fileTypeFilter.Contains(attachmentType.Substring(1).ToLower()))
                    {
                        Outlook.PropertyAccessor prop = attachment.PropertyAccessor;

                        var flags = prop.GetProperty("http://schemas.microsoft.com/mapi/proptag/0x37140003");

                        var asize = attachment.Size;
                        // As per present understanding - If rtF mail attachment comes here - and the embeded image is treated as attachmet
                        if ((attachmentType.Substring(1).ToLower() == "pdf") || (asize > 0 && flags != 4 && (int)attachment.Type != 6))
                        {
                            isValid = true;
                        }
                    }
                    return isValid;
                }

在Outlook中区分嵌入式图像和附件

2 个答案: