我正在尝试发送带有附加Excel文件名的
HTML电子邮件.这一切都运行良好,直到我发送其附件名称包含重音字母的消息:-(我尝试过的每一种解决方法都失败了.
原始代码：
var attachment = new Attachment(
new MemoryStream(excelFileContents),"simplefilename.xls");
这个工作正常.
但是,如果我用“échec.xls”替换“simplefilename.xls”,附件就会被填充(名称和内容).
我试过这些,但无济于事：
var attachment = new Attachment(
new MemoryStream(excelFileContents),new System.Net.Mime.ContentType("application/vnd.ms-excel"));
attachment.Name = "échec.xls";
最后一个更糟糕：SmtpClient.Send()抛出异常,抱怨文件名中的é：
var attachment = new Attachment(
new MemoryStream(excelFileContents),new System.Net.Mime.ContentType("application/vnd.ms-excel"));
attachment.ContentDisposition.FileName = "échec.xls";
我一直在敲打这个问题太久了.任何灯都热烈欢迎！
解决方法
我终于找到了一个有效的答案.
除了Marcel Roma的帖子外,内容为德语.我将他的代码放入我的应用程序中.我能够发出带有重音的pdf,我们看到了附件而不是垃圾.
所以这里是：
public class AttachmentHelper
{
public static System.Net.Mail.Attachment CreateAttachment(string attachmentFile,string displayName,TransferEncoding transferEncoding)
{
System.Net.Mail.Attachment attachment = new System.Net.Mail.Attachment(attachmentFile);
attachment.TransferEncoding = transferEncoding;
string tranferEncodingMarker = String.Empty;
string encodingMarker = String.Empty;
int maxChunkLength = 0;
switch (transferEncoding)
{
case TransferEncoding.Base64:
tranferEncodingMarker = "B";
encodingMarker = "UTF-8";
maxChunkLength = 30;
break;
case TransferEncoding.QuotedPrintable:
tranferEncodingMarker = "Q";
encodingMarker = "ISO-8859-1";
maxChunkLength = 76;
break;
default:
throw (new ArgumentException(String.Format("The specified TransferEncoding is not supported: {0}",transferEncoding,"transferEncoding")));
}
attachment.NameEncoding = Encoding.GetEncoding(encodingMarker);
string encodingtoken = String.Format("=?{0}?{1}?",encodingMarker,tranferEncodingMarker);
string softbreak = "?=";
string encodedAttachmentName = encodingtoken;
if (attachment.TransferEncoding == TransferEncoding.QuotedPrintable)
encodedAttachmentName = HttpUtility.UrlEncode(displayName,Encoding.Default).Replace("+"," ").Replace("%","=");
else
encodedAttachmentName = System.Convert.ToBase64String(Encoding.UTF8.GetBytes(displayName));
encodedAttachmentName = SplitEncodedAttachmentName(encodingtoken,softbreak,maxChunkLength,encodedAttachmentName);
attachment.Name = encodedAttachmentName;
return attachment;
}
private static string SplitEncodedAttachmentName(string encodingtoken,string softbreak,int maxChunkLength,string encoded)
{
int splitLength = maxChunkLength - encodingtoken.Length - (softbreak.Length * 2);
var parts = SplitByLength(encoded,splitLength);
string encodedAttachmentName = encodingtoken;
foreach (var part in parts)
encodedAttachmentName += part + softbreak + encodingtoken;
encodedAttachmentName = encodedAttachmentName.Remove(encodedAttachmentName.Length - encodingtoken.Length,encodingtoken.Length);
return encodedAttachmentName;
}
private static IEnumerable<string> SplitByLength(string stringToSplit,int length)
{
while (stringToSplit.Length > length)
{
yield return stringToSplit.Substring(0,length);
stringToSplit = stringToSplit.Substring(length);
}
if (stringToSplit.Length > 0) yield return stringToSplit;
}
}
以下列方式使用它：
static void Main(string[] args)
{
string smtpServer = String.Empty;
string userName = String.Empty;
string password = String.Empty;
string attachmentFilePath = String.Empty;
string displayName = String.Empty;
System.Net.Mail.SmtpClient client = new System.Net.Mail.SmtpClient(smtpServer);
client.Credentials = new System.Net.NetworkCredential(userName,password);
var msg = new System.Net.Mail.MailMessage(fromAddress,toAddress,"Subject","Body");
System.Net.Mail.Attachment attachment =
AttachmentHelper.CreateAttachment(attachmentFilePath,displayName,TransferEncoding.Base64);
msg.Attachments.Add(attachment);
client.Send(msg);
}
