有没有简单的方法将 System.Net.Mail.MailMessage 对象转换为原始的邮件消息文本,就像在记事本中打开 eml 文件那样。
这是同样的解决方案,但作为MailMessage
的扩展方法。
在静态上下文中一次性获取ConstructorInfo
和MethodInfo
成员可以最小化一些反射开销。
/// <summary>
/// Uses reflection to get the raw content out of a MailMessage.
/// </summary>
public static class MailMessageExtensions
{
private static readonly BindingFlags Flags = BindingFlags.Instance | BindingFlags.NonPublic;
private static readonly Type MailWriter = typeof(SmtpClient).Assembly.GetType("System.Net.Mail.MailWriter");
private static readonly ConstructorInfo MailWriterConstructor = MailWriter.GetConstructor(Flags, null, new[] { typeof(Stream) }, null);
private static readonly MethodInfo CloseMethod = MailWriter.GetMethod("Close", Flags);
private static readonly MethodInfo SendMethod = typeof(MailMessage).GetMethod("Send", Flags);
/// <summary>
/// A little hack to determine the number of parameters that we
/// need to pass to the SaveMethod.
/// </summary>
private static readonly bool IsRunningInDotNetFourPointFive = SendMethod.GetParameters().Length == 3;
/// <summary>
/// The raw contents of this MailMessage as a MemoryStream.
/// </summary>
/// <param name="self">The caller.</param>
/// <returns>A MemoryStream with the raw contents of this MailMessage.</returns>
public static MemoryStream RawMessage(this MailMessage self)
{
var result = new MemoryStream();
var mailWriter = MailWriterConstructor.Invoke(new object[] { result });
SendMethod.Invoke(self, Flags, null, IsRunningInDotNetFourPointFive ? new[] { mailWriter, true, true } : new[] { mailWriter, true }, null);
result = new MemoryStream(result.ToArray());
CloseMethod.Invoke(mailWriter, Flags, null, new object[] { }, null);
return result;
}
}
为了获取底层的MemoryStream
:var email = new MailMessage();
using (var m = email.RawMessage()) {
// do something with the raw message
}
var message = (MimeMessage) CreateSystemNetMailMessage ();
using (var stream = File.Create ("C:\\message.eml"))
message.WriteTo (stream);
private static MemoryStream ConvertMailMessageToMemoryStream(MailMessage message)
{
BindingFlags flags = BindingFlags.Instance | BindingFlags.NonPublic;
Assembly assembly = typeof(SmtpClient).Assembly;
MemoryStream stream = new MemoryStream();
Type mailWriterType = assembly.GetType("System.Net.Mail.MailWriter");
ConstructorInfo mailWriterContructor = mailWriterType.GetConstructor(flags, null, new[] { typeof(Stream) }, null);
object mailWriter = mailWriterContructor.Invoke(new object[] { stream });
MethodInfo sendMethod = typeof(MailMessage).GetMethod("Send", flags);
sendMethod.Invoke(message, flags, null, new[] { mailWriter, true }, null);
MethodInfo closeMethod = mailWriter.GetType().GetMethod("Close", flags);
closeMethod.Invoke(mailWriter, flags, null, new object[] { }, null);
return stream;
}
MemoryStream
转换成字符串或者其他需要的格式。byte[] allBytes = new byte[attachment.ContentStream.Length];
int bytesRead = attachment.ContentStream.Read(allBytes, 0, (int)attachment.ContentStream.Length);
Encoding encoding = Encoding.UTF8;
String contenidoCorreo = encoding.GetString(allBytes);
Send
的附加参数下)在你的电脑上的 .NET 4.5 版本中能否正常工作?在调用CloseMethod
之前,我不得不将result
的内容复制到另一个MemoryStream
中,因为当前的实现实际上会关闭底层流。 - hangy