RaspberryIO_26/Swan/Extensions.MimeMessage.cs
2019-12-04 18:57:18 +01:00

56 lines
2.3 KiB
C#

namespace Swan
{
using System;
using System.IO;
using System.Net.Mail;
using System.Reflection;
/// <summary>
/// Extension methods.
/// </summary>
public static class SmtpExtensions
{
private static readonly BindingFlags PrivateInstanceFlags = BindingFlags.Instance | BindingFlags.NonPublic;
/// <summary>
/// The raw contents of this MailMessage as a MemoryStream.
/// </summary>
/// <param name="this">The caller.</param>
/// <returns>A MemoryStream with the raw contents of this MailMessage.</returns>
public static MemoryStream ToMimeMessage(this MailMessage @this)
{
if (@this == null)
throw new ArgumentNullException(nameof(@this));
var result = new MemoryStream();
var mailWriter = MimeMessageConstants.MailWriterConstructor.Invoke(new object[] { result });
MimeMessageConstants.SendMethod.Invoke(
@this,
PrivateInstanceFlags,
null,
MimeMessageConstants.IsRunningInDotNetFourPointFive ? new[] { mailWriter, true, true } : new[] { mailWriter, true },
null);
result = new MemoryStream(result.ToArray());
MimeMessageConstants.CloseMethod.Invoke(
mailWriter,
PrivateInstanceFlags,
null,
Array.Empty<object>(),
null);
result.Position = 0;
return result;
}
internal static class MimeMessageConstants
{
#pragma warning disable DE0005 // API is deprecated
public static readonly Type MailWriter = typeof(SmtpClient).Assembly.GetType("System.Net.Mail.MailWriter");
#pragma warning restore DE0005 // API is deprecated
public static readonly ConstructorInfo MailWriterConstructor = MailWriter.GetConstructor(PrivateInstanceFlags, null, new[] { typeof(Stream) }, null);
public static readonly MethodInfo CloseMethod = MailWriter.GetMethod("Close", PrivateInstanceFlags);
public static readonly MethodInfo SendMethod = typeof(MailMessage).GetMethod("Send", PrivateInstanceFlags);
public static readonly bool IsRunningInDotNetFourPointFive = SendMethod.GetParameters().Length == 3;
}
}
}