/// <summary>
/// 取消异步邮件发送
/// </summary>
public void SendAsyncCancel()
{
// 因为此类为非线程安全类，所以 SendAsyncCancel 和发送邮件方法中操作MessageQueue部分的代码肯定是串行化的。
// 所以不存在一边入队，一边出队导致无法完全取消所有邮件发送
// 1、清空队列。
// 2、取消正在异步发送的mail。
// 3、设置计划数量=完成数量
// 4、执行 AutoDisposeSmtp()
if (m_IsAsync)
{
// 1、清空队列。
MailUserState tempMailUserState = null;
while (MessageQueue.TryDequeue(out tempMailUserState))
{
Interlocked.Decrement(ref m_messageQueueCount);
MailMessage message = tempMailUserState.CurMailMessage;
this.InnerDisposeMessage(message);
}
tempMailUserState = null;
// 2、取消正在异步发送的mail。
m_SmtpClient.SendAsyncCancel();
// 3、设置计划数量=完成数量
PrepareSendCount = CompletedSendCount;
// 4、执行 AutoDisposeSmtp()
this.AutoDisposeSmtp();
}
else
{
throw new Exception(MailValidatorHelper.EMAIL_ASYNC_CALL_ERROR);
}
}
/// <summary>
/// 声明在 SmtpClient.SendAsync() 执行完后释放相关对象的回调方法 最后触发的委托
/// </summary>
protected void SendCompleted4Dispose(object sender, AsyncCompletedEventArgs e)
{
MailUserState state = e.UserState as MailUserState;
if (state.CurMailMessage != null)
{
MailMessage message = state.CurMailMessage;
this.InnerDisposeMessage(message);
state.CurMailMessage = null;
}
if (state.IsSmpleMail)
{
if (state.AutoReleaseSmtp && state.CurSmtpClient != null)
{
#if DEBUG
Debug.WriteLine("释放SmtpClient");
#endif
state.CurSmtpClient.Dispose();
state.CurSmtpClient = null;
}
}
else
{
if (!e.Cancelled) // 取消的就不计数
{
CompletedSendCount++;
}
if (state.AutoReleaseSmtp)
{
this.AutoDisposeSmtp();
}
// 若批量异步发送，需要设置信号
#if DEBUG
Debug.WriteLine("Set" + Thread.CurrentThread.ManagedThreadId);
#endif
AutoResetEvent.Set();
}
// 先释放资源，处理错误逻辑
if (e.Error != null && !state.IsErrorHandle)
{
throw e.Error;
}
}
/// <summary>
/// 发送Email
/// </summary>
private void InnerSendMessage()
{
bool hasError = false;
MailMessage mMailMessage = null;
#region 构建 MailMessage
try
{
mMailMessage = new MailMessage();
mMailMessage.From = new MailAddress(From, FromDisplayName);
this.InnerSetAddress(EmailAddrType.To, mMailMessage);
this.InnerSetAddress(EmailAddrType.CC, mMailMessage);
this.InnerSetAddress(EmailAddrType.Bcc, mMailMessage);
mMailMessage.Subject = Subject;
mMailMessage.Body = Body;
if (m_Attachments != null && m_Attachments.Count > 0)
{
foreach (Attachment attachment in m_Attachments)
{
mMailMessage.Attachments.Add(attachment);
}
}
mMailMessage.SubjectEncoding = Encoding.UTF8;
mMailMessage.BodyEncoding = Encoding.UTF8;
// SmtpClient 的 Headers 中会根据 MailMessage 默认设置些值，所以应该为 UTF8 。
mMailMessage.HeadersEncoding = Encoding.UTF8;
mMailMessage.IsBodyHtml = IsBodyHtml;
if (m_AlternateViews != null && m_AlternateViews.Count > 0)
{
foreach (AlternateView alternateView in AlternateViews)
{
mMailMessage.AlternateViews.Add(alternateView);
}
}
mMailMessage.Priority = (MailPriority)Priority;
}
catch (ArgumentNullException argumentNullEx)
{
hasError = true;
throw argumentNullEx;
}
catch (ArgumentException argumentEx)
{
hasError = true;
throw argumentEx;
}
catch (FormatException formatEx)
{
hasError = true;
throw formatEx;
}
finally
{
if (hasError)
{
if (mMailMessage != null)
{
this.InnerDisposeMessage(mMailMessage);
mMailMessage = null;
}
this.InnerDisposeSmtp();
}
}
#endregion
if (!hasError)
{
if (m_IsAsync)
{
#region 异步发送邮件
if (PrepareSendCount == 1)
{
// 情况一：不重用 SmtpClient 实例会将PrepareSendCount设置为1
// 情况二：计划发送只有一条
// PrepareSendCount 是发送单条邮件。
MailUserState state = new MailUserState()
{
AutoReleaseSmtp = m_autoDisposeSmtp,
CurMailMessage = mMailMessage,
CurSmtpClient = m_SmtpClient,
IsSmpleMail = true,
UserState = AsycUserState,
};
if (m_autoDisposeSmtp)
{
// 由发送完成回调函数根据 IsSmpleMail 字段进行释放
m_SmtpClient = null;
}
ThreadPool.QueueUserWorkItem((userState) =>
{
// 无需 catch 发送异常，因为是异步，所以这里 catch 不到。
MailUserState curUserState = userState as MailUserState;
curUserState.CurSmtpClient.SendAsync(mMailMessage, userState);
}, state);
}
else
{
// 情况一：重用 SmtpClient 逻辑，即我们可以直接操作全局的 m_SmtpClient
// 情况二：批量发送邮件 PrepareSendCount>1
// 情况三：PrepareSendCount 还未设置，为0。比如场景在循环中做些判断，再决定发邮件，循环完才调用 SetBatchMailCount 设置计划邮件数量
MailUserState state = new MailUserState()
{
AutoReleaseSmtp = m_autoDisposeSmtp,
CurMailMessage = mMailMessage,
CurSmtpClient = m_SmtpClient,
UserState = AsycUserState,
};
MessageQueue.Enqueue(state);
Interlocked.Increment(ref m_messageQueueCount);
if (m_SendMailThread == null)
{
m_SendMailThread = new Thread(() =>
{
// noItemCount 次获取不到元素，就抛出线程异常
int noItemCount = 0;
while (true)
{
if (PrepareSendCount != 0 && PrepareSendCount == CompletedSendCount)
{
// 已执行完毕。
this.AutoDisposeSmtp();
break;
}
else
{
MailUserState curUserState = null;
if (!MessageQueue.IsEmpty)
{
#if DEBUG
Debug.WriteLine("WaitOne" + Thread.CurrentThread.ManagedThreadId);
#endif
// 当执行异步取消时，会清空MessageQueue，所以 WaitOne 必须在从MessageQueue中取到元素之前
AutoResetEvent.WaitOne();
if (MessageQueue.TryDequeue(out curUserState))
{
Interlocked.Decrement(ref m_messageQueueCount);
m_SmtpClient.SendAsync(curUserState.CurMailMessage, curUserState);
}
}
else
{
if (noItemCount >= 10)
{
// 没有正确设置 PrepareSendCount 值。导致已没有邮件但此线程出现死循环
this.InnerDisposeSmtp();
throw new Exception(MailValidatorHelper.EMAIL_PREPARESENDCOUNT_NOTSET_ERROR);
}
Thread.Sleep(1000);
noItemCount++;
}
}
// SmtpClient 为null表示异步预计发送邮件数已经发送完，在 OnSendCompleted 进行了 m_SmtpClient 释放
if (m_SmtpClient == null)
{
break;
}
}
m_SendMailThread = null;
});
m_SendMailThread.Start();
}
}
#endregion
}
else
{
#region 步发送邮件
try
{
m_SmtpClient.Send(mMailMessage);
m_CompletedSendCount++;
}
catch (ObjectDisposedException smtpDisposedEx)
{
throw smtpDisposedEx;
}
catch (InvalidOperationException smtpOperationEx)
{
throw smtpOperationEx;
}
catch (SmtpFailedRecipientsException smtpFailedRecipientsEx)
{
throw smtpFailedRecipientsEx;
}
catch (SmtpException smtpEx)
{
throw smtpEx;
}
finally
{
if (mMailMessage != null)
{
this.InnerDisposeMessage(mMailMessage);
mMailMessage = null;
}
this.AutoDisposeSmtp();
}
#endregion
}
}
}