c# - 代码检查说我需要处理对象。哪一个？

Question

这是我的功能。我已经将客户端和消息都包装到 using 子句中，并且在运行代码检查时仍然出现错误。错误指向首先使用行：

public static void Send(MailItem mail)
        {
            var sender = Membership.GetUser(mail.CreatedBy);
            if (sender == null)
            {
                return;
            }

            using (var msg = new MailMessage { From = new MailAddress(ConfigurationManager.AppSettings["EmailSender"], ConfigurationManager.AppSettings["EmailSenderName"]) })
            {
                foreach (var recipient in mail.MailRecipients)
                {
                    var recipientX = Membership.GetUser(recipient.UserKey);
                    if (recipientX == null)
                    {
                        continue;
                    }

                    msg.To.Add(new MailAddress(recipientX.Email, recipientX.UserName));
                }

                msg.Subject = "[From: " + sender.UserName + "]" + mail.Subject;
                msg.Body = mail.Body;

                if (HttpContext.Current != null)
                {
                    msg.Body += Environment.NewLine + Environment.NewLine + "To reply via Web click link below:" +
                                Environment.NewLine;
                    msg.Body += ConfigurationManager.AppSettings["MailPagePath"] + "?AID=" +
                                ContextManager.CurrentAccount.AccountId + "&RUN=" + sender.UserName;
                }

                try
                {
                    using (var emailClient = new SmtpClient())
                    {
                        emailClient.Send(msg);
                    }
                }
                catch (Exception ex)
                {
                    Logger.LogException(ex);
                }
            }
        }

这是我得到的警告：

警告 1 CA2000：Microsoft.Reliability：在方法“Email.Send(MailItem)”中，对象“<> g_initLocal0”并未沿所有异常路径处理。在对对象“<>g _initLocal0”的所有引用超出范围之前调用 System.IDisposable.Dispose。C:\CodeWorkspace\Code\Utility\Email.cs 41

Answer 1

你的问题是这一行：

using (var msg = new MailMessage { From = new MailAddress(ConfigurationManager.AppSettings["EmailSender"], ConfigurationManager.AppSettings["EmailSenderName"]) }) 

初始化程序块{ From = ... }在对象被构造之后和using块的内部try/finally开始之前执行。

如果MailAddress构造函数（或其参数表达式，或者From如果它是属性访问器的赋值）抛出异常，MailMessage则不会被释放。

改成：

using (var msg = new MailMessage()) 
{
    msg.From = new MailAddress(ConfigurationManager.AppSettings["EmailSender"], ConfigurationManager.AppSettings["EmailSenderName"]);
    ...
}

临时<>g_initLocal0变量是 MailMessage 在分配给 之前的名称msg。