c#之发送电子邮件后代码挂起，但电子邮件发送正常(静态异步任务)

我正在编写一些 C# 代码来发送电子邮件(通过 Mailjet/Azure)。它确实发送了电子邮件，但由于某种原因，在单步执行代码时我从未通过这行代码....

MailjetResponse response = await client.PostAsync(request); 

它只是在那个时候挂起。知道为什么吗？同样，邮件发送成功!

  public static async Task<bool> SendEmailWithAttachment(string toAddress, string subject, string messageBody, bool sendBCCYesNo, bool sendFromInfoAddressYesNo, MemoryStream attachment = null, string attachmentFilename = null) 
    { 
        bool successYesNo = true; 
 
        try 
        { 
            MailjetClient client = new MailjetClient("xxxxxx", "xxxxx") 
            { 
                Version = ApiVersion.V3_1, 
            }; 
            MailjetRequest request = new MailjetRequest 
                { 
                    Resource = Send.Resource, 
                } 
                .Property(Send.Messages, new JArray { 
                    new JObject { 
                        {"From", new JObject { 
                            {"Email", "xxxxx@xxxxx.com"}, 
                            {"Name", "xxxxx"} 
                        }}, 
                        {"To", new JArray { 
                            new JObject { 
                                {"Email", toAddress}, 
                                {"Name", toAddress} 
                            } 
                        }}, 
                        {"Subject", subject}, 
                        {"TextPart", messageBody}, 
                        {"HTMLPart", messageBody} 
                    } 
                }); 
            MailjetResponse response = await client.PostAsync(request); 
            if (response.IsSuccessStatusCode) // I never get to this point 
            { 
              : 

我正在使用这个调用代码....

        if (Utility.SendEmailWithAttachment("xxxxx@xxxxx.com", "Test Email", "Test Body", false, false, 
                po, "AAA.pdf").Result == false) 
        { 
            lblStatus.Text = "Email send failure. Please contact support."; 
            return false; 
        } 

有趣的是，当我运行示例 mailjet 提供的代码时，我的电子邮件发送正常并且我确实到达了 PostAsync 之后的行。据我所知，唯一的主要区别是我使用的是返回 bool 值的任务，而不仅仅是任务。这是 mailjet 提供的工作正常的代码....

    static void Main(string[] args) 
    { 
        RunAsync().Wait(); 
    } 
    static async Task RunAsync() 
    { 
        MailjetClient client = new MailjetClient("xxxx", "xxxx") 
        { 
            Version = ApiVersion.V3_1, 
        }; 
        MailjetRequest request = new MailjetRequest 
            { 
                Resource = Send.Resource, 
            } 
            .Property(Send.Messages, new JArray { 
                new JObject { 
                    {"From", new JObject { 
                        {"Email", "xxxx@xxxx.com"}, 
                        {"Name", "xxxx"} 
                    }}, 
                    {"To", new JArray { 
                        new JObject { 
                            {"Email", "xxxx@xxxx.com"}, 
                            {"Name", "xxxx"} 
                        } 
                    }}, 
                    {"Subject", "Your email flight plan!"}, 
                    {"TextPart", "Dear passenger 1, welcome to Mailjet! May the delivery force be with you!"}, 
                    {"HTMLPart", "<h3>Dear passenger 1, welcome to <a href='https://www.mailjet.com/'>Mailjet</a>!</h3><br />May the delivery force be with you!"} 
                } 
            }); 
        MailjetResponse response = await client.PostAsync(request); 
        if (response.IsSuccessStatusCode) // this line is reached! 
        { 

提前致谢!

请您参考如下方法:

试试下面的代码。一个好的经验法则是不要使用 *.Result 除非先等待。

if ((await Utility.SendEmailWithAttachment("xxxxx@xxxxx.com", "Test Email", "Test Body", false, false, 
            po, "AAA.pdf")) == false) 
{ 
    lblStatus.Text = "Email send failure. Please contact support."; 
    return false; 
}