长度不能小于零 参数名称：length

Question

我一直在寻找解决这个错误的方法。在 VS2015 的调试和发布模式下，我没有收到任何错误，并且代码会生成所需的结果。一旦程序被编译和安装，当按下电子邮件按钮生成代码时，应用程序就像它开始工作一样，然后在大约 20 秒后给出错误“长度不能小于零参数名称：长度”但是应用程序继续，但未完成相关代码。

我已禁用并尝试引用长度的一行代码，这没有任何区别。

我对可能导致这种情况的原因有限，所以我正在寻求帮助以在大海捞针。

下面是有问题的代码：

try
        {
            // Create the Outlook application.
            Microsoft.Office.Interop.Outlook.Application oApp = new Microsoft.Office.Interop.Outlook.Application();
            // Create a new mail item.
            Microsoft.Office.Interop.Outlook.MailItem oMsg = (Microsoft.Office.Interop.Outlook.MailItem)oApp.CreateItem(Microsoft.Office.Interop.Outlook.OlItemType.olMailItem);
            // Set HTMLBody. 
            //add the body of the email
            oMsg.HTMLBody = DictMailParam["Body"].ToString();
            //Add an attachment.
            String sDisplayName = DictMailParam["AttachmentName"].ToString();
            int iPosition = (int)oMsg.Body.Length + 1;
            int iAttachType = (int)Microsoft.Office.Interop.Outlook.OlAttachmentType.olByValue;
            //now attached the file
            //Microsoft.Office.Interop.Outlook.Attachment oAttach = oMsg.Attachments.Add
            //                             (@"C:\\fileName.jpg", iAttachType, iPosition, sDisplayName);

            foreach (string strFile in DictMailParam["Attachments"].ToString().Split(',').ToList())
            {
                Microsoft.Office.Interop.Outlook.Attachment oAttach = oMsg.Attachments.Add
                        (strFile, iAttachType, iPosition, sDisplayName);
            }
            //Subject line
            oMsg.Subject = DictMailParam["Subject"].ToString();
            // Add a recipient.
            Microsoft.Office.Interop.Outlook.Recipients oRecips = (Microsoft.Office.Interop.Outlook.Recipients)oMsg.Recipients;
            Microsoft.Office.Interop.Outlook.Recipient oRecip = null; 
            // Change the recipient in the next line if necessary.
            foreach (var MailId in DictMailParam["ToAddress"].ToString().Split(';').ToArray())
            {
                if (!string.IsNullOrEmpty(MailId))
                {
                    oRecip = (Microsoft.Office.Interop.Outlook.Recipient)oRecips.Add(MailId);//DictMailParam["ToAddress"].ToString()
                    oRecip.Resolve();
                    // Send.
                }

            }

            oMsg.Send();
            MessageBox.Show("Purchase Order has been sent to your email." + "\n" + "Please check your mail.", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
            // Clean up.
            oRecip = null;
            oRecips = null;
            oMsg = null;
            oApp = null;
        }//end of try block
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }//end of catch
    }//end of Email Method

Answer 1

将捕获代码更改为 MessageBox.Show(ex.ToString()...) 而不是 ex.Message。这样，当发生错误时，您将收到一条消息，说明哪一行正在引发异常。然后回到这里，告诉它是哪条线。一旦我们知道问题所在，解决您的问题就会容易得多。