我不知道为什么我会收到这个错误。似乎基本。无论如何,我有一个叫做EmailSender的单例类。下面的代码简短易行。问题是我不能在MainWindow类中使用sender。我尝试的任何东西,如sender.Send()被视为我已经完成了asdafsafas.Send()。它被视为随机字符串。不知道为什么会这样。
using System;
using System.Net.Mail;
using System.Windows.Forms;
namespace SendMail
{
public partial class MainWindow : Form
{
#region Private variables
private MailMessage msg = new MailMessage();
private EmailSender sender = EmailSender.GetInstance();
#endregion
public MainWindow()
{
InitializeComponent();
}
private MailMessage PrepareMailMessage()
{
return msg;
}
private void btnSend_Click(object sender, EventArgs e)
{
}
}
}
以下是GetInstance方法:
public static EmailSender GetInstance()
{
return _instance ?? (_instance = new EmailSender());
}
答案 0 :(得分:6)
这是因为你定义了这个方法的方式(sender是一个参数)。它找到方法参数 first ,而不是类级变量。你可以证明这一点:
private void btnSend_Click(object sender, EventArgs e)
{
// sender here is the "(object sender, " paramater, so it's defined
// as system object.
// use this instead:
this.sender.Send(); // The "this" will make the class find the instance level variable instead of using the "object sender" argument
}
答案 1 :(得分:1)
那是因为sender
不是邮件对象,而是触发事件的按钮。您需要SmtpClient
发送电子邮件:
private void btnSend_Click(object sender, EventArgs e)
{
SmtpClient client = new SmtpClient("192.0.0.1", 25); //host, port
client.Send(msg);
}
此外,MailMessage
类实现了IDisposable
,因此一旦完成,您需要一些代码来处理消息。
我创建了一个包装器,其中包含发送电子邮件所需的所有内容,包括处理:
/// <summary>
/// Wrapper class for the System.Net.Mail objects
/// </summary>
public class SmtpMailMessage : IDisposable
{
#region declarations
MailMessage Message;
SmtpClient SmtpMailClient;
#endregion
#region constructors
/// <summary>
/// Default constructor for the SmtpMailMessage class
/// </summary>
public SmtpMailMessage()
{
//initialize the mail message
Message = new MailMessage();
Message.Priority = MailPriority.Normal;
Message.DeliveryNotificationOptions = DeliveryNotificationOptions.OnFailure;
Message.From = new MailAddress("xxx@abc.com");
//initialize the smtp client
SmtpMailClient = new SmtpClient();
SmtpMailClient.DeliveryMethod = SmtpDeliveryMethod.Network;
SmtpMailClient.Host = "192.168.0.1";
SmtpMailClient.Port = 25;
}
/// <summary>
/// Parameterized constructor for the SmtpMailMessage class. Allows for override of the default
/// SMTP host and port number
/// </summary>
/// <param name="HostIP">The IP address of the exchange server</param>
/// <param name="PortNumber">The port number for ingoing and outgoing SMTP messages</param>
public SmtpMailMessage(string HostIP, int PortNumber) : this()
{
//override the smtp host value
SmtpMailClient.Host = HostIP;
//override the smtp port value
SmtpMailClient.Port = PortNumber;
}
#endregion
#region subject / body
/// <summary>
/// The body content of the mail message
/// </summary>
public string Body
{
get
{
return Message.Body;
}
set
{
Message.Body = value;
}
}
/// <summary>
/// the subject of the mail message
/// </summary>
public string Subject
{
get
{
return Message.Subject;
}
set
{
Message.Subject = value;
}
}
#endregion
#region mail type
/// <summary>
/// Gets or sets a value that determines whether the mail message
/// should be formatted as HTML or text
/// </summary>
public bool IsHtmlMessage
{
get
{
return Message.IsBodyHtml;
}
set
{
Message.IsBodyHtml = value;
}
}
#endregion
#region sender
/// <summary>
/// Gets or sets the from address of this message
/// </summary>
public string From
{
get
{
return Message.From.Address;
}
set
{
Message.From = new MailAddress(value);
}
}
#endregion
#region recipients
/// <summary>
/// Gets the collection of recipients
/// </summary>
public MailAddressCollection To
{
get
{
return Message.To;
}
}
/// <summary>
/// Gets the collection of CC recipients
/// </summary>
public MailAddressCollection CC
{
get
{
return Message.CC;
}
}
/// <summary>
/// Gets the collection of Bcc recipients
/// </summary>
public MailAddressCollection Bcc
{
get
{
return Message.Bcc;
}
}
#endregion
#region delivery notification
/// <summary>
/// Gets or sets the delivery notification settings for this message
/// </summary>
public DeliveryNotificationOptions DeliveryNotifications
{
get
{
return Message.DeliveryNotificationOptions;
}
set
{
Message.DeliveryNotificationOptions = value;
}
}
#endregion
#region priority
/// <summary>
/// Gets or sets the Priority of this message
/// </summary>
public MailPriority PriorityLevel
{
get
{
return Message.Priority;
}
set
{
Message.Priority = value;
}
}
#endregion
#region send methods
/// <summary>
/// Sends the message anonymously (without credentials)
/// </summary>
public void Send()
{
SmtpMailClient.Send(Message);
}
/// <summary>
/// Sends the message with authorization from a network account
/// </summary>
/// <param name="Username">The Windows username of the authorizing user</param>
/// <param name="Password">The Windows password of the authorizing user</param>
/// <param name="Domain">The domain name of the network to which the authorizing user belongs</param>
public void Send(string Username, string Password, string Domain)
{
//attach a network credential to this message using the information passed into the method
SmtpMailClient.Credentials = new NetworkCredential(Username, Password, Domain);
//send the message
SmtpMailClient.Send(Message);
}
#endregion
#region IDisposable implementation
~SmtpMailMessage()
{
Dispose(false);
}
public void Dispose()
{
Dispose(true);
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
if (Message != null)
Message.Dispose();
Message = null;
SmtpMailClient = null;
}
}
#endregion
}
实现:
using (SmtpMailMessage mail = new SmtpMailMessage("192.168.0.1", 25))
{
//set the to address to the primary email
mail.To.Add("xxx@abc.com");
//set the message type and subject and body
mail.IsHtmlMessage = true;
mail.Subject = "Foo";
mail.Body = "Hello world!";
//send the email
mail.Send();
}
答案 2 :(得分:0)
如果您在btnSend_Click
方法的范围内执行此操作,则参数object sender
优先于全局EmailSender sender
。
您应该重命名全局变量,例如:EmailSender m_sender
或准确指定所需的发件人:this.sender.Send()
答案 3 :(得分:0)
我猜你叫发送者。发送到btnSend_Click函数。
在该函数中是一个名为sender(对象发送者)的param。现在你的代码混淆了哪一个使用。所以重命名你的私人var发送者。