c# - VB.NET 从收件箱中获取电子邮件的程序

Question

可能重复：
关于 .NET 组件访问电子邮件收件箱的建议

我正在尝试开发一个应用程序来解析电子邮件。我用 PHP 编写了那个程序。它现在正在工作。但问题是我无法完成我的要求。现在我尝试在 VB.NET 或 Visual Studio 支持的任何类型的语言中执行此操作。我的实际要求是获取电子邮件和电子邮件中包含的链接。

如果可能，将不胜感激示例代码。

Answer 1

您可以从查看http://www.codeproject.com/KB/IP/despop3client.aspx开始。如果您需要 SSL（例如 Gmail） - 那么这里有一个示例。我是前段时间写的，它是基于我在网上找到的一些代码。（抱歉不记得在哪里 - 所以没有归属）

public class Pop3EMail
{
    public long Number { get; set; }
    public long Bytes { get; set; }
    public bool Retrieved { get; set; }
    public string Body { get; set; }
}
public class SecurePop3Client : TcpClient, IDisposable
{
    SslStream netStream;
    static ILog log = LogManager.GetLogger(typeof(SecurePop3Client));

    private SecurePop3Client()
    { }

    private void EstablishConnection(string serverAddress, int port, string sertificateName, string username, string password)
    {

        try
        {
            Connect(serverAddress, port);

            netStream = new SslStream(GetStream());

            netStream.AuthenticateAsClient(sertificateName);

            CheckResponse(GetServerResponse());
            CheckResponse(SendToServer(string.Format("USER {0}\r\n", username)));
            CheckResponse(SendToServer(string.Format("PASS {0}\r\n", password)));
            log.DebugFormat("Connected to {0}:{1}, with serificate :{2}", serverAddress, port, sertificateName);
        }
        catch (Exception e)
        {
            throw new SecurePop3Exception("Connecting to Email server failed", e);
        }
    }

    public void Disconnect()
    {
        CheckResponse(SendToServer("QUIT\r\n"));
        log.Debug("Disconnected from server");
    }


    public List<Pop3EMail> List()
    {
        string response;
        var ret = new List<Pop3EMail>();
        CheckResponse(SendToServer("LIST\r\n"));
        while (true)
        {
            response = GetServerResponse();
            if (response == ".\r\n")
            {
                log.DebugFormat("Retrieved {0} messages from the server", ret.Count);
                return ret;
            }
            else
            {
                try
                {
                    string[] values = response.Split(new char[] { ' ' });
                    Pop3EMail mail = new Pop3EMail
                    {
                        Number = Int32.Parse(values[0]),
                        Bytes = Int32.Parse(values[1]),
                        Retrieved = false
                    };
                    ret.Add(mail);
                }
                // catch (ArgumentNullException)
                // catch (FormatException)
                // catch (OverflowException)
                // catch (IndexOutOfRangeException)
                catch (Exception e)
                {
                    throw new SecurePop3Exception("Parsing message list failed", e);
                }
            }
        }
    }

    public void RetrieveBody(Pop3EMail mail)
    {
        string response;

        CheckResponse(SendToServer(string.Format("RETR {0}\r\n", mail.Number)));

        StringBuilder body = new StringBuilder();
        while (true)
        {
            response = GetServerResponse();
            if (response == ".\r\n")
            {
                break;
            }
            else
            {
                body.Append(response);
            }
        }
        mail.Retrieved = true;
        mail.Body = body.ToString();
        log.DebugFormat("Retrieved body of mail {0}", mail.Number);
    }


    public void Delete(Pop3EMail mail)
    {
        CheckResponse(SendToServer(string.Format("DELE {0}\r\n", mail.Number)));
        log.DebugFormat("Deleted Email {0}", mail.Number);
    }

    private string GetServerResponse()
    {
        byte[] buffer = new Byte[1024];
        int count = 0;
        while (true)
        {
            byte[] buff = new Byte[2];
            int bytes = netStream.Read(buff, 0, 1);
            if (bytes == 1)
            {
                buffer[count] = buff[0];
                count++;

                if (buff[0] == '\n')
                {
                    break;
                }
            }
            else
            {
                break;
            };
        };

        string retval = Encoding.ASCII.GetString(buffer, 0, count);
        log.DebugFormat("GOT FROM SERVER: {0}",retval);
        return retval;
    }


    private string SendToServer(string message)
    {
        try
        {
            byte[] buffer = new byte[1024];
            buffer = Encoding.ASCII.GetBytes(message);

            netStream.Write(buffer, 0, buffer.Length);
            log.DebugFormat("SEND TO SERVER: {0}", message);
            return GetServerResponse();
        }
        catch (Exception e)
        {
           throw new SecurePop3Exception(string.Format("Communication with server failed"), e);
        }
    }

    private void CheckResponse(string response)
    {
        if (string.IsNullOrEmpty(response) || response.Length < 3 || string.Compare(response.Substring(0, 3),"+OK",true) != 0)
        {
            throw new SecurePop3Exception(response);
        }
    }




    /// <summary>
    /// Factory
    /// </summary>
    /// <param name="serverAddress"></param>
    /// <param name="port"></param>
    /// <param name="sertificateName"></param>
    /// <returns></returns>
    public static SecurePop3Client Connect(string serverAddress, int port, string sertificateName, string username, string password)
    {
        SecurePop3Client client = new SecurePop3Client();
        client.EstablishConnection(serverAddress, port, sertificateName, username, password);
        return client;
    }



    #region Dispose Design Pattern Implementation
    /// <summary>
    /// Dispose
    /// </summary>
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    /// <summary>
    /// Disposes the instance.
    /// </summary>
    /// <param name="disposing">if set to <c>true</c> [disposing].</param>
    protected override void Dispose(bool disposing)
    {
        if (disposing)
        {
            Disconnect();
            netStream.Dispose();
        }
        base.Dispose(disposing);
    }

    // Use C# destructor syntax for finalization code.
    ~SecurePop3Client()
    {
        // Simply call Dispose(false).
        Dispose(false);
    }
    #endregion

}

Answer 2

CodeProject中有一个很棒的资源来处理这类事情。我已经将这个POP3 示例项目用于 C#。