D6JIEFENGMAIL/mailtools/ReceivemailTool.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MailAnalyzeTools.Common;
using OpenPop.Pop3;
using System.Windows.Forms;
using MailAnalyzeTools.Models;

namespace MailAnalyzeTools
{
    class ReceiveMailTool
    {
        /// <summary>
        /// 连接邮件服务器
        /// </summary>
        /// <param name="pop3Client"></param>
        /// <param name="txtMailServer"></param>
        /// <param name="iPort"></param>
        /// <param name="chkSSL"></param>
        /// <param name="txtUserName"></param>
        /// <param name="txtPassword"></param>
        /// <param name="showErrTip"></param>
        /// <returns></returns>
        private static bool ConnectMailServer(Pop3Client pop3Client, string txtMailServer, int iPort, bool chkSSL, string txtUserName, string txtPassword, bool showErrTip = false)
        {
            try
            {
                pop3Client.Connect(txtMailServer, iPort, chkSSL);
                pop3Client.Authenticate(txtUserName, txtPassword);
            }
            catch (Exception ex)
            {
                LogHelper.WriteLog(typeof(ReceiveMailTool), ex);
                //MessageBox.Show(String.Format(info, ex.Message));
                return false;
            }
            return true;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="lblInfo"></param>
        public static void DeleteOver3daysMail(Label lblInfo, bool showPrompt = true, int para_ioverdays = 3)
        { 
            bool conOk;
            Pop3Client pop3Client = new Pop3Client();
            conOk = frmAnalyzeMail.GetOpenClient(pop3Client);
            if (!conOk)
            {
                // MessageBox.Show("无法连接到服务器");
                return;
            } 
            //至少保留2天的数据
            int ioverdays= para_ioverdays<=2?2:para_ioverdays;
            int iend = BinarySearchOver3days(pop3Client, ioverdays);
            if (iend > 0)
            {    //查询到位置)
                OpenPop.Mime.Header.MessageHeader mlhd = pop3Client.GetMessageHeaders(iend);
                if(showPrompt)
                {
                    string info = string.Format("将要删除3天以上的历史邮件{0}封,要删除的最近的一封邮件信息是:{1}\n您确信要删除这些邮件吗?",
                  iend, (string.IsNullOrEmpty(mlhd.Subject) ? "[无标题]" : mlhd.Subject) + mlhd.DateSent.ToLocalTime().ToString());
                    if (MessageBox.Show(null, info, "信息提醒", MessageBoxButtons.YesNo, MessageBoxIcon.Question) != DialogResult.Yes)
                    {
                        return;
                    }
                 }
                if (lblInfo != null)
                    lblInfo.Visible = true;
                List<string> uidsTodelList = new List<string>();
                //倒序删除
                string lstinfo = "正在删除第{0}/{1}封邮件关键字息...";
                int ipos = iend;
                for (; ipos >= 1; ipos--)
                {
                    Application.DoEvents();
                    if (lblInfo != null)
                        lblInfo.Text = string.Format(lstinfo, iend - ipos, iend);
                    pop3Client.DeleteMessage(ipos);
                }
                System.Threading.Thread.Sleep(500);
              
                pop3Client.Disconnect();
            }
        }
        /// <summary>  
        /// 二分法查找  
        /// </summary>  
        /// <param name="arr"></param>  
        /// <param name="key">要查找的对象</param>  
        public static int BinarySearchOver3days(Pop3Client pop3Client, int overdays = 3)
        {
            int low = 1;
            int high = pop3Client.GetMessageCount();
            if (high < 1)
                return 0;
            DateTime dtsent = pop3Client.GetMessageHeaders(1).DateSent.ToLocalTime();
            if (StrUtill.DateDiff(DateTime.Today, dtsent.Date) < overdays)//第一封信不超过3天则退出
                return 0;
            int imid = (low + high) / 2;
            while (imid < high && imid >= low)
            {
                int middle = (low + high) / 2;
                dtsent = pop3Client.GetMessageHeaders(middle).DateSent.ToLocalTime();
                int days = StrUtill.DateDiff(DateTime.Today, dtsent.Date);

                if (days < overdays)//3天以内  
                {
                    imid = middle - 1;
                    dtsent = pop3Client.GetMessageHeaders(imid).DateSent.ToLocalTime();
                    days = StrUtill.DateDiff(DateTime.Today, dtsent.Date);
                    if (days >= overdays) //符合3天以外
                    {
                        return imid;//如果找到了就直接返回这个元素的索引  

                    }
                    high = middle - 1;
                    imid = (low + high) / 2;
                }
                else  //超过3天
                {
                    imid = middle + 1;
                    dtsent = pop3Client.GetMessageHeaders(imid).DateSent.ToLocalTime();
                    days = StrUtill.DateDiff(DateTime.Today, dtsent.Date);
                    if (days < overdays) //符合3天内
                    {
                        return middle; //如果找到了就直接返回这个元素的索引  

                    }
                    else
                        low = imid;//超过3天 
                }
            }
            return -1;//如果找不到就返回-1；  
        }


    }
}