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C#通过POP3获取邮件的代码(正文和附件)

作者：古镇飞天 | 来源：互联网 | 2022-01-22 05:21

C#POP3获取邮件的代码包括正文和附件，需要的朋友可以参考下。

使用方法:
获取第1封邮件

代码如下:

 
Zgke.Net.POP3 _Popt = new Zgke.Net.POP3("192.168.0.1", 110); 
DataTable _Mail = _Popt.GetMail("zk", "zk", 1); 

返回DataTable 数据内容为
Type为类型 Text为文字如果是附件为byte[] Name 如果是附件里存放的为文件名

代码如下:

using System; 
using System.Net.Sockets; 
using System.Net; 
using System.Security.Cryptography; 
using System.IO; 
using System.Data; 

namespace Zgke.Net 
{ 

///  
/// 获取邮件的类 
/// zgke@sina.com 
/// qq:116149 
///  
public class POP3 
{ 
private string m_Address = "127.0.0.1"; 

private int m_Port = 110; 

public POP3(string p_Address, int p_Port) 
{ 
m_Address = p_Address; 
m_Port = p_Port; 
} 

///  
/// 获取Mail列表 
///  
/// 用户名 
/// 密码 
/// Mail信息 
public DataTable GetMailTable(string p_Name,string p_PassWord) 
{ 
POP3Client _Client = new POP3Client(); 
_Client.UserName = p_Name; 
_Client.PassWord = p_PassWord; 
_Client.Client = new TcpClient(); 
_Client.Client.BeginConnect(m_Address, m_Port, new AsyncCallback(OnConnectRequest), _Client); 
while (!_Client.ReturnEnd) 
{ 
System.Windows.Forms.Application.DoEvents(); 
} 
if (_Client.Error.Length != 0) throw new Exception("错误信息!" + _Client.Error); 
return _Client.MailDataTable; 
} 


///  
/// 获取邮件内容 
///  
/// 名称 
/// 密码 
/// 邮件编号 
/// 数据集 
public DataTable GetMail(string p_Name, string p_PassWord, int p_MailIndex) 
{ 
POP3Client _Client = new POP3Client(); 
_Client.UserName = p_Name; 
_Client.PassWord = p_PassWord; 
_Client.Client = new TcpClient(); 
_Client.ReadIndex = p_MailIndex; 
_Client.Client.BeginConnect(m_Address, m_Port, new AsyncCallback(OnConnectRequest), _Client); 
while (!_Client.ReturnEnd) 
{ 
System.Windows.Forms.Application.DoEvents(); 
} 
if (_Client.Error.Length != 0) throw new Exception("错误信息!" + _Client.Error); 
return _Client.MailTable; 
} 

private class POP3Client 
{ 
public TcpClient Client; 

public string UserName = ""; 

public string PassWord = ""; 

public bool ReturnEnd = false; 

public DataTable MailDataTable = new DataTable(); 

public DataTable MailTable = new DataTable(); 

public string Error = ""; 

public bool ReadEnd = false; 

public int ReadIndex = -1; 


public POP3Client() 
{ 
MailDataTable.Columns.Add("NUM"); 
MailDataTable.Columns.Add("Size"); 
MailDataTable.Columns.Add("Form"); 
MailDataTable.Columns.Add("To"); 
MailDataTable.Columns.Add("Subject"); 
MailDataTable.Columns.Add("Date"); 

MailTable.Columns.Add("Type",typeof(string)); 
MailTable.Columns.Add("Text",typeof(object)); 
MailTable.Columns.Add("Name", typeof(string)); 
} 

private int m_SendMessage = 0; 
private int m_TOPIndex = 1; 

///  
/// 获取下一个登陆到获取列表需要的命令 
///  
///  
///  
public byte[] GetSendBytes(byte[] p_Value) 
{ 
ReadEnd = false; 
string _Value = System.Text.Encoding.Default.GetString(p_Value).Replace("\0", ""); 
if (_Value.IndexOf("+OK") == 0) 
{ 
m_SendMessage++; 
switch (m_SendMessage) 
{ 
case 1: 
return System.Text.Encoding.ASCII.GetBytes("USER " + UserName + "\r\n"); 
case 2: 
return System.Text.Encoding.ASCII.GetBytes("PASS " + PassWord + "\r\n"); 
case 3: 
ReadEnd = true; 
if (ReadIndex != -1) 
{ 
m_SendMessage = 5; 
return System.Text.Encoding.ASCII.GetBytes("RETR " + ReadIndex.ToString() + "\r\n"); 
} 
else 
{ 
return System.Text.Encoding.ASCII.GetBytes("LIST\r\n"); 
} 
case 4: 
string[] _List = _Value.Split(new char[] { '\r', '\n', '.' }, StringSplitOptions.RemoveEmptyEntries); 
for (int i = 1; i != _List.Length; i++) 
{ 
string[] _MaliSize = _List[i].Split(' '); 
MailDataTable.Rows.Add(new object[] { _MaliSize[0], _MaliSize[1] }); 
} 
if (MailDataTable.Rows.Count == 0) 
{ 
ReturnEnd = true; 
return new byte[0]; 
} 
else 
{ 
ReadEnd = true; 
m_TOPIndex = 1; 
return System.Text.Encoding.ASCII.GetBytes("TOP 1\r\n"); 
} 
case 5: 
System.Text.RegularExpressions.Regex _Regex = new System.Text.RegularExpressions.Regex(@"(?<=Date: ).*?(\r\n)+"); 
System.Text.RegularExpressions.MatchCollection _Collection = _Regex.Matches(_Value); 
if (_Collection.Count != 0) MailDataTable.Rows[m_TOPIndex - 1]["Date"] = GetReadText(_Collection[0].Value); 

System.Text.RegularExpressions.Regex _RegexFrom = new System.Text.RegularExpressions.Regex(@"(?<=From: ).*?(\r\n)+"); 
System.Text.RegularExpressions.MatchCollection _CollectiOnForm= _RegexFrom.Matches(_Value); 
if (_CollectionForm.Count != 0) MailDataTable.Rows[m_TOPIndex - 1]["Form"] = GetReadText(_CollectionForm[0].Value); 


System.Text.RegularExpressions.Regex _RegexTo = new System.Text.RegularExpressions.Regex(@"(?<=To: ).*?(\r\n)+"); 
System.Text.RegularExpressions.MatchCollection _CollectiOnTo= _RegexTo.Matches(_Value); 
if (_CollectionTo.Count != 0) MailDataTable.Rows[m_TOPIndex - 1]["To"] = GetReadText(_CollectionTo[0].Value); 

System.Text.RegularExpressions.Regex _RegexSubject = new System.Text.RegularExpressions.Regex(@"(?<=Subject: ).*?(\r\n)+"); 
System.Text.RegularExpressions.MatchCollection _CollectiOnSubject= _RegexSubject.Matches(_Value); 
if (_CollectionSubject.Count != 0) MailDataTable.Rows[m_TOPIndex - 1]["Subject"] = GetReadText(_CollectionSubject[0].Value); 

m_TOPIndex++; 
m_SendMessage--; 
ReadEnd = true; 
if (m_TOPIndex > MailDataTable.Rows.Count) 
{ 
ReturnEnd = true; 
return System.Text.Encoding.ASCII.GetBytes("QUIT"); 
} 
else 
{ 
return System.Text.Encoding.ASCII.GetBytes("TOP " + m_TOPIndex.ToString() + "\r\n"); 
} 
case 6: 
GetMailText(_Value); 
ReturnEnd = true; 
return System.Text.Encoding.ASCII.GetBytes("QUIT"); 

} 
} 
Error = _Value; 
ReturnEnd = true; 
return new byte[0]; 
} 

///  
/// 转换文字里的字符集 
///  
///  
///  
public string GetReadText(string p_Text) 
{ 
System.Text.RegularExpressions.Regex _Regex = new System.Text.RegularExpressions.Regex(@"(?<=\=\?).*?(\?\=)+"); 
System.Text.RegularExpressions.MatchCollection _Collection = _Regex.Matches(p_Text); 
string _Text = p_Text; 
foreach (System.Text.RegularExpressions.Match _Match in _Collection) 
{ 
string _Value = "=?" + _Match.Value; 
if (_Value[0] == '=') 
{ 
string[] _BaseData = _Value.Split('?'); 
if (_BaseData.Length == 5) 
{ 
System.Text.Encoding _Coding = System.Text.Encoding.GetEncoding(_BaseData[1]); 
_Text = _Text.Replace(_Value, _Coding.GetString(Convert.FromBase64String(_BaseData[3]))); 
} 
} 
else 
{ 
} 
} 
return _Text; 
} 


#region 获取邮件正文 和 附件 
///  
/// 获取文字主体 
///  
///  
///  
public void GetMailText(string p_Mail) 
{ 
string _COnvertType= GetTextType(p_Mail, "\r\nContent-Type: ", ";"); 
if (_ConvertType.Length == 0) 
{ 
_COnvertType= GetTextType(p_Mail, "\r\nContent-Type: ", "\r"); 
} 
int _StarIndex = -1; 
int _EndIndex = -1; 
string _ReturnText = ""; 
string _Transfer = ""; 
string _Boundary = ""; 
string _EncodingName = GetTextType(p_Mail, "charset=\"", "\"").Replace("\"", ""); 
System.Text.Encoding _Encoding = System.Text.Encoding.Default; 
if(_EncodingName!="")_Encoding = System.Text.Encoding.GetEncoding(_EncodingName); 
switch (_ConvertType) 
{ 
case "text/html;": 
_Transfer = GetTextType(p_Mail, "\r\nContent-Transfer-Encoding: ", "\r\n").Trim(); 
_StarIndex = p_Mail.IndexOf("\r\n\r\n"); 
if (_StarIndex != -1) _ReturnText = p_Mail.Substring(_StarIndex, p_Mail.Length - _StarIndex); 
switch (_Transfer) 
{ 
case "8bit": 

break; 
case "quoted-printable": 
_ReturnText = DecodeQuotedPrintable(_ReturnText, _Encoding); 
break; 
case "base64": 
_ReturnText = DecodeBase64(_ReturnText, _Encoding); 
break; 
} 
MailTable.Rows.Add(new object[] { "text/html", _ReturnText }); 
break; 
case "text/plain;": 
_Transfer = GetTextType(p_Mail, "\r\nContent-Transfer-Encoding: ", "\r\n").Trim(); 
_StarIndex = p_Mail.IndexOf("\r\n\r\n"); 
if (_StarIndex != -1) _ReturnText = p_Mail.Substring(_StarIndex, p_Mail.Length - _StarIndex); 
switch (_Transfer) 
{ 
case "8bit": 

break; 
case "quoted-printable": 
_ReturnText = DecodeQuotedPrintable(_ReturnText, _Encoding); 
break; 
case "base64": 
_ReturnText = DecodeBase64(_ReturnText, _Encoding); 
break; 
} 
MailTable.Rows.Add(new object[] { "text/plain", _ReturnText }); 
break; 
case "multipart/alternative;": 
_Boundary = GetTextType(p_Mail, "boundary=\"", "\"").Replace("\"", ""); 
_StarIndex = p_Mail.IndexOf("--" + _Boundary + "\r\n"); 
if (_StarIndex == -1) return; 
while (true) 
{ 
_EndIndex = p_Mail.IndexOf("--" + _Boundary, _StarIndex + _Boundary.Length); 
if (_EndIndex == -1) break; 
GetMailText(p_Mail.Substring(_StarIndex, _EndIndex - _StarIndex)); 
_StarIndex = _EndIndex; 
} 
break; 
case "multipart/mixed;": 
_Boundary = GetTextType(p_Mail, "boundary=\"", "\"").Replace("\"", ""); 
_StarIndex = p_Mail.IndexOf("--" + _Boundary + "\r\n"); 
if (_StarIndex == -1) return; 
while (true) 
{ 
_EndIndex = p_Mail.IndexOf("--" + _Boundary, _StarIndex + _Boundary.Length); 
if (_EndIndex == -1) break; 
GetMailText(p_Mail.Substring(_StarIndex, _EndIndex - _StarIndex)); 
_StarIndex = _EndIndex; 
} 
break; 
default: 
if (_ConvertType.IndexOf("application/") == 0) 
{ 
_StarIndex = p_Mail.IndexOf("\r\n\r\n"); 
if (_StarIndex != -1) _ReturnText = p_Mail.Substring(_StarIndex, p_Mail.Length - _StarIndex); 
_Transfer = GetTextType(p_Mail, "\r\nContent-Transfer-Encoding: ", "\r\n").Trim(); 
string _Name = GetTextType(p_Mail, "filename=\"", "\"").Replace("\"", ""); 
_Name = GetReadText(_Name); 
byte[] _FileBytes = new byte[0]; 
switch (_Transfer) 
{ 
case "base64": 
_FileBytes = Convert.FromBase64String(_ReturnText); 
break; 
} 
MailTable.Rows.Add(new object[] { "application/octet-stream", _FileBytes, _Name }); 

} 
break; 
} 
} 

///  
/// 获取类型（正则） 
///  
/// 原始文字 
/// 前文字 
/// 结束文字 
/// 符合的记录 
public string GetTextType(string p_Mail, string p_TypeText, string p_End) 
{ 
System.Text.RegularExpressions.Regex _Regex = new System.Text.RegularExpressions.Regex(@"(?<=" + p_TypeText + ").*?(" + p_End + ")+"); 
System.Text.RegularExpressions.MatchCollection _Collection = _Regex.Matches(p_Mail); 
if (_Collection.Count == 0) return ""; 
return _Collection[0].Value; 
} 

///  
/// QuotedPrintable编码接码 
///  
/// 原始文字 
/// 编码方式 
/// 接码后信息 
public string DecodeQuotedPrintable(string p_Text, System.Text.Encoding p_Encoding) 
{ 
System.IO.MemoryStream _Stream = new System.IO.MemoryStream(); 
char[] _CharValue = p_Text.ToCharArray(); 
for (int i = 0; i != _CharValue.Length; i++) 
{ 
switch (_CharValue[i]) 
{ 
case '=': 
if (_CharValue[i + 1] == '\r' || _CharValue[i + 1] == '\n') 
{ 
i += 2; 
} 
else 
{ 
try 
{ 
_Stream.WriteByte(Convert.ToByte(_CharValue[i + 1].ToString() + _CharValue[i + 2].ToString(), 16)); 
i += 2; 
} 
catch 
{ 
_Stream.WriteByte(Convert.ToByte(_CharValue[i])); 
} 
} 
break; 
default: 
_Stream.WriteByte(Convert.ToByte(_CharValue[i])); 
break; 
} 
} 
return p_Encoding.GetString(_Stream.ToArray()); 
} 

///  
/// 解码BASE64 
///  
///  
///  
///  
public string DecodeBase64(string p_Text, System.Text.Encoding p_Encoding) 
{ 
if (p_Text.Trim().Length == 0) return ""; 
byte[] _ValueBytes = Convert.FromBase64String(p_Text); 
return p_Encoding.GetString(_ValueBytes); 
} 
#endregion 


} 

///  
/// 连接事件 
///  
///  
private void OnConnectRequest(IAsyncResult ar) 
{ 
POP3Client _Client = (POP3Client)ar.AsyncState; 
byte[] _ReadBytes =new byte[0]; 
_Client.Client.Client.BeginReceive(_ReadBytes, 0, 0, SocketFlags.None, new AsyncCallback(OnWrite), _Client); 
} 

///  
/// 连接事件 
///  
///  
private void OnSend(IAsyncResult ar) 
{ 
POP3Client _Client = (POP3Client)ar.AsyncState; 
byte[] _ReadBytes = new byte[0]; 
_Client.Client.Client.BeginReceive(_ReadBytes, 0, 0, SocketFlags.None, new AsyncCallback(OnWrite), _Client); 
} 

///  
/// 连接事件 
///  
///  
private void OnWrite(IAsyncResult ar) 
{ 
POP3Client _Client = (POP3Client)ar.AsyncState; 
byte[] _WriteBytes = new byte[_Client.Client.Client.ReceiveBufferSize]; 
_Client.Client.Client.Receive(_WriteBytes); 
if (_Client.ReadEnd) _WriteBytes = ReadEnd(_WriteBytes, _Client); 
byte[] _SendBytes = _Client.GetSendBytes(_WriteBytes); 
if (_SendBytes.Length == 0) return; 
_Client.Client.Client.BeginSend(_SendBytes, 0, _SendBytes.Length, SocketFlags.None, new AsyncCallback(OnSend), _Client); 
} 

///  
/// 获取知道获取到. 否则一直获取数据 
///  
///  
///  
private byte[] ReadEnd(byte[] p_Value,POP3Client p_Client) 
{ 
if (System.Text.Encoding.ASCII.GetString(p_Value).IndexOf("\r\n.\r\n") != -1) return p_Value; 
MemoryStream _Stream = new MemoryStream(); 
_Stream.Write(p_Value, 0, p_Value.Length); 
while (true) 
{ 
byte[] _WriteBytes = new byte[p_Client.Client.ReceiveBufferSize]; 
p_Client.Client.Client.Receive(_WriteBytes); 
_Stream.Write(_WriteBytes, 0, _WriteBytes.Length); 
System.Threading.Thread.Sleep(100); 
if (System.Text.Encoding.ASCII.GetString(_WriteBytes).IndexOf("\r\n.\r\n") != -1) return _Stream.ToArray(); 
} 
} 

} 
}