c# 收取邮件 解析_C# 解析eml邮件内容
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Text.RegularExpressions;
using System.IO;
namespace MailResolve
{
public partial class FormSesolve : Form
{
StreamReader sr;
string MailFlag;
public FormSesolve()
{
InitializeComponent();
}
private void buttonResolve_Click(object sender, EventArgs e)
{
textBoxSubject.Text = "";
textBoxTo.Text = "";
textBoxFrom.Text = "";
textBoxCc.Text = "";
richTextBoxContent.Text = "";
richTextBoxAtt.Text = "";
//创建字符串输入流
sr = new StreamReader(GenerateStreamFromString(richTextBoxMail.Text));
string str;
int i;
while (sr.EndOfStream == false)
{
str = sr.ReadLine();
if ((i = str.IndexOf("Subject:")) == 0)
{
//修改标题
textBoxSubject.Text = Conv(str.Substring(8));
continue;
}
if ((i = str.IndexOf("From:")) == 0)
{
//修改发件人，存在一个如果发件人为多行会导致显示不全，没有进行相应的处理
textBoxFrom.Text = Conv(str.Substring(5));
continue;
}
if ((i = str.IndexOf("To:")) == 0)
{
//此处收件人地址和发件人存在相同问题
textBoxTo.Text = Conv(str.Substring(3));
continue;
}
if ((i = str.IndexOf("Cc:")) == 0)
{
//提取抄送地址，问题一样
textBoxCc.Text = Conv(str.Substring(3));
continue;
}
if ((i = str.IndexOf("Bcc:")) == 0)
{
//密抄地址，问题一样
textBoxBcc.Text = Conv(str.Substring(4));
continue;
}
if ((i = str.IndexOf("Content-Type:")) == 0)
{
//如果存在类型标示
string[] type = GetContentType(str);
//获取类型标示，type[0]标示类型如text、application、multipart
//type[1] 仅对text有效、标示具体类型
//type[2] 相应的编码(utf-8等)或者附件名称(有name、filename两种写法导致type[1]不准确)
//Console.WriteLine(type[0]+" "+type[1]+" "+type[2]);
if (type[0] == "text")
{
string s = "";
switch (GetEncoding())
{
//获取对应的文本处理方式 返回小写字符
case "base64":
s = Encoding.GetEncoding(type[2].ToUpper()).GetString(Convert.FromBase64String(GetContent()));
break;
case "quoted-printable":
s = QPUnEncryCode(GetContent(), type[2]);
break;
default:
s = GetContent().Trim();//啥都没有直接删除前后的空白
break;
}
if (type[1] == "html")
{
//类型为html输出到浏览器控件
webBrowser.DocumentText = s;
}
else
{
//纯文本输出到存文本控件
richTextBoxContent.Text = s;
}
}
else if (type[0] == "multipart")
{
//邮件唯一标示符
//删除 ‘-’在于部分邮件 '-'前后数量不一致，简单删除了全部
MailFlag = type[2].Replace("-", "");
}
else if (type[0] == "application")
{
//附件的处理
//此处仅仅对名字进行添加
richTextBoxAtt.Text += Conv(type[2]) + "\t";
SaveFile(Conv(type[2]), GetContent());
}
continue;
}
}
}
private string GetContent()
{
//获取Conten-Type:获取之后的相应内容
string str;
string rt = "";
while ((str = sr.ReadLine()) != "") ; //内容会从空行之后开始，读取到空行内容
while (true)
{ //开始循环读取内容
str = sr.ReadLine();
if (str == null) //读取为空
break;
if (MailFlag != null)
{ //存在邮件标示的情况，如果不存在会一直读取到邮件结束，PHPMailer就有这样一个问题
if (str.Replace("-", "").IndexOf(MailFlag) >= 0) //读取到邮件标示符结束
{
break;
}
}
rt += str + "\n";
}
return rt;
}
private string GetEncoding()
{
//获取下一行的邮件内容编码，如果不在下一行忽略
string s = sr.ReadLine();
if (s.ToLower().IndexOf("content-transfer-encoding:") != 0)
{
return "";
}
return s.Split(' ')[1].ToLower().Trim();
}
private string[] GetContentType(string str)
{
//获取Content-Type属性
//Content-Type: text/plain; charset="gb2312"
//该类型将会返回string[] = {"text","plain","gb2312"}
string[] s, rt, s3;
rt = new string[3];
if (str.ToLower().IndexOf("charset") < 1 &&
str.ToLower().IndexOf("name") < 1 &&
str.ToLower().IndexOf("boundary") < 1)
{
//这里只对这三种情况惊喜下一行考虑，其他情况忽略
str += sr.ReadLine();
}
str = str.Replace(""", "");
s = str.Split(';');
s[0] = s[0].Trim();
s[1] = s[1].Trim();
s3 = s[0].Substring(s[0].IndexOf(" ") + 1).Trim().Split('/');
rt[0] = s3[0];
rt[1] = s3[1];
rt[2] = s[1].Substring(s[1].IndexOf("=") + 1).Trim();
return rt;
}
private Stream GenerateStreamFromString(string s)
{
//根据字符串创建一个文件流
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.Write(s);
writer.Flush();
stream.Position = 0;
return stream;
}
private string Conv(string s)
{
//转换 标题中的 字符
//=?gb2312?B?u9i4tDogu9i4tKO6udjT2tT2vNNXb3JkcHJlc3Ox7cfpvLDQ3rjExL/CvA==?=
s = s.Trim();
Regex reg = new Regex(@"=\?(?[\s\S]+)\?=");
MatchCollection matches;
matches = reg.Matches(s);
for (int i = 0; i < matches.Count; i++)
{
s = s.Replace(matches[i].Value, GetConvString(matches[i].Value));
}
return s;
}
private string GetConvString(string s)
{
//转换相应的编码内容
string[] s2 = s.Split('?');
if (s2[2].ToLower() == "b")
{
//Base64转换
s = Encoding.GetEncoding(s2[1].ToUpper()).GetString(Convert.FromBase64String(s2[3]));
}
else
{
//quoted-printable 编码转换
s = QPUnEncryCode(s2[3], s2[1]);
}
return s;
}
private string QPUnEncryCode(string source, string coding)
{
//quoted-printable 转换为相应的字符串
//此处为网上的代码，有点小问题，未做深入探索
source = source.Replace("=\r\n", "");
source = source.Replace("=\n", "");
int len = source.Length;
string dest = string.Empty;
int i = 0;
while (i < len)
{
string temp = source.Substring(i, 1);
if (temp == "=")
{
try //代码会出去解析异常，对这样问题进行屏蔽，但会导致乱码
{
int code = Convert.ToInt32(source.Substring(i + 1, 2), 16);
if (Convert.ToInt32(code.ToString(), 10) < 127)
{
dest += ((char)code).ToString();
i = i + 3;
}
else
{
try //这是另一处转换异常
{
dest += Encoding.GetEncoding(coding.ToUpper()).GetString(new byte[] {
Convert.ToByte(source.Substring(i + 1, 2), 16),
Convert.ToByte(source.Substring(i + 4, 2), 16)
});
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
i = i + 6;
}
}
catch
{
i++;
continue;
}
}
else
{
dest += temp;
i++;
}
}
return dest;
}
private void SaveFile(string file, string content)
{
//将附件写入到文件
FileStream fs = new FileStream(file, FileMode.Create);
byte[] bs = Convert.FromBase64String(content);
fs.Write(bs, 0, bs.Length);
fs.Close();
}
private void FormSesolve_Resize(object sender, EventArgs e)
{
//窗口调整
}
}
}