这两天在做POP3邮件收取，收件人信息总是乱码，仔细研究了一下，找到规则如下=?编码规则?编码方式?内容?=
编码方式分两种B代表Base64，Q代表QP
下面是C#解决办法。
另外在开源的LumiSoft.Net.Core.CanonicalDecode 这个类中也能找到解决方法，编译的时候提示 "LumiSoft.Net.Core.CanonicalDecode(string)"已过时:"Use MimeUtils.DecodeWords method instead."其实这个替换类并不好用，有的内容解析不出来，还是老方法管用
测试数据
=?GB2312?B?ufq6vdaq0vQ=?= 国航知音
=?GBK?B?1tDQxdDF08O/qNbQ0MQ=?= 中信信用卡中心
=?gb2312?q?SMS=CA=FD=BE=DD=B1=ED=CB=B5=C3=F7?= SMS数据表说明
| #region 邮件标题编码 private string DecodeMailSubject(string subject) {//格式为 =?编码规则?编码方式?内容?= try { string[] str = subject.Split('?'); string ruler = str[1]; string codetype = str[2]; string code = str[3]; if (codetype.ToLower() == "q") return DecodeQP(ruler, code); if (codetype.ToLower() == "b") return DecodeBase64(ruler, code); return code; } catch { return subject; } } private string DecodeBase64(string code_type, string code) { string decode = ""; byte[] bytes = Convert.FromBase64String(code); try { decode = Encoding.GetEncoding(code_type).GetString(bytes); } catch { decode = code; } return decode; } private string DecodeQP(string code_type, string code) { string decode = ""; try { char ch, ch1, ch2; int chint, chint1, chint2; if (code != null) { code = code.Replace("=09", ""); code = code.Replace("==", "="); } char[] hz = code.ToCharArray();
byte[] bytes = new byte[2]; decode = ""; for (int i = 0; i < code.Length; i++) { ch = hz[i]; if (ch == '=') { i++; ch1 = hz[i]; if (ch1 == 13 || ch1 == 10) { //i++; continue; } i++; ch2 = hz[i]; if (ch1 == '3' && ch2 == 'D') { //System.Text.Encoding.GetEncoding(54936).GetString(b); decode += "="; continue; } else {
if (ch1 > '9') { chint1 = (ch1 - 'A' + 10) * 16; } else { chint1 = (ch1 - '0') * 16; } if (ch2 > '9') { chint2 = ch2 - 'A' + 10; } else { chint2 = ch2 - '0'; }
ch = hz[i + 1]; if (ch != '=') { decode += ch1.ToString(); decode += ch2.ToString(); continue; } chint = chint1 + chint2; bytes[0] = Convert.ToByte(chint);
i = i + 2; ch1 = hz[i]; while (ch1 == 13 || ch1 == 10) { i++; i++; ch1 = hz[i]; } if (ch1 == '=') { i++; ch1 = hz[i]; } i++; ch2 = hz[i];
if (ch1 > '9') { chint1 = (ch1 - 'A' + 10) * 16; } else { chint1 = (ch1 - '0') * 16; } if (ch2 > '9') { chint2 = ch2 - 'A' + 10; } else { chint2 = ch2 - '0'; }
chint = chint1 + chint2; bytes[1] = Convert.ToByte(chint);
decode += System.Text.Encoding.GetEncoding(code_type).GetString(bytes);
}
} else { decode += ch.ToString(); } } } catch { decode = code; } return decode;
}
#endregion |