转自：http://www.yongfa365.com/Item/HuiZongRuHeYouXiaoDeShiYongCDuQuWenJianJiRuHeJieJueZhongWenLuanMaWenTi.html
用c#读取文件内容中文是乱码的解决方法：
//方法1：
StreamReader din = new StreamReader(@"C:\1.txt", System.Text.Encoding.GetEncoding("gb2312"));
string html = "";
while (din.Peek() > -1)
{
html = html + din.ReadToEnd();
}
din.Close();
//方法2：
StreamReader sr1 = new StreamReader((System.IO.Stream)File.OpenRead(filename), System.Text.Encoding.Default);
html = "";
while (sr1.Peek() > -1)
{
html = html + sr1.ReadLine();
}
sr1.Close();
//方法3：
StreamReader objReader = new StreamReader(@"C:\1.txt", System.Text.Encoding.GetEncoding("gb2312"));
string sLine = "", html = "";
while (sLine != null)
{
sLine = objReader.ReadLine();
if (sLine != null)
html += sLine;
}
objReader.Close();