读取文档时避免文档中因汉字儿出现乱码

 StreamReader sd = new StreamReader(path, Encoding.GetEncoding("gb2312"));
 string sd = File.ReadAllText(path,Encoding.GetEncoding("gb2312"));
 StreamReader sd = File.ReadAllText(path, GetEncoding("gb2312"));

读取文档时避免文档中因汉字儿出现乱码