C#读取文件夹里的TXT文本，汉子部分乱码？

Question

private void ReadData()
        {
            string sql = "";
            System.IO.DirectoryInfo di = new System.IO.DirectoryInfo("G:\\TXT"); 
            FileInfo[] ff = di.GetFiles("*.txt");  //只取文本文件
            foreach (FileInfo temp in ff)
            {
                using (StreamReader sr = temp.OpenText())
                {
                    con.Open();
                    string all1 = sr.ReadToEnd(); //从开始到末尾位置全部读取
                    string tid = all1.Substring(18, 8);
                    string tname = all1.Substring(28);
                    sql = "insert into txttest(t_id,t_name) values('"+tid+"','"+tname+"')";
                    OracleCommand cmd = new OracleCommand(sql, con);
                    cmd.ExecuteNonQuery();
                    con.Close();
                }
                temp.Delete(); //删除文件
            }        }
  

Answer 1

string sql = "";
System.IO.DirectoryInfo di = new System.IO.DirectoryInfo("G:\\TXT");
FileInfo[] ff = di.GetFiles("*.txt");  //只取文本文件
foreach (FileInfo temp in ff)
{
using (StreamReader sr = new StreamReader(temp.FullName, Encoding.GetEncoding("gb2312")))
{
con.Open();
string all1 = sr.ReadToEnd(); //从开始到末尾位置全部读取
string tid = all1.Substring(18, 8);
string tname = all1.Substring(28);
sql = "insert into txttest(t_id,t_name) values('" + tid + "','" + tname + "')";
OracleCommand cmd = new OracleCommand(sql, con);
cmd.ExecuteNonQuery();
con.Close();
}
temp.Delete(); //删除文件
}