c#怎么读取mysql中 mediumtext类型的数据

如题：
C# code:
MySQLConnection con = new MySQLConnection( new MySQLConnectionString("localhost","beephpcms","root","root").AsString);
try
{
DataSet ds = new DataSet();
con.Open();
MySQLCommand cmd = new MySQLCommand("set names 'gb2312'", con);
cmd.ExecuteNonQuery();
MySQLCommand com = new MySQLCommand("select contentid as id,content from phpcms_c_news where content like '%news_%html%'", con);
MySQLDataReader mydr = com.ExecuteReaderEx();
while (mydr.Read())
{
string content = "";
string id = "";
id = mydr["id"].ToString();
content=mydr["content"].ToString();//此行报错，content是mediumtext类型数据
}
mydr.Close();
con.Close();

}
catch (Exception error)
{
MessageBox.Show(error.Message);
}




请指点如何读取mediumtext类型数据

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string content = "";

mediumtext 其实本质上是BLOB， 所以用 byte[]

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能再详细些吗？

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stri