ContentText.contents 不可访问，因为它受保护级别限制

public class Operator
{
public Operator()
{
//
//TODO: 在此处添加构造函数逻辑
//
}



public static SqlConnection ConnecionDB()
{
SqlConnection con = new SqlConnection("server=.;DataBase=ContentDB;Trusted_Connection=true;");
return con;
}

public static bool AddContent(ContentText ct)
{
try {
SqlConnection con = Operator.ConnecionDB();
con.Open();
string str = "insert into ContentText(userName,tel,email,contents)values(@userName,@tel,@email,@contents)";
SqlCommand cmd = new SqlCommand(str,con);
SqlParameter param = new SqlParameter("@userName",SqlDbType.Char,10);
param.Value=ct.userName;
cmd.Parameters.Add(param);
param = new SqlParameter("@email",SqlDbType.Char,20);
param.Value=ct.email;
cmd.Parameters.Add(param);
param = new SqlParameter("@tel",SqlDbType.Char,20);
param.Value = ct.tel;
cmd.Parameters.Add(param);
param = new SqlParameter("@contents",SqlDbType.NVarChar);
param.Value = ct.contents;
cmd.Parameters.Add(param);
cmd.ExecuteNonQuery();
return true;
}
catch
{
return false;
}
}
}


都是public 怎么也不行 啊 求指导