由于初学比较生疏所以由衷的请求各位帮帮。。。。。万分感谢

我是要把子节点输出在文本框里

            db.foodname=treeView1.SelectedNode.Text;
            textBox2.Text = db.foodname;
            textBox2.ReadOnly = true;
            if (treeView1.SelectedNode.Level > 1)
            {
                SqlConnection con = db.qq();
                con.Open();
                string sql="select id,foodprice from tb_food where foodname='"+db.foodname+"'";
                SqlCommand com = new SqlCommand(sql, con);
                SqlDataReader dr = com.ExecuteReader();
                if (dr.Read())
                {
                    textBox1.Text = dr["id"].ToString();
                    textBox3.Text = dr["foodprice"].ToString();
                }
            }

我就是这么写的就是不对

关键是他不报错啊  db是个函数集   我把打开数据库放在db里面

就是不显示出来

那个可以显示我直接那样就可以显示