添加文章，需要用到一个类DataSet，怎样添加引用？
要使用类SqlData下面的方法GetDataSet()
新建了个文件夹App_code，下面放有SqlData.cs
编译的时候提示错误:未能找到类型或命名空间名称“SqlData”(是否缺少 using 指令或程序集引用?)
怎样引用这个类呢？
引用下面没办法添加啊。
Add_News.aspx.cs
using System;using System.Data;using System.Configuration;using System.Collections;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.Data.SqlClient;namespace blog.Backstage.Users{ public partial class Add : System.Web.UI.Page { SqlData mydata = new SqlData(); int cbox; string ID; protected void Page_Load(object sender, EventArgs e) { if (Session["UserName"] == null) { Response.Redirect("~/index.aspx"); } string sql = "select * from tb_Blog where UserName='" + Session["UserName"] + "'"; DataSet mydataset = mydata.GetDataSet(sql, "tb_Blog"); DataRowView rowview = mydataset.Tables["tb_Blog"].DefaultView[0]; ID = rowview["BlogID"].ToString(); this.TextBox2.Text = Session["UserName"].ToString(); string sqlstr = "select * from ST_Class"; SqlConnection mycon = new SqlConnection(ConfigurationManager.AppSettings["conStr"]); SqlCommand mycom = new SqlCommand(sqlstr, mycon); mycon.Open(); SqlDataReader dr = mycom.ExecuteReader(); //判断是否有数据 while (dr.Read()) { DropDownList1.Items.Add(new ListItem(dr["ST_c_name"].ToString(), dr["ST_c_id"].ToString())); } mycon.Close(); } protected void btnAdd_Click(object sender, EventArgs e) { string ID; string sqlstr = "select * from tb_Blog where UserName='" + Session["UserName"] + "'"; DataSet mydataset = mydata.GetDataSet(sqlstr, "tb_Blog"); DataRowView rowview = mydataset.Tables["tb_Blog"].DefaultView[0]; ID = rowview["BlogID"].ToString(); //创建插入新文章信息的Sql语句 string com = "Insert into ST_news(ST_n_title,ST_n_author,ST_n_key,ST_n_content,ST_n_iscmd,ST_c_id,BlogID) values('" + this.txtSubject.Text + "','" + this.Session["UserName"].ToString() + "','" + this.TextBox1.Text + "','" + this.article_context.Text.ToString() + "','" + cbox + "','" + this.DropDownList1.SelectedValue + "','" + ID + "')"; //调用公共类中的ExceSQL方法，返回一个布尔值 bool add = mydata.ExceSQL(com); if (add) { Response.Write("<script language=javascript>alert('文章添加成功!');location='ArticleManage.aspx'</script>"); } else { Response.Write("<script language=javascript>alert('文章添加失败！');location='javascript:history.go(-1)'</script>"); } } }}