以前碰到的一些问题记录

1、在JS中如何取得这个列表的选择项（不是Value属性）

答案
<select name="JobName" id="JobName" onChange="alert(this.options[this.selectedIndex].text)">
    <option value="28838">销售工程师</option>
    <option value="23343">项目总监</option>
    <option value="12434">商务代表</option>
    <option value="28734">销售主任</option>
    <option value="28779">高级外贸跟单文員</option>
</select>
2、泛型方法定义
 
 答案

        public T GetValue<T>(string sql)
        {
            SqlConnection conn = new SqlConnection(connstring);
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            cmd.CommandText = sql;
            conn.Open();
            try
            {
                return (T)cmd.ExecuteScalar();
            }
            catch
            {
                return default(T);
            }
            finally
            {
                cmd.Dispose();
                conn.Close();
            }
        }

        public static List<Model.UserInfo> GetOnLineUsers(string strSql)
        {
            List<Model.UserInfo> list = new List<Model.UserInfo>();
            SqlConnection con = new SqlConnection(strCon);
            try
            {
                con.Open();
                SqlCommand com = new SqlCommand(strSql, con);
                com.CommandType = CommandType.StoredProcedure;
                SqlDataReader dr = com.ExecuteReader();
                while (dr.Read())
                {
                    Model.UserInfo model = new Model.UserInfo();
                    model.UserName = dr["userName"].ToString();
                    model.Id = (int)dr["id"];
                    list.Add(model);
                }
                return list;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
            finally
            {
                con.Close();
            }
        }

3、Access插入、更新数据库的问题
4、

错误 15 类型“AdminPage”同时存在于“c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\9c74ad28\626c96e4\assembly\dl3\bcb35a71\00707404_b43cca01\App_Code.DLL”和“c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\9c74ad28\626c96e4\App_Code.bb9dbmvv.dll”中 E:\andy\CompanySite\Liping.Web\admin\News\NewsAdd.aspx.cs 13 43 http://localhost:8888/

错误 64 类型“AdminPage”同时存在于“c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\9c74ad28\626c96e4\assembly\dl3\bcb35a71\00707404_b43cca01\App_Code.DLL”和“c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\9c74ad28\626c96e4\App_Code.yfc5m9z2.dll”中 E:\andy\CompanySite\Liping.Web\admin\News\NewsAdd.aspx.cs 13 

以上原因是因为AdminPage是一个基类，多个页面都继承了该基类，而该基类是建站App_Code文件夹下。
解决方法是：把App_Code里的AdminPage基类分离出来单独建一个项目，然后每个页面引类该项目里的AdminPage基类