提示应输入标识符是什么意思

， namespace Sum_ShopYSFee { using bc; using Excel; using System; using System.Configuration; using System.Data; using System.Data.SqlClient; using System.IO; using System.Reflection; using System.Runtime.InteropServices; using System.Text; using System.Text.RegularExpressions; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; public class Sum_ComYFee : BaseClass { // Methods public Sum_ComYFee() { } private void a(object， ImageClickEventArgs) { string text1; ApplicationClass class1 null; Workbook workbook1 null; Worksheet worksheet1 null; if (this.Session[app] null) { if (base.Application[app] null) { class1 new ApplicationClass(); base.Application[app] class1; class1.Visible false; goto Label_0089; } class1 (ApplicationClass) base.Application[app]; this.Session[app] class1; } else { class1 (ApplicationClass) this.Session[app]; } ，，， // Fields protected ImageButton bt_Chart; protected ImageButton cmdPrint; protected DataGrid DataGrid1; protected DataGrid Datagrid2; protected DropDownList ddlArea; protected TextBox endtime; protected ImageButton export; protected ImageButton ImageButton1; protected ImageButton ImageButton2; protected ImageButton ImageButton3; protected ImageButton ImageButton4; protected ImageButton ImageButton5; protected Label Label19; protected Label PageInfo; protected TextBox startime; protected Label sumdate; protected Label SumItemName; protected DropDownList yearlist; protected Label yf; } } 以上这段程序有多次地方提示应输入标识符是什么原因请各位高手帮帮忙了 。

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