c#中 ExecuteReader: CommandText 属性尚未初始化 问题

using System;
using System.Data;
using System.Configuration;
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.Text.RegularExpressions;
using System.Data.SqlClient;
using System.Collections;
using System.IO;/// <summary>
/// DBFun 的摘要说明
/// </summary>
public class DBFun
{
    protected static SqlConnection conn = new SqlConnection();
    protected static SqlCommand comm = new SqlCommand();  
    public static void IsAdmin()
    {
        //查看是否为超级管理员
        if (HttpContext.Current.Session["usr_id"] != null)
        {
            string strsql = string.Format("select usr_name from usrinfo where rank_id =5 and usr_id='{0}'", HttpContext.Current.Session["usr_id"].ToString());
            DataSet ds = dataSet(strsql);
            string xm;            if (ds != null & ds.Tables.Count > 0 & ds.Tables[0].Rows.Count > 0)
            {
                xm = ds.Tables[0].Rows[0]["usr_name"].ToString();
            }
            else
            {
                HttpContext.Current.Response.Write("<script>alert('你还没有登录或登录超时！');window.location.href='login.aspx';</script>");
            }
        }
        else
        {
            HttpContext.Current.Response.Write("<script>alert('你还没有登录或登录超时！');window.location.href='login.aspx';</script>");
        }     } public DBFun()
{
//
// TODO: 在此处添加构造函数逻辑
//
}    /// 打开数据库连接 
    private static void openConnection()
    {
        if (conn.State == ConnectionState.Closed)
        {
            conn.ConnectionString = "Data Source=.;Initial Catalog=OfficeOnLine;User ID=sa;Password=sa";
            comm.Connection = conn;
            try
            {
                conn.Open();
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }
    }    /// 关闭当前数据库连接 
    private static void closeConnection()
    {
        if (conn.State == ConnectionState.Open)
            conn.Close();
        comm.Dispose();
        conn.Dispose();    }
    /// 执行Sql查询语句 
    /// <param name="sqlstr">传入的Sql语句</param> 
    public static void ExecuteSql(string sqlstr)
    {
        try
        {
            openConnection();
            comm.CommandType = CommandType.Text;
            comm.CommandText = sqlstr;
            comm.ExecuteNonQuery();
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
        finally
        {
            closeConnection();
        }
    }    /// <summary> 
    /// 执行Sql更新语句 
    /// </summary> 
    /// <param name="sqlstr">传入的Sql语句</param>
    /// <returns>布尔值</returns>
    public static bool ExecuteUpdate(string sqlstr)
    {
        int isUpdateOk = 0;
        try
        {
            openConnection();
            comm.CommandType = CommandType.Text;
            comm.CommandText = sqlstr;
            isUpdateOk = Convert.ToInt32(comm.ExecuteNonQuery());
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
        finally
        {
            closeConnection();
        }
        if (isUpdateOk > 0)
        {
            return true;
        }
        else
        {
            return false;
        }
    }    public static DataRow GetDataRow(string strSQL)
    {
        //查询数据，取得数据行
        try
        {
            openConnection();
            SqlDataAdapter sda = new SqlDataAdapter(strSQL, conn);
            DataSet Rs = new DataSet();
            sda.Fill(Rs);
            if (Rs.Tables[0].Rows.Count != 0)
                return Rs.Tables[0].Rows[0];
            else
                return null;
        }
        catch
        {
            return null;
        }    }
    public static DataView GetDataView(string strSQL)
    {
        //查询数据，取得数据视图
        try
        {
            openConnection();
            SqlDataAdapter sda = new SqlDataAdapter(strSQL, conn);
            DataSet Rs = new DataSet();
            sda.Fill(Rs);
            return Rs.Tables[0].DefaultView;        }
        catch (Exception e)
        {
            throw new Exception(e.Message);
        }    }      public static bool SearchTable(string strSQL)
    {
        SqlDataReader sdr = null;
        try
        {
            openConnection();
            comm.CommandText = strSQL;
            comm.CommandType = CommandType.Text;
            //当 DataReader 处于使用中时，关联的 DbConnection 正忙于为 DataReader 服务。当处于此状态时，除了关闭 Connection 外，不能对其执行其他任何操作。除非调用 DataReader 的 Close 方法，否则会一直处于此状态。如果创建了 DataReader 并将 CommandBehavior 设置为 CloseConnection，则关闭 DataReader 会自动关闭此连接。
            sdr = comm.ExecuteReader(CommandBehavior.CloseConnection);
            if (sdr.Read())
            {                return true;
            }
            else
            {                return false;
            }
        }
        catch
        {
            try
            {
                sdr.Close();
                closeConnection();
            }
            catch
            {
            }
            return false;
        }
        finally
        {
            if (sdr != null)
                sdr.Close();
        }
    }
    //获取Treeview的列表
    //public static void GetDepList(TreeView trAccount,string strSQL)
    //{
    //   try
    //    {
    //        DataView dvdep = GetDataView(strSQL);    //        int dvdepCount = dvdep.Table.Rows.Count - 1;
    //        int i, j, k;
    //        for (i = 0; i <= dvdepCount; i++)
    //        {
    //            TreeNode MainNode = new TreeNode();
    //            MainNode.Checked= true;
    //            MainNode.Text = dvdep.Table.Rows[i][0].ToString();
    //            MainNode.Value = dvdep.Table.Rows[i][0].ToString();
    //            trAccount.Nodes.Add(MainNode);    //        }    //        trAccount.DataSource = dvdep;
    //        trAccount.DataBind();
            
    //    }
    //    catch
    //    {
    //        } 
    //    finally
    //    {
    //        if (dvdep!= null)
    //        {
    //            closeConnection();
    //        }
         
    //    }    // }
    //查找    public static string SearchValue(string strSQl)
    {
        SqlDataReader sdr = null;
        try
        {
            openConnection();
            comm.CommandText = strSQl;
            comm.CommandType = CommandType.Text;
            sdr = comm.ExecuteReader(CommandBehavior.CloseConnection);
            if (sdr.Read())
            {
                return sdr[0].ToString();
            }
            else
                return "";
        }
        catch
        {
            try                                                                                                                                                                                                                          
            {
                sdr.Close();
                closeConnection();
            }
            catch
            { }
            return "";
        }
        finally
        {
            if (sdr != null)
                sdr.Close();
        }
    } 
。以下是报错界面：“/”应用程序中的服务器错误。
--------------------------------------------------------------------------------ExecuteReader: CommandText 属性尚未初始化 
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。 异常详细信息: System.Exception: ExecuteReader: CommandText 属性尚未初始化源错误: 
行 171:        catch (Exception e)
行 172:        {
行 173:            throw new Exception(e.Message);
行 174:        }
行 175:
 源文件: e:\WebSite\OfficeOnLine\App_Code\DBFUN.cs    行: 173 堆栈跟踪: 
[Exception: ExecuteReader: CommandText 属性尚未初始化]
   DBFun.GetDataView(String strSQL) in e:\WebSite\OfficeOnLine\App_Code\DBFUN.cs:173
   filelist.Page_Load(Object sender, EventArgs e) in e:\WebSite\OfficeOnLine\filelist.aspx.cs:39
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +15
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +34
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +47
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1061请问是哪里的错误啊？ 应该怎样改呢？ 小弟是菜鸟，请详细说一下 ，谢谢！
 

解决方案 »

  1.   

    CommandText 属性尚未初始化,初始化下喽
      

  2.   

    CommandText的值为空,或者为NULL, 
    检查下SqlConnection对象,用sqlhelper操作类
    public static SqlConnection ReturnConn()
            {
                conn = new SqlConnection("");
                if (conn.State.Equals(ConnectionState.Closed))
                {
                    conn.Open();
                }
                return conn;
            }
      

  3.   

    你的Sql语句 没有当作参数传入