菜鸟求解cmd.ExecuteScalar()问题--语法

数据库公共类 SQLClient1定义 数据库连接类 和executescalar定义都在里面
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Data;
using System.Configuration;
/// <summary>
///SQLclient1 的摘要说明
/// </summary>
public class SQLclient1
{

public static readonly string ConnectionStringLocalTransaction =
ConfigurationManager.ConnectionStrings["stdInfoConnectionString"].ConnectionString;

public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{

SqlCommand cmd = new SqlCommand();
using (SqlConnection conn = new SqlConnection(connectionString))
{
PrepareCommand(cmd, conn, null, cmdType, cmdText,
commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}

}
public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
SqlConnection conn = new SqlConnection(connectionString);
try
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
SqlDataReader rdr = cmd.ExecuteReader(
CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return rdr;

}
catch
{
conn.Close();
throw;
}
}
public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText,
params SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
using (SqlConnection connection = new SqlConnection(connectionString))
{
PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}
}
private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText,
SqlParameter[] cmdParms)
{
if (conn.State != ConnectionState.Open)
conn.Open();
cmd.Connection = conn;
cmd.CommandText = cmdText;
if (trans != null)
cmd.CommandType = cmdType;
if (cmdParms != null)
{
foreach (SqlParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}
}





错误页面

错误所在行