Fill: SelectCommand.Connection 属性尚未初始化。

[xcywwj]

随便写写。练习的。自己写的类。
老是出现Fill: SelectCommand.Connection 属性尚未初始化。



using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;

namespace DAL
{
public class DBhelpe
{
private static SqlConnection conn;
public static SqlConnection Conn
{
get
{
string connectionString = ConfigurationManager.ConnectionStrings["HB"].ConnectionString;
if (conn == null)
{
conn = new SqlConnection(connectionString);
conn.Open();
}
else if (conn.State == System.Data.ConnectionState.Closed)
{
conn.Open();
}else if(conn.State==System.Data.ConnectionState.Broken)
{
conn.Close();
conn.Open();
}
return conn;
}
}
public static int ExecuteCommand(string sql)
{
SqlCommand com = new SqlCommand(sql,conn);
int num = com.ExecuteNonQuery();
return num;
}
public static int ExecuteCommand(string sql, SqlParameter[] values)
{
SqlCommand com = new SqlCommand(sql, conn);
com.Parameters.AddRange(values);
int num = com.ExecuteNonQuery();
return num;
}
public static SqlDataReader reder(string sql)
{
SqlCommand com = new SqlCommand(sql, conn);
SqlDataReader reder = com.ExecuteReader();
return reder;
}
public static SqlDataReader reder(string sql, SqlParameter[] values)
{
SqlCommand com = new SqlCommand(sql, conn);
com.Parameters.AddRange(values);
SqlDataReader reder = com.ExecuteReader();
return reder;
}
public static DataTable dataTable(string sql)
{
DataSet ds = new DataSet();
SqlCommand com = new SqlCommand(sql, conn);
SqlDataAdapter da = new SqlDataAdapter(com);
da.Fill(ds);
return ds.Tables[0];
}
public static DataTable dataTable(string sql, SqlParameter[] values)
{
DataSet ds = new DataSet();
SqlCommand com = new SqlCommand(sql, conn);
com.Parameters.AddRange(values);
SqlDataAdapter da = new SqlDataAdapter(com);
da.Fill(ds);
return ds.Tables[0];
}
}
}

[dalmeeme]

把SqlCommand com = new SqlCommand(sql,conn);
这种改成SqlCommand com = new SqlCommand(sql,Conn);

你的Connection对象是在属性里初始化的。
另外最好不要用静态的Connection，并发时会有问题。