Asp.net 连接关闭错误
我在这段代码中有两个DataReader，vs给我这个错误“连接没有关闭。连接的当前状态是打开的。”错误来自connection2。我查看了我的代码，但我的两个连接已关闭。问题在哪里Asp.net 连接关闭错误,asp.net,sql-server-2008-r2,Asp.net,Sql Server 2008 R2,我在这段代码中有两个DataReader，vs给我这个错误“连接没有关闭。连接的当前状态是打开的。”错误来自connection2。我查看了我的代码，但我的两个连接已关闭。问题在哪里 protected void Page_Load(object sender, EventArgs e) { using (SqlConnection connection1 = DBConnection.getConnection()) { string strquer
protected void Page_Load(object sender, EventArgs e)
{
using (SqlConnection connection1 = DBConnection.getConnection())
{
string strquery1 = " with distinctvalueyes (typearticle) as (select top 1 'Fruit' FROM WeedingSalonGeneralRes where Fruit=1 union all select top 1 'Drink' FROM WeedingSalonGeneralRes where Drink=1 union all select top 1 'Desert' FROM WeedingSalonGeneralRes where Desert=1 union all select top 1 'MainFood' FROM WeedingSalonGeneralRes where MainFood=1 union all select top 1 'Salad' FROM WeedingSalonGeneralRes where Salad=1 union all select top 1 'TableFlower' FROM WeedingSalonGeneralRes where TableFlower=1 union all select top 1 'SaloonLighting' FROM WeedingSalonGeneralRes where SaloonLighting=1 union all select top 1 'Saloondesign' FROM WeedingSalonGeneralRes where Saloondesign=1 union all select top 1 'SloonCrew' FROM WeedingSalonGeneralRes where SloonCrew=1 union all select top 1 'Pastry' FROM WeedingSalonGeneralRes where Pastry=1 union all select top 1 'GiftCard' FROM WeedingSalonGeneralRes where GiftCard=1 ) select * from distinctvalueyes ";
connection1.Open();
SqlCommand cmd1 = new SqlCommand();
cmd1.Connection = connection1;
cmd1.CommandText = strquery1;
string cis = Session["customerID"].ToString();
lbl2_customerid.Text = cis;
SqlDataReader reader = cmd1.ExecuteReader();
if (reader.Read())
{
lbl8_fruit.Text = reader[0].ToString();
// wrapped in a using block, connection will now always be closed and disposed
using (SqlConnection connection2 = DBConnection.getConnection())
{
//query for fetch service prices
string strquery2 = "SELECT Fruit_price,Drink_price,Desert_price,MainFood_price,Salad_price,TableFlower_price,SaloonLighting_price,SaloonDesign_price,SaloonCrew_price,Pastry_price,GiftCard_price FROM GenReservationServicePrice";
connection2.Open();
SqlCommand cmd2 = new SqlCommand();
cmd2.Connection = connection2;
cmd2.CommandText = strquery2;
SqlDataReader reader2 = cmd2.ExecuteReader();
if (reader2.Read())
{
string Fruit_price;
string Drink_price;
string Desert_price;
string MainFood_price;
string Salad_price;
string TableFlower_price;
string SaloonLighting_price;
string SaloonDesign_price;
string SaloonCrew_price;
string Pastry_price;
string GiftCard_price;
Fruit_price = reader[0].ToString();
Drink_price = reader[1].ToString();
Desert_price = reader[2].ToString();
MainFood_price = reader[3].ToString();
Salad_price = reader[4].ToString();
TableFlower_price = reader[5].ToString();
SaloonLighting_price = reader[6].ToString();
SaloonDesign_price = reader[7].ToString();
SaloonCrew_price = reader[8].ToString();
Pastry_price = reader[9].ToString();
GiftCard_price = reader[10].ToString();
lbl8_fruit.Text = Fruit_price;
}
}
}
}
}
///connection class
public class DBConnection
{
private static SqlConnection connection=null;
public DBConnection()
{
}
public static SqlConnection getConnection()
{
if (connection != null)
{ return connection; }
else
{
String connectionString = WebConfigurationManager.AppSettings["connectionString"];
connection = new SqlConnection(connectionString);
return connection;
}
}
SqlConnectionSqlConnection- 创造它
- 使用它
- 处理它
///connection class
public class DBConnection
{
public static SqlConnection getConnection()
{
String connectionString = WebConfigurationManager.AppSettings["connectionString"];
return new SqlConnection(connectionString);
}
}
SqlConnectionsusing使用SqlConnection 您应该使用
块将所有SqlConnection
实例包装在中。这将确保即使发生异常，连接也始终处于关闭和释放状态。它还需要对代码执行所有检查工作，无需查看代码是否在关闭时打开
这是您使用块更改的代码，我删除了您的一些逻辑，所以很清楚我更改了什么
protected void Page_Load(object sender, EventArgs e)
{
/* your existing code removed for clarit */
// wrapped in a using block, connection will now always be closed and disposed
using(SqlConnection connection1 = DBConnection.getConnection())
{
connection1.Open();
SqlCommand cmd1 = new SqlCommand();
cmd1.Connection = connection1;
cmd1.CommandText = strquery1;
string cis = Session["customerID"].ToString();
lbl2_customerid.Text = cis;
SqlDataReader reader = cmd1.ExecuteReader();
if (reader.Read())
{
/* your existing code removed for clarit */
// wrapped in a using block, connection will now always be closed and disposed
using(SqlConnection connection2 = DBConnection.getConnection())
{
connection2.Open();
SqlCommand cmd2 = new SqlCommand();
cmd2.Connection = connection2;
cmd2.CommandText = strquery2;
SqlDataReader reader2 = cmd2.ExecuteReader();
if (reader2.Read())
{
/* your existing code removed for clarit */
}
}
}
}
}
编辑
问题是您试图在两个位置使用相同的SqlConnection
实例。每次需要时，都应该使用新的SqlConnection
- 创造它
- 使用它
- 处理它
代码更改：
///connection class
public class DBConnection
{
public static SqlConnection getConnection()
{
String connectionString = WebConfigurationManager.AppSettings["connectionString"];
return new SqlConnection(connectionString);
}
}
Sql Server有一种称为连接池的功能，默认情况下会启用这种功能。在c#中创建连接将重用Sql Server上已经可用的连接，因此此操作非常便宜。将所有使用SqlConnections
的代码包装在using
块中，以确保它们始终处于关闭状态，从而不会发生连接泄漏
此外，app.config/web.config还有一个。你应该使用它，而不是应用程序设置
使用SqlConnection
您应该使用块将所有SqlConnection
实例包装在中。这将确保即使发生异常，连接也始终处于关闭和释放状态。它还需要对代码执行所有检查工作，无需查看代码是否在关闭时打开
这是您使用块更改的代码，我删除了您的一些逻辑，所以很清楚我更改了什么
protected void Page_Load(object sender, EventArgs e)
{
/* your existing code removed for clarit */
// wrapped in a using block, connection will now always be closed and disposed
using(SqlConnection connection1 = DBConnection.getConnection())
{
connection1.Open();
SqlCommand cmd1 = new SqlCommand();
cmd1.Connection = connection1;
cmd1.CommandText = strquery1;
string cis = Session["customerID"].ToString();
lbl2_customerid.Text = cis;
SqlDataReader reader = cmd1.ExecuteReader();
if (reader.Read())
{
/* your existing code removed for clarit */
// wrapped in a using block, connection will now always be closed and disposed
using(SqlConnection connection2 = DBConnection.getConnection())
{
connection2.Open();
SqlCommand cmd2 = new SqlCommand();
cmd2.Connection = connection2;
cmd2.CommandText = strquery2;
SqlDataReader reader2 = cmd2.ExecuteReader();
if (reader2.Read())
{
/* your existing code removed for clarit */
}
}
}
}
}
获取连接2.Close（）；在if语句之外。我移动connection2.Close（）；在if语句之外，但我再次遇到了错误，请尝试封闭从connection2.Open（）开始的第二个块；在使用块中；使用（SqlConnection connection2=DBConnection.getConnection（））{connection2.Open（）；…}并删除connection2.Close（）；你的意思是我使用一个连接所有人？你不是从不同的数据库中提取数据，对吗。所以，是的，所有人都有一个连接。我会把if语句改为while语句。因此，代替if（reader.Read（））{..}，而（reader.Read（））{..}获取connection2.Close（）；在if语句之外。我移动connection2.Close（）；在if语句之外，但我再次遇到了错误，请尝试封闭从connection2.Open（）开始的第二个块；在使用块中；使用（SqlConnection connection2=DBConnection.getConnection（））{connection2.Open（）；…}并删除connection2.Close（）；你的意思是我使用一个连接所有人？你不是从不同的数据库中提取数据，对吗。所以，是的，所有人都有一个连接。我会把if语句改为while语句。因此，我使用这些代码进行测试，而不是if（reader.Read（））{..}而（reader.Read（））{..}时出现了错误。我通过一步一步地调试和连接2.Open（）进行测试；错误是shown@meysam-DBConnection.getConnection的作用是什么？你能提供那个代码吗？如果它每次都返回一个静态连接实例（即同一个实例），那么这就是问题所在，就像您试图更改已经打开的连接的状态一样。我使用这些代码进行测试，我发现了错误。我通过一步一步地调试和连接2.Open（）进行测试；错误是shown@meysam-DBConnection.getConnection的作用是什么？你能提供那个代码吗？如果它每次都返回一个静态连接实例（即同一个实例），那么这就是问题所在，就像您试图更改已打开连接的状态一样。