In this article, you will learn how to use the connection was not closed. The connection's current state is open.
I think that the error is raised on this line
con.Open(); // InvalidOperationException if it's already openYou are reusing a connection and you probably have not closed it last time
You should always close a connection immediately as soon as you are finished with it, best by using the using-statement
public void run_runcmd(string query)
{
using(var con = new SqlConnection(connectionString))
using(var cmd = new SqlCommand(query, con))
{
con.Open();
// ...
} // close not needed since dispose also closes the connection
}
The connection was not closed. The connection's current state is open.
C# is a programming language developed by Microsoft that runs on the .NET Framework. C# is used to develop web, desktop, mobile, games and much more application.
C# is a object-oriented programming language developed by Microsoft within its .NET Framework. Led by Anders Hejlsberg, your basic C# programming
and will also take you through various advanced concepts related to C# programming language.
C# such as control statements, objects and classes, inheritance, constructor, destructor, this, static, sealed, polymorphism, abstraction, abstract class, interface, File IO, Collections, namespace, encapsulation, properties, indexer, arrays, strings, regex, exception handling, multithreading etc.
For example...
using System;
namespace MinifyCode
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Hello Minify Code");
}
}
}
Output: Hello Minify Code
In this article you will learn, what is server side controls. We will discuss each of these objects in due time. In this tutorial we will explore the Server object, the Request object, and the Response object.
Session
Application
Cache
Request
Response
Server
User
Trace
Server Object
The Server object in Asp.NET is an instance of the System.Web.HttpServerUtility class. The HttpServerUtility class provides numerous properties and methods to perform many type of jobs.
Methods and Properties of the Server object
The methods and properties of the HttpServerUtility class are exposed through the intrinsic Server object provided by ASP.NET.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Optimization;
using System.Web.Routing;
using System.Web.Security;
using System.Web.SessionState;
using System.Data.Entity;
namespace minifycode
{
public class Global : HttpApplication
{
void Application_Start(object sender, EventArgs e)
{
// Code that runs on application startup
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
// Initialize the product database.
Database.SetInitializer(new ProductDatabaseInitializer());
// Create custom role and user.
RoleActions roleActions = new RoleActions();
roleActions.AddUserAndRole();
// Add Routes.
RegisterCustomRoutes(RouteTable.Routes);
}
void RegisterCustomRoutes(RouteCollection routes)
{
routes.MapPageRoute(
"ProductsCategoryRoute",
"Category/{categoryName}",
"~/ProductList.aspx"
);
routes.MapPageRoute(
"ProductNameRoute",
"Product/{productName}",
"~/ProductDetails.aspx"
);
}
}
}