configurationManager does not exist in the namespace System.Configuration
C#Sql ServerVisual Studio-2005C# Problem Overview
I have used the following namespace to connect my project to the sql server:
using System.Configuration;
and also used
string str=System.Configuration.ConfigurationSettings.AppSettings["myconnection"];
SqlConnection oconnection = new SqlConnection(str);
oconnection.Open();
when I run the program ,an error has been occurred and show the message
> 'System.Configuration.ConfigurationSettings.AppSettings' is > obsolete.This method is obsolete,it has been replaced by > 'System.Configuration! > System.Configuration.ConfigurationManager.AppSettings '
but I have no found ConfigurationManager in that namespace and for oconnection.Open();
the message is
> InvalidOperationException
was unhandled.
What can I do?
C# Solutions
Solution 1 - C#
Go to references, and add a reference to System.Configuration
Once you have done this, you should be able to reference System.Configuration.ConfigurationManager
.
string str = System.Configuration.ConfigurationManager.AppSettings["myconnection"];
SqlConnection oconnection = new SqlConnection(str);
oconnection.Open();
From MSDN:
The ConfigurationManager
class enables you to access machine, application, and user configuration information. This class replaces the ConfigurationSettings
class, which is deprecated.
http://msdn.microsoft.com/en-us/library/system.configuration.configurationmanager.aspx
Edit: Addiitonal Information
In reference to the InvalidOperationException
. This is caused when the connection string does not specify a data source or server. I am guessing that your connection string is empty.
In your web.config check the location of your connection string. If it falls under the ConnectionStrings
and not AppSettings
.
string str = System.Configuration.ConfigurationManager.
ConnectionStrings["myconnection"].ConnectionString;
Solution 2 - C#
If you have multiple projects in the solution you have to add the reference System.Configuration
to each of them for ConfigurationManager
to work in any of them.
Solution 3 - C#
Add a reference of : System.Configuration.dll in your project, then ConfigurationManager will be availiable
Solution 4 - C#
Install System.Configuration from nuget package. Then add reference.