Custom ASP.NET SqlMembershipProvider - handling connection string - asp.net-membership

Question

I am creating a custom SqlMembershipProvider class to add some enhanced functionality to the base class. I'm getting caught up on handling the connection string, though. How can I read the Connection String Name from the configuration and make that available to the rest of the methods?
Right now I have:
public override void Initialize(string name, NameValueCollection config)
{
base.Initialize(name, config);
_ConnectionStringName = config["connectionStringName"];
}
But in other methods, the _ConnectionStringName variable is null:
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings[_ConnectionStringName].ConnectionString)
What is the proper way to store the Connection String Name so it is available globally in my custom membership provider?
Thanks!

Answer 1

ProviderBase will throw a ConfigurationException if there are any entries left in the config collection by the time it get's it so each provider removes it's configuration entries before calling base.Initialize.
The issue, as you have found as a result of this answer is that you must get your values before calling base.Initialize.
Sorry, I missed that at first glance.
The rest of this post is historical and while technically correct misses the salient issue here as enumerated above.
First - try WebConfigurationManager.ConnectionStrings.
WebConfigurationManager handles applying the hierarchy of web.config all the way from your windows\microsoft.net\framework\2.0xxxx\web.config all the way up to your app.
This behaviour is not present in ConfigurationManager, which typically deals with machine.config to app.config.
If this does not solve your problem you must be overwriting the value elsewhere in your code, if indeed _ConnectionStringName is being properly assigned in Initialize.
First, set a breakpoint and ensure that _ConnectionStringName is being set as expected.
Then locate all references to the field and ensure that you do not have a bug.
This is assuming, of course, that _ConnectionStringName is a private field. If it is not, make it so and look for your compile error.

Answer 2

Not sure if this helps, but I was having a similar issue in needing to override the connectionstring in a sub-class of SqlMembershipProvider.
This idea is not my own - I found it in the comments section of this forum posting:
http://forums.asp.net/p/997608/2209437.aspx
public override void Initialize(string name, NameValueCollection config)
{
base.Initialize(name, config);<br>
string connectionString = //...what you want your connection string to be,
//so config["connectionStringName"]...
// Set private property of Membership provider.
System.Reflection.FieldInfo connectionStringField =
GetType().BaseType.GetField("_sqlConnectionString",
System.Reflection.BindingFlags.Instance
| System.Reflection.BindingFlags.NonPublic);
connectionStringField.SetValue(this, connectionString);
}
My apologies - I've never posted here before, so the formatting may be sub-par!

Answer 3

This is probably 6 months too late to help, but I was able to get the connection string this way:
using System.Web.Configuration;
Configuration config = WebConfigurationManager.OpenWebConfiguration("~");
MembershipSection section = config.SectionGroups["system.web"].Sections["membership"] as MembershipSection;
string defaultProvider = section.DefaultProvider;
string connstringName = section.Providers[defaultProvider].ElementInformation.Properties["connectionStringName"].Value.ToString();
string val = config.ConnectionStrings.ConnectionStrings[connstringName].ConnectionString;
This makes the assumption that the default provider has a connection string property - but if you're subclassing SqlMembershipProvider then should always have one, somewhere up the web.config chain (it's defined in the machine.config I believe).
All of this, to add one method to change the username.