Change a web.config programmatically with C# (.NET)

Question

How can I modify / manipulate the web.config programmatically with C# ? Can I use a configuration object, and, if yes, how can I load the web.config into a configuration object ? I would like to have a full example changing the connection string. After the modification the web.config should be written back to the harddisk.

Answer 1

Check his blog post about how to Programmatically manipulating web.config in ASP.NET 2.0 and ASP.NET 3.5

Alternatively check this question which has the answer for your question.

How do I set a connection string config programatically in .net?

Took me few seconds to google it. You could have done it than waiting and posting the question again today.

Answer 2

Here it is some code:

var configuration = WebConfigurationManager.OpenWebConfiguration("~");
var section = (ConnectionStringsSection)configuration.GetSection("connectionStrings");
section.ConnectionStrings["MyConnectionString"].ConnectionString = "Data Source=...";
configuration.Save();

See more examples in this article, you may need to take a look to impersonation.

Answer 3

Configuration config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~");
        ConnectionStringsSection section = config.GetSection("connectionStrings") as ConnectionStringsSection;
        //section.SectionInformation.UnprotectSection();
        section.SectionInformation.ProtectSection("DataProtectionConfigurationProvider");
        config.Save();

Blockquote

Answer 4

Since web.config file is xml file you can open web.config using xmldocument class. Get the node from that xml file that you want to update and then save xml file.

here is URL that explains in more detail how you can update web.config file programmatically.

http://patelshailesh.com/index.php/update-web-config-programmatically

Note: if you make any changes to web.config, ASP.NET detects that changes and it will reload your application(recycle application pool) and effect of that is data kept in Session, Application, and Cache will be lost (assuming session state is InProc and not using a state server or database).