A common task for developers is to store application specific configuration. There are many ways you can take to get that functionality. If you use .Net / C# you can use the simple, built-in way to work with configuration files. Let’s look how this works.
Create an app.config or web.config
Right click on the project node in the Solution Explorer -> Add -> New Item -> Application Configuration File. This will add an app.config file to your project. Visual Studio checks if the project you selected is a web project and if so, it will create a web.config file instead. They follow the same rules and in either case you get the same benefits.
In the app.config file you can add a section called appSettings to store your values. A full example of an app.config with a property to specify a sender email address can look like this one:
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<?xml version="1.0" encoding="utf-8" ?> <configuration> <startup> <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" /> </startup> <connectionStrings> <add name="PagingDb" connectionString="Data Source=.;Initial Catalog=Paging;Integrated Security=SSPI;"/> </connectionStrings> <appSettings> </appSettings> </configuration> |
Use the ConfigurationManager to read it
The class ConfigurationManager offers you a simple way to read the configuration values. Reference the system package System.Configuration and add a using statement for it. You now can read your configuration values like an array:
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var email = ConfigurationManager.AppSettings["SenderEmail"] |
The benefit of storing your configuration values outside of your code is that you can come back later and only change the values in a simple text file. You don’t need to recompile your code to use the new settings.
Reading the connection string
The connection strings for your database have their own section called <connectionStrings>. To read the connection string for the database PagingDb as specified in the app.config example above, you can use this line of code:
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var conn = ConfigurationManager.ConnectionStrings["PagingDb"] .ConnectionString; |
While your configuration settings may not change that much, you should always save your connection strings outside of your application. You should use a different database for development, test and production. If your connection string is stored in the app.config, you can simply replace it without recompiling your code.
Conclusion
When you follow the built-in way and don’t reinvent the configuration management wheel, you not only save a lot of time, but other tools can work with this approach as well (such as Octopus Deploy).
Don’t fight the framework, use it.