What is App.config in C#.NET? How to use it?

Question

I have done a project in C#.NET where my database file is an Excel workbook. Since the location of the connection string is hard coded in my coding, there is no problem for

Answer 1

Simply, App.config is an XML based file format that holds the Application Level Configurations.

Example:

You can access the configurations by using ConfigurationManager as shown in the piece of code snippet below:

var value = System.Configuration.ConfigurationManager.AppSettings["key"];
// value is now "test"

Note: ConfigurationSettings is obsolete method to retrieve configuration information.

var value = System.Configuration.ConfigurationSettings.AppSettings["key"];