System.Configuration.ConfigurationManager

About

Provides types that support using XML configuration files (app.config). This package exists only to support migrating existing .NET Framework code that already uses System.Configuration. When writing new code, use another configuration system instead, such as Microsoft.Extensions.Configuration.

For more information, see the documentation:

• Configure apps by using configuration files
• System.Configuration namespace
• System.Configuration.Configuration
• System.Configuration.ConfigurationManager

Example

The following example shows how to read and modify the application configuration settings.

using System;
using System.Configuration;

class Program
{
    static void Main()
    {
        try
        {
            // Open current application configuration
            Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            KeyValueConfigurationCollection section = config.AppSettings.Settings;

            // Print settings from configuration file
            foreach (string key in section.AllKeys)
            {
                Console.WriteLine($"{key}: {section[key].Value}");
            }

            // Add new setting
            section.Add("Database", "TestDatabase");

            // Change existing setting
            section["Username"].Value = "TestUser";

            // Save changes to file
            config.Save(ConfigurationSaveMode.Modified);
            ConfigurationManager.RefreshSection(config.AppSettings.SectionInformation.Name);
        }
        catch (ConfigurationErrorsException ex)
        {
            Console.WriteLine("Error reading configuration: ");
            Console.WriteLine(ex.Message);
        }
    }
}

To run this example, include an app.config file with the following content in your project:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="Server" value="example.com"/>
    <add key="Username" value="Admin"/>
  </appSettings>
</configuration>