src/libraries/System.Configuration.ConfigurationManager/src/PACKAGE.md
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.
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>
The main types provided by this library are:
System.Configuration.ConfigurationSystem.Configuration.ConfigurationManagerSystem.Configuration.ConfigurationManager is released as open source under the MIT license. Bug reports and contributions are welcome at the GitHub repository.