<PackageReference Include="System.Configuration.ConfigurationManager" Version="10.0.2" />

System.Configuration.SettingChangingEventArgs

Provides data for the SettingChanging event.
namespace System.Configuration { public class SettingChangingEventArgs : CancelEventArgs { public object NewValue { get; } public string SettingClass { get; } public string SettingName { get; } public string SettingKey { get; } public SettingChangingEventArgs(string settingName, string settingClass, string settingKey, object newValue, bool cancel); } }