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List of examples:
// Note: To find the code names of setting keys, open the Modules application in Kentico, edit a module and view the Settings tab
// Gets the value of the "Page not found URL" setting for the current site
string pageNotFoundUrl = SettingsKeyInfoProvider.GetValue(SiteContext.CurrentSiteName + ".CMSPageNotFoundUrl");
// Gets the global value of the "Scheduled tasks enabled" setting
bool scheduledTasksEnabled = SettingsKeyInfoProvider.GetBoolValue("CMSSchedulerTasksEnabled");
// Gets the value of the "Application scheduler interval" setting for the current site
int schedulerInterval = SettingsKeyInfoProvider.GetIntValue(SiteContext.CurrentSiteName + ".CMSSchedulerInterval");// Gets the value of the "CMSApplicationName" key from the appSettings section of the web.config
string webConfigSetting = ValidationHelper.GetString(SettingsHelper.AppSettings["CMSApplicationName"], "");// Sets the value of the "Page not found URL" setting to "~/System-pages/NotFound" for the current site
SettingsKeyInfoProvider.SetValue("CMSPageNotFoundUrl", SiteContext.CurrentSiteName, "~/System-pages/NotFound");
// Sets the value of the global "Scheduled tasks enabled" setting to false
SettingsKeyInfoProvider.SetGlobalValue("CMSSchedulerTasksEnabled", false);
// Sets the value of the "Application scheduler interval" setting to 30 for the current site
SettingsKeyInfoProvider.SetValue("CMSSchedulerInterval", SiteContext.CurrentSiteName, 30);