ConfigurationElementCollection.BaseAdd Method (ConfigurationElement)
Adds a configuration element to the ConfigurationElementCollection.
Assembly: System.Configuration (in System.Configuration.dll)
When adding, an element is considered a duplicate only if the keys are identical but the values are different. Elements with identical keys and values are accepted silently because the elements do not compete. However, an element with an identical key but a different value cannot be added because there is no logic to determine which of the competing values should be honored.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2