ThemeItem(String) - свойство

public Object this[
	string propertyName
] { get; set; }

Public Default Property Item ( 
	propertyName As String
) As Object
	Get
	Set

public:
property Object^ default[String^ propertyName] {
	Object^ get (String^ propertyName);
	void set (String^ propertyName, Object^ value);
}

member Item : Object with get, set