\section{\class{wxClientData}}\label{wxclientdata} All classes deriving from \helpref{wxEvtHandler}{wxevthandler} (such as all controls and \helpref{wxApp}{wxapp}) can hold arbitrary data which is here referred to as "client data". This is useful e.g. for scripting languages which need to handle shadow objects for most of wxWidgets' classes and which store a handle to such a shadow class as client data in that class. This data can either be of type void - in which case the data {\it container} does not take care of freeing the data again or it is of type wxClientData or its derivatives. In that case the container (e.g. a control) will free the memory itself later. Note that you {\it must not} assign both void data and data derived from the wxClientData class to a container. Some controls can hold various items and these controls can additionally hold client data for each item. This is the case for \helpref{wxChoice}{wxchoice}, \helpref{wxComboBox}{wxcombobox} and \helpref{wxListBox}{wxlistbox}. \helpref{wxTreeCtrl}{wxtreectrl} has a specialized class \helpref{wxTreeItemData}{wxtreeitemdata} for each item in the tree. If you want to add client data to your own classes, you may use the mix-in class \helpref{wxClientDataContainer}{wxclientdatacontainer}. \wxheading{Include files} \wxheading{See also} \helpref{wxEvtHandler}{wxevthandler}, \helpref{wxTreeItemData}{wxtreeitemdata}, \helpref{wxStringClientData}{wxstringclientdata}, \helpref{wxClientDataContainer}{wxclientdatacontainer} \latexignore{\rtfignore{\wxheading{Members}}} \membersection{wxClientData::wxClientData}\label{wxclientdatawxclientdata} \func{}{wxClientData}{\void} Constructor. \membersection{wxClientData::\destruct{wxClientData}}\label{wxclientdatadtor} \func{}{\destruct{wxClientData}}{\void} Virtual destructor. \section{\class{wxClientDataContainer}}\label{wxclientdatacontainer} This class is a mixin that provides storage and management of "client data." This data can either be of type void - in which case the data {\it container} does not take care of freeing the data again or it is of type wxClientData or its derivatives. In that case the container will free the memory itself later. Note that you {\it must not} assign both void data and data derived from the wxClientData class to a container. NOTE: This functionality is currently duplicated in wxEvtHandler in order to avoid having more than one vtable in that class hierarchy. \wxheading{See also} \helpref{wxEvtHandler}{wxevthandler}, \helpref{wxClientData}{wxclientdata} \wxheading{Derived from} No base class \wxheading{Include files} \wxheading{Data structures} \latexignore{\rtfignore{\wxheading{Members}}} \membersection{wxClientDataContainer::wxClientDataContainer}\label{wxclientdatacontainerwxclientdatacontainer} \func{}{wxClientDataContainer}{\void} \membersection{wxClientDataContainer::\destruct{wxClientDataContainer}}\label{wxclientdatacontainerdtor} \func{}{\destruct{wxClientDataContainer}}{\void} \membersection{wxClientDataContainer::GetClientData}\label{wxclientdatacontainergetclientdata} \constfunc{void*}{GetClientData}{\void} Get the untyped client data. \membersection{wxClientDataContainer::GetClientObject}\label{wxclientdatacontainergetclientobject} \constfunc{wxClientData*}{GetClientObject}{\void} Get a pointer to the client data object. \membersection{wxClientDataContainer::SetClientData}\label{wxclientdatacontainersetclientdata} \func{void}{SetClientData}{\param{void* }{data}} Set the untyped client data. \membersection{wxClientDataContainer::SetClientObject}\label{wxclientdatacontainersetclientobject} \func{void}{SetClientObject}{\param{wxClientData* }{data}} Set the client data object. Any previous object will be deleted.