combobox.tex

很牛的GUI源码wxWidgets-2.8.0.zip 可在多种平台下运行.

\section{\class{wxComboBox}}\label{wxcombobox}

A combobox is like a combination of an edit control and a listbox. It can be
displayed as static list with editable or read-only text field; or a drop-down list with
text field; or a drop-down list without a text field.

A combobox permits a single selection only. Combobox items are numbered from zero.

If you need a customized combobox, have a look at \helpref{wxComboCtrl}{wxcomboctrl},
\helpref{wxOwnerDrawnComboBox}{wxownerdrawncombobox}, \helpref{wxComboPopup}{wxcombopopup}
and the ready-to-use \helpref{wxBitmapComboBox}{wxbitmapcombobox}.

\wxheading{Derived from}

\helpref{wxControlWithItems}{wxcontrolwithitems}\\
\helpref{wxControl}{wxcontrol}\\
\helpref{wxWindow}{wxwindow}\\
\helpref{wxEvtHandler}{wxevthandler}\\
\helpref{wxObject}{wxobject}

\wxheading{Include files}

<wx/combobox.h>

\wxheading{Window styles}

\begin{twocollist}\itemsep=0pt
\twocolitem{\windowstyle{wxCB\_SIMPLE}}{Creates a combobox with a permanently displayed list. Windows only. }
\twocolitem{\windowstyle{wxCB\_DROPDOWN}}{Creates a combobox with a drop-down list.}
\twocolitem{\windowstyle{wxCB\_READONLY}}{Same as wxCB\_DROPDOWN but only the
strings specified as the combobox choices can be selected, it is impossible to
select (even from a program) a string which is not in the choices list.}
\twocolitem{\windowstyle{wxCB\_SORT}}{Sorts the entries in the list alphabetically.}
\twocolitem{\windowstyle{wxTE\_PROCESS\_ENTER}}{The control will generate
the event wxEVT\_COMMAND\_TEXT\_ENTER (otherwise pressing Enter key
is either processed internally by the control or used for navigation between
dialog controls). Windows only.}
\end{twocollist}

See also \helpref{window styles overview}{windowstyles}.

\wxheading{Event handling}

\twocolwidtha{7cm}
\begin{twocollist}\itemsep=0pt
\twocolitem{{\bf EVT\_COMBOBOX(id, func)}}{Process a wxEVT\_COMMAND\_COMBOBOX\_SELECTED event,
when an item on the list is selected. Note that calling
\helpref{GetValue}{wxcomboboxgetvalue} returns the new value of selection.}
\twocolitem{{\bf EVT\_TEXT(id, func)}}{Process a wxEVT\_COMMAND\_TEXT\_UPDATED event,
when the combobox text changes.}
\twocolitem{{\bf EVT\_TEXT\_ENTER(id, func)}}{Process a wxEVT\_COMMAND\_TEXT\_ENTER event,
when <RETURN> is pressed in the combobox.}
\end{twocollist}

\wxheading{See also}

\helpref{wxListBox}{wxlistbox}, \helpref{wxTextCtrl}{wxtextctrl}, \helpref{wxChoice}{wxchoice},
\rtfsp\helpref{wxCommandEvent}{wxcommandevent}

\latexignore{\rtfignore{\wxheading{Members}}}


\membersection{wxComboBox::wxComboBox}\label{wxcomboboxctor}

\func{}{wxComboBox}{\void}

Default constructor.

\func{}{wxComboBox}{\param{wxWindow*}{ parent}, \param{wxWindowID}{ id},\rtfsp
\param{const wxString\& }{value = ``"}, \param{const wxPoint\&}{ pos = wxDefaultPosition}, \param{const wxSize\&}{ size = wxDefaultSize},\rtfsp
\param{int}{ n = 0}, \param{const wxString }{choices[] = NULL},\rtfsp
\param{long}{ style = 0}, \param{const wxValidator\& }{validator = wxDefaultValidator}, \param{const wxString\& }{name = ``comboBox"}}

\func{}{wxComboBox}{\param{wxWindow*}{ parent}, \param{wxWindowID}{ id},\rtfsp
\param{const wxString\& }{value}, \param{const wxPoint\&}{ pos}, \param{const wxSize\&}{ size},\rtfsp
\param{const wxArrayString\& }{choices},\rtfsp
\param{long}{ style = 0}, \param{const wxValidator\& }{validator = wxDefaultValidator}, \param{const wxString\& }{name = ``comboBox"}}

Constructor, creating and showing a combobox.

\wxheading{Parameters}

\docparam{parent}{Parent window. Must not be NULL.}

\docparam{id}{Window identifier. A value of -1 indicates a default value.}

\docparam{value}{Initial selection string. An empty string indicates no selection.}

\docparam{pos}{Window position.}

\docparam{size}{Window size. If the default size (-1, -1) is specified then the window is sized
appropriately.}

\docparam{n}{Number of strings with which to initialise the control.}

\docparam{choices}{An array of strings with which to initialise the control.}

\docparam{style}{Window style. See \helpref{wxComboBox}{wxcombobox}.}

\docparam{validator}{Window validator.}

\docparam{name}{Window name.}

\wxheading{See also}

\helpref{wxComboBox::Create}{wxcomboboxcreate}, \helpref{wxValidator}{wxvalidator}

\pythonnote{The wxComboBox constructor in wxPython reduces the {\tt n}
and {\tt choices} arguments are to a single argument, which is
a list of strings.}

\perlnote{In wxPerl there is just an array reference in place of {\tt n}
and {\tt choices}.}


\membersection{wxComboBox::\destruct{wxComboBox}}\label{wxcomboboxdtor}

\func{}{\destruct{wxComboBox}}{\void}

Destructor, destroying the combobox.


\membersection{wxComboBox::Create}\label{wxcomboboxcreate}

\func{bool}{Create}{\param{wxWindow*}{ parent}, \param{wxWindowID}{ id},\rtfsp
\param{const wxString\& }{value = ``"}, \param{const wxPoint\&}{ pos = wxDefaultPosition}, \param{const wxSize\&}{ size = wxDefaultSize},\rtfsp
\param{int}{ n}, \param{const wxString }{choices[]},\rtfsp
\param{long}{ style = 0}, \param{const wxValidator\& }{validator = wxDefaultValidator}, \param{const wxString\& }{name = ``comboBox"}}

\func{bool}{Create}{\param{wxWindow*}{ parent}, \param{wxWindowID}{ id},\rtfsp
\param{const wxString\& }{value}, \param{const wxPoint\&}{ pos}, \param{const wxSize\&}{ size},\rtfsp
\param{const wxArrayString\& }{choices},\rtfsp
\param{long}{ style = 0}, \param{const wxValidator\& }{validator = wxDefaultValidator}, \param{const wxString\& }{name = ``comboBox"}}

Creates the combobox for two-step construction. Derived classes
should call or replace this function. See \helpref{wxComboBox::wxComboBox}{wxcomboboxctor}\rtfsp
for further details.


\membersection{wxComboBox::CanCopy}\label{wxcomboboxcancopy}

\constfunc{bool}{CanCopy}{\void}

Returns true if the combobox is editable and there is a text selection to copy to the clipboard.
Only available on Windows.


\membersection{wxComboBox::CanCut}\label{wxcomboboxcancut}

\constfunc{bool}{CanCut}{\void}

Returns true if the combobox is editable and there is a text selection to copy to the clipboard.
Only available on Windows.


\membersection{wxComboBox::CanPaste}\label{wxcomboboxcanpaste}

\constfunc{bool}{CanPaste}{\void}

Returns true if the combobox is editable and there is text on the clipboard that can be pasted into the
text field. Only available on Windows.


\membersection{wxComboBox::CanRedo}\label{wxcomboboxcanredo}

\constfunc{bool}{CanRedo}{\void}

Returns true if the combobox is editable and the last undo can be redone.
Only available on Windows.


\membersection{wxComboBox::CanUndo}\label{wxcomboboxcanundo}

\constfunc{bool}{CanUndo}{\void}

Returns true if the combobox is editable and the last edit can be undone.
Only available on Windows.


\membersection{wxComboBox::Copy}\label{wxcomboboxcopy}

\func{void}{Copy}{\void}

Copies the selected text to the clipboard.


\membersection{wxComboBox::Cut}\label{wxcomboboxcut}

\func{void}{Cut}{\void}

Copies the selected text to the clipboard and removes the selection.


\membersection{wxComboBox::GetCurrentSelection}\label{wxcomboboxgetcurrentselection}

\constfunc{int}{GetCurrentSelection}{\void}

This function does the same things as 
\helpref{wxChoice::GetCurrentSelection}{wxchoicegetcurrentselection} and
returns the item currently selected in the dropdown list if it's open or the
same thing as \helpref{GetSelection}{wxcontrolwithitemsgetselection} otherwise.


\membersection{wxComboBox::GetInsertionPoint}\label{wxcomboboxgetinsertionpoint}

\constfunc{long}{GetInsertionPoint}{\void}

Returns the insertion point for the combobox's text field.

\textbf{Note:} Under wxMSW, this function always returns $0$ if the combobox
doesn't have the focus.


\membersection{wxComboBox::GetLastPosition}\label{wxcomboboxgetlastposition}

\constfunc{virtual wxTextPos}{GetLastPosition}{\void}

Returns the last position in the combobox text field.


\membersection{wxComboBox::GetSelection}\label{wxcomboboxgetselection}

\constfunc{void}{GetSelection}{\param{long *}{from}, \param{long *}{to}}

This is the same as \helpref{wxTextCtrl::GetSelection}{wxtextctrlgetselection} 
for the text control which is part of the combobox. Notice that this is a
different method from \helpref{wxControlWithItems::GetSelection}{wxcontrolwithitemsgetselection}.

Currently this method is only implemented in wxMSW and wxGTK.


\membersection{wxComboBox::GetValue}\label{wxcomboboxgetvalue}

\constfunc{wxString}{GetValue}{\void}

Returns the current value in the combobox text field.


\membersection{wxComboBox::Paste}\label{wxcomboboxpaste}

\func{void}{Paste}{\void}

Pastes text from the clipboard to the text field.


\membersection{wxComboBox::Redo}\label{wxcomboboxredo}

\func{void}{Redo}{\void}

Redoes the last undo in the text field. Windows only.


\membersection{wxComboBox::Replace}\label{wxcomboboxreplace}

\func{void}{Replace}{\param{long}{ from}, \param{long}{ to}, \param{const wxString\& }{text}}

Replaces the text between two positions with the given text, in the combobox text field.

\wxheading{Parameters}

\docparam{from}{The first position.}

\docparam{to}{The second position.}

\docparam{text}{The text to insert.}


\membersection{wxComboBox::Remove}\label{wxcomboboxremove}

\func{void}{Remove}{\param{long}{ from}, \param{long}{ to}}

Removes the text between the two positions in the combobox text field.

\wxheading{Parameters}

\docparam{from}{The first position.}

\docparam{to}{The last position.}


\membersection{wxComboBox::SetInsertionPoint}\label{wxcomboboxsetinsertionpoint}

\func{void}{SetInsertionPoint}{\param{long}{ pos}}

Sets the insertion point in the combobox text field.

\wxheading{Parameters}

\docparam{pos}{The new insertion point.}


\membersection{wxComboBox::SetInsertionPointEnd}\label{wxcomboboxsetinsertionpointend}

\func{void}{SetInsertionPointEnd}{\void}

Sets the insertion point at the end of the combobox text field.


\membersection{wxComboBox::SetSelection}\label{wxcomboboxsetselection}

\func{void}{SetSelection}{\param{long}{ from}, \param{long}{ to}}

Selects the text between the two positions, in the combobox text field.

\wxheading{Parameters}

\docparam{from}{The first position.}

\docparam{to}{The second position.}

\pythonnote{This method is called {\tt SetMark} in wxPython, {\tt SetSelection}
name is kept for
\helpref{wxControlWithItems::SetSelection}{wxcontrolwithitemssetselection}.}


\membersection{wxComboBox::SetValue}\label{wxcomboboxsetvalue}

\func{void}{SetValue}{\param{const wxString\& }{text}}

Sets the text for the combobox text field.

{\bf NB:} For a combobox with {\tt wxCB\_READONLY} style the string must be in
the combobox choices list, otherwise the call to SetValue() is ignored.

\wxheading{Parameters}

\docparam{text}{The text to set.}


\membersection{wxComboBox::Undo}\label{wxcomboboxundo}

\func{void}{Undo}{\void}

Undoes the last edit in the text field. Windows only.