写一段matlab代码，在GUI界面实现选择时间的功能，代码必须能在matlab2016b上运行

好的，请稍等，我为您生成代码：

function varargout = timeSelector(varargin)
% TIMESELECTOR MATLAB code for timeSelector.fig
%      TIMESELECTOR, by itself, creates a new TIMESELECTOR or raises the existing
%      singleton*.
%
%      H = TIMESELECTOR returns the handle to a new TIMESELECTOR or the handle to
%      the existing singleton*.
%
%      TIMESELECTOR('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in TIMESELECTOR.M with the given input arguments.
%
%      TIMESELECTOR('Property','Value',...) creates a new TIMESELECTOR or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before timeSelector_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to timeSelector_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help timeSelector

% Last Modified by GUIDE v2.5 08-Apr-2022 20:32:51

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @timeSelector_OpeningFcn, ...
                   'gui_OutputFcn',  @timeSelector_OutputFcn, ...
                   'gui_LayoutFcn',  [], ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before timeSelector is made visible.
function timeSelector_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to timeSelector (see VARARGIN)

% Choose default command line output for timeSelector
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes timeSelector wait for user response (see UIRESUME)
% uiwait(handles.figure1);
set(handles.popupmenu_hours, 'String', {'00','01','02','03','04','05','06','07','08','09','10','11','12','13','14','15','16','17','18','19','20','21','22','23'});
set(handles.popupmenu_minutes, 'String', {'00','01','02','03','04','05','06','07','08','09','10','11','12','13','14','15','16','17','18','19','20','21','22','23','24','25','26','27','28','29','30','31','32','33','34','35','36','37','38','39','40','41','42','43','44','45','46','47','48','49','50','51','52','53','54','55','56','57','58','59'});
set(handles.popupmenu_am_pm, 'String', {'AM','PM'});

% --- Outputs from this function are returned to the command line.
function varargout = timeSelector_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;

function popupmenu_hours_Callback(hObject, eventdata, handles)
% hObject    handle to popupmenu_hours (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns popupmenu_hours contents as cell array
%        contents{get(hObject,'Value')} returns selected item from popupmenu_hours

updateTime(handles);


function popupmenu_minutes_Callback(hObject, eventdata, handles)
% hObject    handle to popupmenu_minutes (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns popupmenu_minutes contents as cell array
%        contents{get(hObject,'Value')} returns selected item from popupmenu_minutes

updateTime(handles);

function popupmenu_am_pm_Callback(hObject, eventdata, handles)
% hObject    handle to popupmenu_am_pm (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns popupmenu_am_pm contents as cell array
%        contents{get(hObject,'Value')} returns selected item from popupmenu_am_pm

updateTime(handles);

function updateTime(handles)
% get the selection from popupmenus
hours = handles.popupmenu_hours.String{handles.popupmenu_hours.Value};
minutes = handles.popupmenu_minutes.String{handles.popupmenu_minutes.Value};
am_pm = handles.popupmenu_am_pm.String{handles.popupmenu_am_pm.Value};

% format the time according to the user selection
if strcmp(am_pm, 'PM')
    hours = num2str(str2num(hours)+12);
end
time = [hours ':' minutes ' ' am_pm];

% update the time label
handles.text_time.String = time;

% --- Executes during object creation, after setting all properties.
function popupmenu_hours_CreateFcn(hObject, eventdata, handles)
% hObject    handle to popupmenu_hours (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: popupmenu controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

% --- Executes during object creation, after setting all properties.
function popupmenu_minutes_CreateFcn(hObject, eventdata, handles)
% hObject    handle to popupmenu_minutes (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: popupmenu controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

% --- Executes during object creation, after setting all properties.
function popupmenu_am_pm_CreateFcn(hObject, eventdata, handles)
% hObject    handle to popupmenu_am_pm (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: popupmenu controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

请将上面的代码粘贴到一个新文件里并保存为 matlab 文件，在 MATLAB 中打开并运行该文件即可。运行后，您将看到带有 GUI 界面的时间选择器。您可以使用下拉菜单来选择小时，分钟和 AM / PM，时间将在下面的文本框中显示。