课后习题_MATLAB仿真及在电子信息与电气工程中的应用_[共2页]

第7章MATLAB图形用户界面153 % --- Executes on selection change in popupmenu1
function popupmenu1_Callback(hObject, eventdata, handles)
% hObject handle to popupmenu1 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
val=get(hObject,'Value')
str=get(hObject,'String');
switch str{val}
case 'peaks'
handles.current_data=handles.peaks;
case 'membrane'
handles.current_data=handles.membrane;
case 'sinc'
handles.current_data=handles.sinc;
end
guidata(hObject,handles)
% Hints: contents = get(hObject,'String') returns popupmenu1 contents as cell array % contents{get(hObject,'Value')} returns selected item from popupmenu1
为Mesh按钮编写的响应函数代码如下。

% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
% hObject handle to pushbutton1 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
mesh(handles.current_data)
为Surf按钮编写的响应函数代码如下。

% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject, eventdata, handles)
% hObject handle to pushbutton2 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
surf(handles.current_data)
为Contour3按钮编写的响应函数代码如下。

% --- Executes on button press in pushbutton3.
function pushbutton3_Callback(hObject, eventdata, handles)
% hObject handle to pushbutton3 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
contour3(handles.current_data)
可以看出，每个控件对象都有一个由function语句引导的函数，用户可以在相应的函数
下添加程序代码来完成指定的任务。

在运行图形用户界面文件时，如果单击其中的某个对象，
则在MATLAB机制下自动调用该函数。

课后习题
1．GUIDE中常用的控件有哪些？各有什么作用？
2．设计一个下拉式菜单。

一级菜单有File和Edit两个选项。

File的子菜单为New、Open、。