MATLAB之GUI学习经典举例

桃扇骨 2022-02-23 07:26 160阅读 0赞

### 文章目录 ###

*  1. 设置背景颜色
 *   *  1.1 通过GUI按钮设置背景颜色
     *  1.2 通过GUI运行设置背景颜色
 *  2. 错误对话框
 *   *  2.1 “截屏失败”举例
 *  3. 计算器
 *   *  按钮callback
     *  \+-\*/ callback
     *  = callback
     *  √ callback
     *  ← callback
     *  C callback
 *  4. 退出
 *  5. 选择列表框绘图
 *  6. 取弹出式菜单里的值

# 1. 设置背景颜色 #

## 1.1 通过GUI按钮设置背景颜色 ##

function backswitch_Callback(hObject, eventdata, handles)
    % hObject    handle to backswitch (see GCBO)
    % eventdata  reserved - to be defined in a future version of MATLAB
    % handles    structure with handles and user data (see GUIDATA)
    ha = axes('units','normalized','position',[0 0 1 1]);
    uistack(ha, 'down')
    [fname, pname, index] = uigetfile({
        '*.jpg; *.bmp'},'选择背景图片');  
    if  index
        II = imread([pname,fname]);
        image(II)
        colormap gray
        set(ha,'handlevisibility','off','visible','off');
    else
        errordlg('选择背景失败');       %提示错误对话框
        hDialog = findall(0,'tag','Msgbox_Error Dialog');
        btn_ok = findall(hDialog,'style','pushbutton');
        set(btn_ok,'String','确定');    
    end

## 1.2 通过GUI运行设置背景颜色 ##

% --- Executes just before computesumprice is made visible.
    function computesumprice_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 computesumprice (see VARARGIN)
    
    % Choose default command line output for computesumprice
    ha = axes('units','normalized','position',[0 0 1 1]);
    uistack(ha, 'down') % up，down,可选
    II = imread('1.jpg');
    image(II)
    colormap gray
    set(ha,'handlevisibility','off','visible','off');
    
    handles.output = hObject;
    % Update handles structure
    guidata(hObject, handles);

# 2. 错误对话框 #

## 2.1 “截屏失败”举例 ##

% --- Executes on button press in screencapture.
    function screencapture_Callback(hObject, eventdata, handles)
    % hObject    handle to screencapture (see GCBO)
    % eventdata  reserved - to be defined in a future version of MATLAB
    % handles    structure with handles and user data (see GUIDATA)
    [fname, ~, index] = uiputfile({
        '*.jpg'});  
    if  index
         a = getframe(computesumprice);%注意不是gcf
         imwrite(a.cdata,fname);  
    else
        errordlg('导出失败');       %提示错误对话框
        hDialog = findall(0,'tag','Msgbox_Error Dialog');
        btn_ok = findall(hDialog,'style','pushbutton');
        set(btn_ok,'String','确定');    
    end

# 3. 计算器 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0hlYXJ0X1NlYQ_size_16_color_FFFFFF_t_70]

## 按钮callback ##

str_cur = get(handles.display, 'string');
    str_cur_val = str2double(get(handles.display, 'string'));
    current(1) = get(hObject, 'string'); 
    % 判断初始化是否为0
    if str_cur_val == 0
        set(handles.display,'string',current(1));
    else
        set(handles.display,'string',[str_cur,current(1)]);
    end

## ±\*/ callback ##

str_before = get(handles.display, 'string'); 
    add_str = get(handles.add, 'string'); 
    set(handles.display,'string',[str_before,add_str]);

## = callback ##

equal_sign = get(hObject,'string');%获取=
    str_before = get(handles.display, 'string'); %获取display的字符
    answer = eval(str_before);%MATLAB提供的eval函数，可根据字符直接计算，无需格外编写算法
    set(handles.display,'string',strcat(str_before,equal_sign,num2str(answer)));

## √ callback ##

str_before = get(handles.display, 'string'); 
    square_root_str = 'sqrt'; 
    leftk ='(';
    rightk =')';
    set(handles.display,'string',[square_root_str,leftk ,str_before,rightk]);

## ← callback ##

textString = get(handles.display,'String');
    n=length(textString);
    t=char(textString);
    textString=t(1:n-1);
    set(handles.display,'String',textString)

## C callback ##

set(handles.display , 'string', num2str(0));

# 4. 退出 #

h = gcf;
    close(h);

# 5. 选择列表框绘图 #

seldata = get(handles.seldata, 'value'); %seldata为列表框tag
    axes(handles.axes2)
    
    switch seldata
        case 1
             plot(t,data1)
             title('传声器1时域数据')
        case 2
             plot(t,data2)
             title('传声器2时域数据')   
        otherwise
            return
    end

# 6. 取弹出式菜单里的值 #

winType = get(handles.winType, 'value');
    switch winType
        case 1
            w = hanning(NFFT);
        case 2
            w = boxcar(NFFT);   
        case 3
            w = hamming(NFFT);
        otherwise
            return
    end

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