在弹出菜单中打印出变量

Question

我想在Matlab的弹出菜单中打印出一些变量。弹出菜单首先显示为空，关闭并重新打开菜单后，变量显示出来。如何更改它以在第一个开头显示它。

Answer 1

假设您的菜单定义为Pop=uicontrol('style','popupmenu','string',' ');

然后代码中的任何地方，Pop都可以访问，您可以使用其中一行：

%// assign only 2 number to the Pop menu
set(Pop, 'string', {num2str(val1); num2str(val2)});

%// assign only 2 numbers with labels to the Pop menu     
set(Pop, 'string', {...
        ['Val1 = ' num2str(val1)]; ...
        ['Val2 = ' num2str(val2)]});

或者您可以通过以下方式使其更具可读性和灵活性：

Pop_string = get(Pop, 'string');     %// Read actual String in Pop
Pop_string{3} = ['Val3 = ', Val3];   %// Update 3rd element
set(Pop, 'String', Pop_string);      %// Update the String in Pop

修改

我使用匿名函数制作了示例代码，详见此处：Access nested functions from GUI：

function[]=activePop()
close all,clc
fig=figure;
Pop=uicontrol('style','popupmenu','string',' ');
uicontrol('style','pushbutton','string','Reset',...
  'callback',@(s,a)PushReset(),'position',[5 1 1 1].*get(Pop,'position'));
uicontrol('style','pushbutton','string','Update',...
  'callback',@(s,a)PushUpdate(),'position',[10 1 1 1].*get(Pop,'position'));

  function PushReset()      %// Resets the Pop's list
    N=ceil(5*rand(1));    %// The menu will have 1 to 5 entries
    Labels=cell(N,1);

    for ii=1:N
        Labels{ii}=['Val' num2str(ii) ' = ' num2str(rand)];  %// assign 'Val(ii) = ' label and random value to the list
    end

    set(Pop,'string',Labels)   %// display the list in Pop's menu
  end

  function PushUpdate()   %// Change one (randomly selected) value in Pop's menu
    PopString=get(Pop,'string');   %// get actual List of entries
    N=size(PopString,1);           %// find it's size
    ii=ceil(N*rand);               %// pick one random element
    Line=PopString{ii};            %// read the chosen line
    Line=regexp(Line,' ','split'); %// extract the label
    Line=[Line{1},' ',Line{2},' ',num2str(rand)]; %// update the line
    PopString{ii}=Line;            %// update the line
    set(Pop,'string',PopString);   %// send updated list to the Pop menu
  end

end