在对象之间交换属性值

发布于 2024-11-19 23:46:44 字数 214 浏览 3 评论 0 原文

我通过图中的注释（.）创建了两个文本框。它们的大部分属性已经被定义；回调函数可以在窗口中进行拖放操作。我为盒子创建了一个 uicontextmenu。右键单击可以选择功能列表以进行后续操作。

我尝试添加的操作之一涉及在两个框之间交换字符串。我需要获取当前右键单击的框中的字符串，该字符串应与我随后左键单击的框中的字符串交换。我可以获得有关如何扩展 uimenu 功能以便它注册后续左键单击的建议吗？

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土豪 2024-11-26 23:46:44

您将需要手动存储最后单击的框。如果您使用 GUIDE 来设计 GUI，请使用传递给回调函数的 handles 结构。否则，如果您以编程方式生成组件，则嵌套回调函数可以访问其封闭函数内定义的变量。

编辑

这是一个完整的示例：右键单击并从上下文菜单中选择“交换”，然后选择另一个文本框来交换字符串（左键单击）。请注意，我必须禁用/启用两个步骤之间的文本框才能触发 ButtonDownFcn （请参阅此页面进行解释)

function myTestGUI
    %# create GUI
    hLastBox = [];          %# handle to textbox initiating swap
    isFirstTime = true;     %# show message box only once
    h(1) = uicontrol('style','edit', 'string','1', 'position',[100 200 60 20]);
    h(2) = uicontrol('style','edit', 'string','2', 'position',[400 200 60 20]);
    h(3) = uicontrol('style','edit', 'string','3', 'position',[250 300 60 20]);
    h(4) = uicontrol('style','edit', 'string','4', 'position',[250 100 60 20]);

    %# create context menu and attach to textboxes
    hCMenu = uicontextmenu;
    uimenu(hCMenu, 'Label','Swap String...', 'Callback', @swapBeginCallback);
    set(h, 'uicontextmenu',hCMenu)

    function swapBeginCallback(hObj,ev)
        %# save the handle of the textbox we right clicked on
        hLastBox = gco;

        %# we must disable textboxes to be able to fire the ButtonDownFcn
        set(h, 'ButtonDownFcn',@swapEndCallback)
        set(h, 'Enable','off')

        %# show instruction to user
        if isFirstTime
            isFirstTime = false;
            msgbox('Now select textbox you want to switch string with');
        end
    end
    function swapEndCallback(hObj,ev)
        %# re-enable textboxes, and reset ButtonDownFcn handler
        set(h, 'Enable','on')
        set(h, 'ButtonDownFcn',[])

        %# swap strings
        str = get(gcbo,'String');
        set(gcbo, 'String',get(hLastBox,'String'))
        set(hLastBox, 'String',str)
    end
end

You will need to manually store the last clicked box. If you are using GUIDE to design your GUI, use the handles structure which gets passed around to callback functions. Otherwise if you programmatically generate the components, then nested callback functions have access to variables defined inside their enclosing functions.

EDIT

Here is a complete example: right-click and select "Swap" from context menu, then choose the other textbox to swap strings with (left-click). Note that I had to disable/enable the textboxes in-between the two steps to be able to fire the ButtonDownFcn (see this page for an explanation)

function myTestGUI
    %# create GUI
    hLastBox = [];          %# handle to textbox initiating swap
    isFirstTime = true;     %# show message box only once
    h(1) = uicontrol('style','edit', 'string','1', 'position',[100 200 60 20]);
    h(2) = uicontrol('style','edit', 'string','2', 'position',[400 200 60 20]);
    h(3) = uicontrol('style','edit', 'string','3', 'position',[250 300 60 20]);
    h(4) = uicontrol('style','edit', 'string','4', 'position',[250 100 60 20]);

    %# create context menu and attach to textboxes
    hCMenu = uicontextmenu;
    uimenu(hCMenu, 'Label','Swap String...', 'Callback', @swapBeginCallback);
    set(h, 'uicontextmenu',hCMenu)

    function swapBeginCallback(hObj,ev)
        %# save the handle of the textbox we right clicked on
        hLastBox = gco;

        %# we must disable textboxes to be able to fire the ButtonDownFcn
        set(h, 'ButtonDownFcn',@swapEndCallback)
        set(h, 'Enable','off')

        %# show instruction to user
        if isFirstTime
            isFirstTime = false;
            msgbox('Now select textbox you want to switch string with');
        end
    end
    function swapEndCallback(hObj,ev)
        %# re-enable textboxes, and reset ButtonDownFcn handler
        set(h, 'Enable','on')
        set(h, 'ButtonDownFcn',[])

        %# swap strings
        str = get(gcbo,'String');
        set(gcbo, 'String',get(hLastBox,'String'))
        set(hLastBox, 'String',str)
    end
end

screenshot