Question

下午好！

我目前正在尝试使用App Designer使用MATLAB构建应用程序。我们的目标是能够使用多个GPX文件绘制数据，而我已经成功地完成了这些工作。我很好奇我应该如何填充列表框。

是否有一种方法使Listbox填充文件名，具体取决于您选择的文件夹？

Answer 1

您可以使用dir列出文件夹的内容，将名称列表转换为单元格数组，并使用单元格数组填充ListBox Items。

假设您有一个带有ButtonButtonPushed回调的Button，并且希望让用户选择一个文件夹，然后在列表框中填充所有* .gpx文件。

您可以按照以下步骤进行操作：

% Button button pushed function
function ButtonButtonPushed(app)
    selpath = uigetdir(); %Open dialog box for selecting folder.
    gpx_files = dir(fullfile(selpath, '*.gpx')); %Dir all *.gpx in selected folder.
    %Populate listbox with file names:
    app.ListBox.Items = {gpx_files(:).name};
end

语句app.ListBox.Items = {gpx_files(:).name};填充列表框。

gpx_files(:).name是文件名列表。
{gpx_files(:).name}从列表中创建一个单元格数组。
app.ListBox.Items = {gpx_files(:).name};使用创建的单元格数组设置ListBox的Items属性。

获取所选文件的完整路径：

保留所选文件夹：
添加一个名为selpath的私有属性（使用设计器[代码视图]中的红色P +添加新属性，然后编辑该属性的名称）：
```
properties (Access = private)
    selpath % Store selected path
end
```

在按下按钮时将所选路径存储在selpath属性中：

% Button pushed function: Button
function ButtonButtonPushed(app, event)
    app.selpath = uigetdir(); %Open dialog box for selecting folder.
    gpx_files = dir(fullfile(app.selpath, '*.gpx')); %Dir all *.gpx in selected folder.

    %Populate listbox with file names:
    app.ListBox.Items = {gpx_files(:).name};
end

现在，所选路径存储在app.selpath中。

添加“ ListBoxChangeValue”回调（在设计视图中右键单击列表框）。
编辑ListBoxValueChanged函数的代码：
返回的value value = app.ListBox.Value;是所选文件的名称（您无需使用strcmpi）。
使用fullfile函数将路径与文件名连接起来。
```
% Value changed function: ListBox
function ListBoxValueChanged(app, event)
    value = app.ListBox.Value;
    selected_file = fullfile(app.selpath, value); %Get the full path of selected file.
    disp(selected_file) %Change the code to load selected_file
end
```
上面的代码在命令窗口中显示selected_file字符串。
将disp(selected_file)替换为您自己的代码（加载并绘制gpx文件）。

这是App1的完整代码（大多数代码是自动生成的）：

classdef App1 < matlab.apps.AppBase

    % Properties that correspond to app components
    properties (Access = public)
        UIFigure      matlab.ui.Figure
        Button        matlab.ui.control.Button
        LabelListBox  matlab.ui.control.Label
        ListBox       matlab.ui.control.ListBox
    end


    properties (Access = private)
        selpath % Store selected path
    end


    % Callbacks that handle component events
    methods (Access = private)

        % Code that executes after component creation
        function startupFcn(app)

        end

        % Button pushed function: Button
        function ButtonButtonPushed(app, event)
            app.selpath = uigetdir(); %Open dialog box for selecting folder.
            gpx_files = dir(fullfile(app.selpath, '*.gpx')); %Dir all *.gpx in selected folder.

            %Populate listbox with file names:
            app.ListBox.Items = {gpx_files(:).name};
        end

        % Value changed function: ListBox
        function ListBoxValueChanged(app, event)
            value = app.ListBox.Value;
            selected_file = fullfile(app.selpath, value); %Get the full path of selected file.
            disp(selected_file) %Change the code to load selected_file
        end
    end

    % Component initialization
    methods (Access = private)

        % Create UIFigure and components
        function createComponents(app)

            % Create UIFigure and hide until all components are created
            app.UIFigure = uifigure('Visible', 'off');
            app.UIFigure.Position = [101 101 640 480];
            app.UIFigure.Name = 'UI Figure';

            % Create Button
            app.Button = uibutton(app.UIFigure, 'push');
            app.Button.ButtonPushedFcn = createCallbackFcn(app, @ButtonButtonPushed, true);
            app.Button.Position = [43 380 114 49];
            app.Button.Text = 'Select Folder';

            % Create LabelListBox
            app.LabelListBox = uilabel(app.UIFigure);
            app.LabelListBox.HorizontalAlignment = 'right';
            app.LabelListBox.VerticalAlignment = 'top';
            app.LabelListBox.Position = [300 412 44 15];
            app.LabelListBox.Text = 'List Box';

            % Create ListBox
            app.ListBox = uilistbox(app.UIFigure);
            app.ListBox.ValueChangedFcn = createCallbackFcn(app, @ListBoxValueChanged, true);
            app.ListBox.Position = [359 355 100 74];

            % Show the figure after all components are created
            app.UIFigure.Visible = 'on';
        end
    end

    % App creation and deletion
    methods (Access = public)

        % Construct app
        function app = App1

            % Create UIFigure and components
            createComponents(app)

            % Register the app with App Designer
            registerApp(app, app.UIFigure)

            % Execute the startup function
            runStartupFcn(app, @startupFcn)

            if nargout == 0
                clear app
            end
        end

        % Code that executes before app deletion
        function delete(app)

            % Delete UIFigure when app is deleted
            delete(app.UIFigure)
        end
    end
end

MATLAB AppDesigner列表框

1 个答案: