Question

我尝试让CardLayout使用按钮更改面板内容（针对不同类中的内容），但由于某种原因，按钮（添加新项目）在点击时不会执行任何操作。< / p>

“添加新项目”按钮的事件侦听器正在尝试访问其他类（NewProject类）

    ...
//CardLayout variables
private JPanel cardPanel;
private static final String CARD_PROJECTTAB = "Card Project Tab";
private static final String CARD_NEWPROJECT = "Card Add Project";
private NewProject newProject;
//private TabPanel tp = new TabPanel();

//

public ProTab(){

//Create cardPanel the panel that holds all the cards.
cardPanel = new JPanel();
cardPanel.setLayout(new CardLayout(0,3));       

//Creating the proPanel that holds all other panels (below cardPanel)
proPanel = new JPanel();
proPanel.setBackground(new Color(204, 255, 102));


/*
  ==========================
  CardLayout Class Instances
  ==========================
*/

cardPanel.add(proPanel, CARD_PROJECTTAB);
newProject = new NewProject();
cardPanel.add(newProject, CARD_NEWPROJECT);

//Creating the contentPane that holds all GUI components and
//uses vertical/horizontal sidebars as needed
contentPane = new JPanel();
contentPane.setBackground(Color.WHITE);

//Giving the contentPane the GridBagLayout
contentPane.setLayout(new GridBagLayout());
GridBagConstraints g = new GridBagConstraints();
g.insets = new Insets(20,0,0,0);

...

//Project bottom buttons START

 bButtonsPanel = new JPanel();
 bButtonsPanel.setBackground(Color.WHITE);
 bButtonsPanel.setBorder(BorderFactory.createMatteBorder(0,0,0,0, Color.gray));
 bButtonsPanel.setLayout(new FlowLayout());
    g.anchor = GridBagConstraints.PAGE_END;
    g.gridx = 0;
    g.gridy = 2;
    contentPane.add(bButtonsPanel, g);

viewProjectButton = new JButton("View Selected Project");
addProjectButton = new JButton ("Add a New Project");

bButtonsPanel.add(viewProjectButton);
bButtonsPanel.add(addProjectButton);

addProjectButton.addActionListener(new buttonListener());

//Project bottom buttons END

}

//Project bottom buttons ActionListeners
private class buttonListener implements ActionListener{
    public void actionPerformed(ActionEvent ae){
        if (ae.getSource() == addProjectButton){
        CardLayout cl = (CardLayout) cardPanel.getLayout();
        cl.show(cardPanel, CARD_NEWPROJECT);
        }
    }
 }

Answer 1

我明白了。我的错误不在于CardLayout的实现，但是我无法从另一个c中正确地调用包含CardLayout的JPanel

之前// getProTab（）是一个返回带有Project Tab元素的JPanel的方法。

    pt = new ProTab();
    tabPane.addTab("Projects", pt.getProTab());
    tabPane.setBackgroundAt(2, (new Color(204, 255, 102)));

之后// getCardPanel（）是一个新方法，我返回包含所有卡片的JPanel（包括// proPanel面板）

    pt = new ProTab();
    tabPane.addTab("Projects", pt.getCardPanel());
    tabPane.setBackgroundAt(2, (new Color(204, 255, 102)));

我无法通过按钮让我的CardLayout切换卡片

1 个答案: