SWING：使用 setBackground Container 调用方法会由于递归调用导致 StackOverFlow 错误

Question

当我调用创建 Jpanel 对象和 GridBagLayout 对象并将 JFrame 的背景设置为青色的方法时。我收到一个 Whosebug 错误，我相信这是由于 setBackground 函数试图设置面板背景以外的容器的背景，例如我的按钮，这就是导致错误的原因，我试图将函数放入另一个 JPanel 但没有 avial。我的问题是，我可以在我的代码中做些什么来修复 Whosebug 错误的发生，我是否需要为背景创建一个新面板。

代码：

挥杆方法：

public JFrame frame(){
        JFrame frame = new JFrame();
        frame.setTitle("a new " + MethodHandles.lookup().lookupClass().getName() + " Appears! ");
        return frame;
    }
    public JPanel mainPanel(){
        JPanel mainPanel = new JPanel();
        mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));
        //mainPanel().setBackground(Color.cyan);
        return mainPanel;
    }
    public JPanel panel(){
        JPanel panel = new JPanel(new GridBagLayout());
        panel().setBackground(Color.cyan);
        return panel;
    }
    public GridBagConstraints constr(){
        GridBagConstraints constr = new GridBagConstraints();
        return constr;
    }

class 方法被调用到：

static void AddWindow(){
       Options OPT = new Options();
       Tutors TRS = new Tutors();


       /*JFrame frame = new JFrame();
       frame.setTitle("a new " + MethodHandles.lookup().lookupClass().getName() + " Appears! ");
       JPanel mainPanel = new JPanel();
       mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));*/

      // JPanel panel = new JPanel(new GridBagLayout());
       //panel.setBackground(Color.cyan);

       OPT.frame();
       OPT.mainPanel();
       OPT.panel();
       OPT.constr();

// Constraints for the layout
       //GridBagConstraints constr = new GridBagConstraints();
// Setting initial grid values to 0,0

/////////// first columns ///////////////////////
       OPT.constr().weightx = 0.5;
       OPT.constr().weighty = 0.5;

       OPT.constr().gridx = 0;
       OPT.constr().gridy = 0;
       OPT.panel().add(OPT.NamesText(), OPT.constr());

       OPT.constr().gridx = 0;
       OPT.constr().gridy = 1;
       OPT.panel().add(OPT.ModuleNameText(), OPT.constr());

       OPT.constr().gridx = 0;
       OPT.constr().gridy = 2;
       OPT.panel().add(OPT.PostitionText(), OPT.constr());

       OPT.constr().gridx = 0;
       OPT.constr().gridy = 3;
       OPT.panel().add(OPT.AreaOfExpertiseText(), OPT.constr());

       OPT.constr().gridx = 0;
       OPT.constr().gridy = 4;
       OPT.panel().add(OPT.StudentsSupervisedText(), OPT.constr());


/////////// second column ////////////////////
       OPT.constr().gridx = 1;
       OPT.constr().gridy = 0;
       OPT.panel().add(OPT.Names(), OPT.constr());

       OPT.constr().gridx = 1;
       OPT.constr().gridy = 1;
       OPT.panel().add(OPT.ModuleName(), OPT.constr());

       OPT.constr().gridx = 1;
       OPT.constr().gridy = 2;
       OPT.panel().add(OPT.Position(), OPT.constr());

       OPT.constr().gridx = 1;
       OPT.constr().gridy = 3;
       OPT.panel().add(OPT.AreaOfExperise(), OPT.constr());

       OPT.constr().gridx = 1;
       OPT.constr().gridy = 4;
       OPT.panel().add(OPT.StudentsSupervised(), OPT.constr());

       OPT.constr().gridx = 1;
       OPT.constr().gridy = 5;
       OPT.panel().add(OPT.SubmitButton(), OPT.constr());



       OPT.mainPanel().add(OPT.panel());
       OPT.frame().add(OPT.mainPanel());

       OPT.frame().pack();
       OPT.frame().setSize(800,800);
       OPT.frame().setLocationRelativeTo(null);
       OPT.frame().setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       OPT.frame().setVisible(true);

   }

Answer 1

每次调用此方法时，它都会自行调用直到崩溃...

public JPanel panel(){
    JPanel panel = new JPanel(new GridBagLayout());
    panel().setBackground(Color.cyan);
    return panel;
}

现在可能是考虑将这些方法重命名为类似 getXxx

的好时机

Thanks , thats worked :) , now that the frame runs it is completely empty, however when i created all the objects inside the class it worked fine, is there a chance that calling the methods from outside the class is breaking the code due to the objects not being created in the same class ?

每次您调用其中一种方法时，都会创建该对象的一个新实例。

这个...

OPT.getFrame().pack();
OPT.getFrame().setSize(800, 800);
OPT.getFrame().setLocationRelativeTo(null);
OPT.getFrame().setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
OPT.getFrame().setVisible(true);

单独创建了 5 个单独的 JFrame 实例，其中没有一个与之前的

有任何关系

相反，您应该考虑重新设计解决方案以隔离功能或使用“惰性”属性，例如...

public class Options {

    private JFrame frame;
    private JPanel mainPanel;
    private JPanel panel;
    private GridBagConstraints gbc;

    public JFrame getFrame() {
        if (frame == null) {
            frame = new JFrame();
            frame.setTitle("a new " + MethodHandles.lookup().lookupClass().getName() + " Appears! ");
        }
        return frame;
    }

    public JPanel getMainPanel() {
        if (mainPanel == null) {
            mainPanel = new JPanel();
            mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));
            //mainPanel().setBackground(Color.cyan);
        }
        return mainPanel;
    }

    public JPanel getPanel() {
        if (panel == null) {
            panel = new JPanel(new GridBagLayout());
            panel.setBackground(Color.cyan);
        }
        return panel;
    }

    public GridBagConstraints getGridBagConstraints() {
        if (gbc == null) {
            gbc = new GridBagConstraints();
        }            
        return gbc;
    }
}

SWING：使用 setBackground Container 调用方法会由于递归调用导致 StackOverFlow 错误

SWING : calling a method with the setBackground Container causes StackOverFlow error due to recursive call

java

swing

jframe