java从组件中解析数据

Question

我正在创建一个游戏，我正在做一个角色选择屏幕，其中有一个用于输入用户名的 JTextField，该屏幕还有一个 JButton“创建角色”，按下该按钮时将解析 JTextField 以及是否有任何问题(名称中的空格、以空格开头等。)它会将一些文本放入 JTextField 旁边的 JLabel 中。

我将 JButton 连接到一个 actionPerformed 方法，该方法调用一个解析数据的函数。我的问题是，每次按下按钮时，都会在原始 JLabel 之上放置一个新标签。

我像这样创建 JLabel:

public static JLabel label;
label = new JLabel();
// some properties

我这样调用解析方法:

parseCharacterSelection(nameInput, label);

其中 nameInput 是 JTextField。 我的问题是，为什么每次按下 JButton 时都会创建一个新标签

public void parseCharacterCreation(JTextField input, JLabel label) {

    // Variable that hold whether or not
    // the User Name is acceptable

    player_name = input.getText();

    // Make some initial checks on the
    // input string
    //----------------------------------
    if( player_name.isEmpty() ) {
        label.setText("You need to pick a username");
    } else if( player_name.startsWith(" ") ) {
        label.setText("Name Cannot start with a space");
    } else {
        pass = true;
    }

    // Attempt to write to file
    // Catch some errors
    //----------------------------------
    if(pass == true) {
        try {
            if( player_name.contains(" ") ) {
                player_name = player_name.replaceAll("\\s", "_");
                player_file = new File("src/Resources/characters/" + player_name + ".properties");
            }

            if(!player_file.exists()) {
                player_file.createNewFile();
            }

            FileWriter      fw = new FileWriter(player_file.getAbsoluteFile());
            BufferedWriter  bw = new BufferedWriter(fw);

            bw.write(player_name);
            bw.close();

        } catch( IOException e ) {
            e.printStackTrace();
        } finally {
            System.out.println("DONE");
        }
    }
}

//屏幕字符类

public class ScreenCharacter extends JPanel {

public static JButton       create;
public static JTextField    nameInput;
public static JLabel        errorLabel;

public ScreenCharacter() {

    this.setLayout(null);
    this.add(createUserName());
    this.add(createMainArea());
}

private static JPanel createUserName() {

    MatteBorder matteBorder = new MatteBorder(1, 0, 1, 0, Color.decode("#222222"));
    EmptyBorder emptyBorder = new EmptyBorder(10, 75, 10, 10);
    CompoundBorder border   = new CompoundBorder(matteBorder, emptyBorder);

    JPanel userNameArea     = new JPanel();
    userNameArea.setLayout(new FlowLayout(FlowLayout.LEFT, 0, 0));
    userNameArea.setBounds(0, 35, Engine.screenX, 50);
    userNameArea.setBorder(border);
    userNameArea.setBackground(new Color(255, 255, 255, 70));

    JLabel nameLabel        = new JLabel();
    nameLabel.setText("Enter Your Username: ");

    nameInput = new JTextField();
    nameInput.setForeground(Color.black);
    nameInput.setBorder(BorderFactory.createEmptyBorder(0, 5, 0, 0));
    nameInput.setPreferredSize(new Dimension(200, 25));

    errorLabel = new JLabel();
    errorLabel.setText("This is a test label");
    errorLabel.setBorder(BorderFactory.createEmptyBorder(0, 20, 0, 0));
    errorLabel.setPreferredSize(new Dimension(200, 25));
    errorLabel.setAlignmentX(JLabel.LEFT_ALIGNMENT);

    userNameArea.add(nameLabel);
    userNameArea.add(nameInput);
    userNameArea.add(errorLabel);


    return userNameArea;
}

private static JPanel createMainArea() {

    JPanel resetCreatePanel = new JPanel(new GridLayout(1, 2));
    resetCreatePanel.setPreferredSize(new Dimension(300, 30));
    resetCreatePanel.setBackground(Color.black);

    create  = new JButton("Create Character");
    create.setBorder(BorderFactory.createLineBorder(Color.decode("#171717")));
    create.setFont(new Font("Dialog", 1, 11));
    create.setBackground(Color.black);
    create.setForeground(Color.white);
    create.setFocusPainted(false);
    create.setContentAreaFilled(false);
    create.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent arg0) {
            if(!errorLabel.getText().isEmpty()) {
                errorLabel.setText("");
            } else {
                Engine.p_parser.parseCharacterCreation(nameInput, errorLabel);
            }
        }
    });

    resetCreatePanel.add(create);


}

}

//引擎

public class Engine {
    public static PlayerParser p_parser;
    public Engine() {
        p_parser = new PlayerParser();

    }
}

Answer 1

感谢大家的帮助。 “问题”是组件所在的 JPanel 具有半透明背景。具有透明度的 JComponent 会以某种方式搞乱，这使得它看起来像是正在创建多个标签。但在没有透明度的情况下它也能正常工作。