Java动态显示JLabel

Question

I have a button. If I click this button, a popup appears. The popup asking me to write a word. if I write a word 6 letter, 6 jlabels appear, but if I enter another word shorter, the JLabels do not disappear

I want my JLabels may decrease according to a shorter word, but i don't know :(

thx for your great help !

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    //BUTTON 1 WORD
    Controller c = new Controller();
    try {
        final JFrame popup = new JFrame();

        //display popup
        word = JOptionPane.showInputDialog(popup, "Enter one word", null);
        //control the length of the word
        c.controleW(word);

        //display jlabel lenght of word
        keyNumber.setText(String.valueOf(word.length()));


        //JLabels displays depending on the word length
        int pixels = 50;
        for (int i = 0; i < word.length(); i++) {
            label = new JLabel("_");
            label.setBounds(pixels, 200, 30, 30);
            add(label);
            label.repaint();
            pixels += 20;
        }

    } catch (Exception e) {
        System.out.println(e);
    }

}  

And my class to control the length of the word

public String controleW(String word) {
    boolean flag = false;
    final JFrame popup = new JFrame();

    while (flag == false) {
        if (word.length() <= 3) {
            word = JOptionPane.showInputDialog(popup, "Enter one word", null);
        } else {
            flag = true;
        }
    };
    return null;
}

Answer 1

You are always adding labels in your method, never removing any, thus running the code twice will indeed add labels twice. To fix it, you can simply add a removeAll(); in jButton1ActionPerformed before you add any labels. This makes sure that any previously added components will be removed.