Question

我有一个创造笑脸的课程。当我运行下面的代码时，一切都工作了，创建了9个笑脸对象并显示在网格布局中。但是，我想采用循环9次的代码块并创建/显示9个表情符号，并在单击creatSmiley按钮时调用它。

然而，当我将那段代码移动到actionEvent时，当我运行代码并按下按钮时没有任何反应。

创建对象的笑脸类扩展了jpanel并使用paint方法创建了一个笑脸。

任何提示？

      public class SmileyGrid extends JFrame implements ActionListener
{

private JPanel buttonPanel, panel, facePanel;
private JButton pumpkinButton, smileyButton;



public static void main(String[] args)
{
    SmileyGrid myGrid = new SmileyGrid(); 
    myGrid.setSize(700, 700);
    myGrid.setLayout(new BorderLayout());
    myGrid.createGUI();
    myGrid.setVisible(true);

}

public SmileyGrid()
{

}

private void createGUI()
{
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    Container window = getContentPane();
    window.setLayout (new BorderLayout());

    facePanel = new JPanel();
    facePanel.setLayout(new GridLayout(3,3));
    facePanel.setPreferredSize(new Dimension(700, 700));
    add(facePanel);

    smileyButton = new JButton("Create Smiley");
    pumpkinButton = new JButton("Create Pumpkin");

    smileyButton.addActionListener(this);


    buttonPanel = new JPanel();
    buttonPanel.setBackground(Color.white);
    add (buttonPanel, BorderLayout.SOUTH);

    buttonPanel.add(smileyButton);
    buttonPanel.add(pumpkinButton);


    for(int i=0;i<9;i++)
    {
        Random r = new Random();
        Color color1=new Color(r.nextInt(256),r.nextInt(256),r.nextInt(256));
        Color color2=new Color(r.nextInt(256),r.nextInt(256),r.nextInt(256));
        Color color3=new Color(r.nextInt(256),r.nextInt(256),r.nextInt(256));
        Color color4=new Color(r.nextInt(256),r.nextInt(256),r.nextInt(256));

        Smiley mySmiley = new Smiley(color1, color2, color3, color4);

        facePanel.add(mySmiley);
    }

}
public void actionPerformed(ActionEvent ae)
{  

}
}

Answer 1

所以，我修改了你的基本代码，因为你没有包含Smiley类，将for-loop移到ActionListener＆＃39; s {{ 1}}方法，在我创建了一堆新的＆＃34;虚假的表情符号后，在actionPerformed上调用revalidate和repaint＆＃34;它对我来说效果很好

facePanel

如果您有任何其他问题，那么可能是您的import java.awt.BorderLayout; import java.awt.Color; import java.awt.Container; import java.awt.Dimension; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.Random; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; public class SmileyGrid extends JFrame implements ActionListener { private JPanel buttonPanel, panel, facePanel; private JButton pumpkinButton, smileyButton; public static void main(String[] args) { SmileyGrid myGrid = new SmileyGrid(); myGrid.setSize(700, 700); myGrid.setLayout(new BorderLayout()); myGrid.createGUI(); myGrid.setVisible(true); } public SmileyGrid() { } private void createGUI() { setDefaultCloseOperation(EXIT_ON_CLOSE); Container window = getContentPane(); window.setLayout(new BorderLayout()); facePanel = new JPanel(); facePanel.setLayout(new GridLayout(3, 3)); facePanel.setPreferredSize(new Dimension(700, 700)); add(facePanel); smileyButton = new JButton("Create Smiley"); pumpkinButton = new JButton("Create Pumpkin"); smileyButton.addActionListener(this); buttonPanel = new JPanel(); buttonPanel.setBackground(Color.white); add(buttonPanel, BorderLayout.SOUTH); buttonPanel.add(smileyButton); buttonPanel.add(pumpkinButton); // for (int i = 0; i < 9; i++) { // Random r = new Random(); // Color color1 = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256)); // Color color2 = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256)); // Color color3 = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256)); // Color color4 = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256)); // // Smiley mySmiley = new Smiley(color1, color2, color3, color4); // // facePanel.add(mySmiley); // } } @Override public void actionPerformed(ActionEvent ae) { for (int i = 0; i < 9; i++) { Random r = new Random(); Color color1 = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256)); Color color2 = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256)); Color color3 = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256)); Color color4 = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256)); // Smiley mySmiley = new Smiley(color1, color2, color3, color4); JPanel mySmiley = new JPanel() { @Override public Dimension getPreferredSize() { return new Dimension(20, 20); } }; mySmiley.setBackground(color1); facePanel.add(mySmiley); } facePanel.revalidate(); facePanel.repaint(); } }班级

使用actionListener从单独的类中显示对象

1 个答案: