如何在JPanel类中使用GridBagConstraints

Question

我试图在扩展JPanel的类中使用griddbagconstraints，但之后将代码如下:

    import java.awt.Insets;
    import java.awt.Toolkit;
    import javax.swing.JLabel;
    import javax.swing.JPanel;
    public class RightPanel extends JPanel {
private static final long serialVersionUID = 2L;
JLabel start;
JLabel first;
GridBagConstraints c;
public RightPanel() {
    setVisible(true);
    c = new GridBagConstraints();
    c.insets = new Insets(10 ,10, 10, 10);
    start = new JLabel("Start");
    start.setFont(new Font("comic sans ms", Font.PLAIN, 20));
    start.setForeground (new Color(111,0,0));
    c.gridx = 0;
    c.gridy = 5;
    add(start, c);
    first = new JLabel("About");
    first.setFont(new Font("comic sans ms", Font.PLAIN, 20));
    first.setForeground (new Color(111,0,0));
    c.gridx = 0;
    c.gridy = 5;
    add(first ,c);
}
public void paint(Graphics g) {
    Image a = Toolkit.getDefaultToolkit().getImage("C:\Users\Favour's Computer\workspace\Physics Calculator\src\res\rightside.PNG");
    g.drawImage(a, 0, 0, getSize().width, getSize().height, this);
    super.paint(g);
}
    }

现在的问题是在哪里添加声明代码在jpanel构造器即RightPanel rp = new RightPanel(new GridBagLayout());，但新的GridBagLayout()不工作，请帮助

Answer 1

RightPanel rp = new RightPanel(new GridBagLayout());

上面的代码将不起作用，因为你的构造函数中没有任何参数。

public class RightPanel extends JPanel
//codes...
public RightPanel() //You don't have any parameter in your constructor

如果你想设置你的类的布局使用

setLayout(new GridBagLayout())