我做错了什么，第二个按钮起作用很奇怪？

Question

我知道代码很糟糕且容易。我是一个入门者，需要一些帮助。我想在我的代码中添加第二个按钮。我觉得自己更改了按钮的坐标，因此不会“落在第一个”上。有什么建议吗？ （同样，这对我来说有点未知，所以我只是复制 - 粘贴它，希望它不会影响第二个按钮。我觉得这与我输入的按钮的坐标有关）。

import java.awt.*;

import java.awt.event.*;

public class CalculatorGUI extends Frame implements ActionListener

{

static Operand op;
TextField display;
Button button0;
Button button1;
public CalculatorGUI(String title, Operand op)
{               
    super(title);
    CalculatorGUI.op = op;
    this.setLayout(null);
    this.setFont(new Font("TimesRoman", Font.PLAIN, 14));
    this.setBackground(Color.blue);
    button0 = new Button("0");
    button0.setBounds(64, 265, 35, 28);
    button0.setFont(new Font("TimesRoman", Font.PLAIN, 14));
    button0.setForeground(Color.blue);
    button0.setFocusable(false);
    button0.addActionListener(this);
    this.add(button0);
    this.setSize(283,320);
    this.setLocation(40,30);
    this.setVisible(true);
    this.setResizable(false);
    
    button1 = new Button("1");
    button1.setBounds(64, 230, 35, 28);
    button1.setFont(new Font("TimesRoman", Font.PLAIN, 14));
    button1.setForeground(Color.blue);
    button1.setFocusable(false);
    button1.addActionListener(this);
    this.add(button1);
    this.setSize(283,320);
    this.setLocation(40,30);
    this.setVisible(true);
    this.setResizable(false);
    
    this.addWindowListener(new CloseWindowAndExit());
    display = new TextField("");
    display.setEditable(false);
    display.setBounds(13, 55, 257, 30);
    this.add(display);
    
}

class CloseWindowAndExit extends WindowAdapter
{
    public void windowClosing(WindowEvent closeWindowAndExit)
    {
        System.exit(0);
    }
}

@Override
public void actionPerformed(ActionEvent e) 
{
    
    if(e.getSource()==button0) 
    {
      display.setText("Button0 is pressed");
      CalculatorGUI.op.addDigit('0');
    }
}

}

Answer 1

请勿将按钮直接添加到主帧。相反，创建另一个面板并将按钮添加到它：

    Panel newPanel = new Panel(new GridBagLayout());

    Button button0 = new Button("BUTTON_0");
    button0.setBounds(10, 265, 30, 30);
    button0.setFont(new Font("TimesRoman", Font.PLAIN, 14));
    button0.setForeground(Color.blue);
    button0.setFocusable(false);

    Button button1 = new Button("BUTTON_1");
    button1.setBounds(10, 265, 30, 30);
    button1.setFont(new Font("TimesRoman", Font.PLAIN, 14));
    button1.setForeground(Color.blue);
    button1.setFocusable(false);

    newPanel.add(button0);
    newPanel.add(button1);

    this.add(newPanel);