Java Swing GUI按钮和文本字段不会出现。这是一个包含Jbutton和JTextField的测试代码

Question

this is the main class.button first don't show up first but when you hover the the mouse over the position of button it shows up. but this is not the case with the textfield which is not showing up in any case.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Test {
    public static void main(String[] args){

        JFrame f=new JFrame("Calculator");
        f.setSize(450,450);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);
        JPanel p=new JPanel();
        f.add(p);

        JTextField t=new JTextField(20);
        t.setBounds(5, 5, 0, 0);
        t.setLayout(null);
        p.add(t);

        JButton clear=new JButton("C");        
        clear.setBounds(5,100,50,50);
        clear.setSize(50,40);
        p.add(clear); 

    }
}

Answer 1

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Test {
    public static void main(String[] args){

        JFrame f=new JFrame("Calculator");
        f.setSize(450,450);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel p=new JPanel();
        f.add(p);

        JTextField t=new JTextField(20);
        t.setBounds(5, 5, 0, 0);
        t.setLayout(null);
        p.add(t);

        JButton clear=new JButton("C");        
        clear.setBounds(5,100,50,50);
        clear.setSize(50,40);
        p.add(clear); 
        f.setVisible(true);

    }
}

Try this (use f.setVisible(true) last).

Answer 2

Try enlarging the program window once you run the program. The button and text field should appear then.