Java-GUI界面编译成功但什么都不显示

Question

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.border.TitledBorder;
import javax.swing.border.Border;

class MyFrame extends JPanel implements ActionListener
{
		JFrame  jfrm= new JFrame();
	 public void actionPerformed(ActionEvent e)
	 {
	 	}

		MyFrame() {
			//Set the panel and choosing area

			JPanel jpan1 = new JPanel();
			jpan1.setBorder(BorderFactory.createTitledBorder("Date of Birth"));

			JPanel jpan2 = new JPanel();
			jpan2.setBorder(BorderFactory.createTitledBorder("Date of Birth"));

			JPanel jpan3 = new JPanel();
			jpan3.setBorder(BorderFactory.createTitledBorder("Programme"));

			JPanel jpan4 = new JPanel();
			jpan4.setBorder(BorderFactory.createTitledBorder("Email"));

			JPanel jpan5 = new JPanel();
			jpan5.setBorder(BorderFactory.createTitledBorder("Phone number"));

			JPanel jpan6 = new JPanel();
			jpan6.setBorder(BorderFactory.createTitledBorder("Booking reference code"));

			JPanel jpan7 = new JPanel();
			JPanel jpan8 = new JPanel();
			JPanel jpanName1 = new JPanel();
			jpanName1.setBorder(BorderFactory.createTitledBorder("First Name"));

			JPanel jpanName2 = new JPanel();
			jpanName2.setBorder(BorderFactory.createTitledBorder("Surname"));

			JPanel jpanMonth = new JPanel();
			jpanMonth.setBorder(BorderFactory.createTitledBorder("Month"));

			JPanel jpanYear = new JPanel();
			jpanYear.setBorder(BorderFactory.createTitledBorder("Year"));

			JButton bt1 = new JButton("Next step");
			JButton bt2 = new JButton("Clear");
			JButton bt3 = new JButton("Exit");
			JTextField JTextFirst = new JTextField();
			JTextField JTextSur = new JTextField();
			JTextField JTextEmail = new JTextField();
			JTextField JTextNumber = new JTextField();
			JTextField JTextCode = new JTextField();
			JCheckBox Box1 = new JCheckBox("I have red and agree to the terms and conditions");
			JCheckBox Box2 = new JCheckBox("I confirm that the information provided is correct");


//Set the Year/Month in JComboBox

			String[] arr1 = new String[8];
			for (int i = 0; i < 8; i++) {
				arr1[i] = String.valueOf(i + 1998);
			}
			String[] arr2 = new String[12];
			for (int i = 0; i < 12; i++) {
				arr2[i] = String.valueOf(i + 1);
			}

			JComboBox Month = new JComboBox(arr2);
			JComboBox BirthYear = new JComboBox(arr1);

//Set the major and year

			String[] arrMajor = new String[2];
			arrMajor[0] = "Telecommunications Engineering with Management";
			arrMajor[1] = "Other Majors";
			String[] arrYear = new String[4];
			for (int i = 0; i < 4; i++) {
			arrYear[i] = String.valueOf(i + 1);
			}
			JComboBox Major = new JComboBox(arrMajor);
			JComboBox stuYear = new JComboBox(arrYear);


			jpan1.add(jpanName1);
			jpan1.add(jpanName2);
			jpanName1.add(JTextFirst);
			jpanName2.add(JTextSur);

			jpan2.add(jpanMonth);
			jpan2.add(jpanYear);
			jpanMonth.add(Month);
			jpanYear.add(BirthYear);

			jpan3.add(Major);
			jpan3.add(stuYear);

			jpan4.add(JTextEmail);

			jpan5.add(JTextNumber);

			jpan6.add(JTextCode);

			jpan7.add(Box1);
			jpan7.add(Box2);

			jpan8.add(bt1);
			jpan8.add(bt2);
			jpan8.add(bt3);
		


		}

}


public class CheckIn extends JFrame{

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		MyFrame jfrm = new MyFrame();
		jfrm.setLayout(new GridLayout(1,9));
		jfrm.setVisible(true);
	}

}

Answer 1

帮你修改了一下代码，但还有很多问题，可以显示了：

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

class MyFrame extends JFrame implements ActionListener {

	public void actionPerformed(ActionEvent e) {
	}

	public MyFrame() {
		setLayout(new GridLayout(1, 9));
		JPanel jpan1 = new JPanel();
		jpan1.setBorder(BorderFactory.createTitledBorder("Date of Birth"));

		JPanel jpan2 = new JPanel();
		jpan2.setBorder(BorderFactory.createTitledBorder("Date of Birth"));

		JPanel jpan3 = new JPanel();
		jpan3.setBorder(BorderFactory.createTitledBorder("Programme"));

		JPanel jpan4 = new JPanel();
		jpan4.setBorder(BorderFactory.createTitledBorder("Email"));

		JPanel jpan5 = new JPanel();
		jpan5.setBorder(BorderFactory.createTitledBorder("Phone number"));

		JPanel jpan6 = new JPanel();
		jpan6.setBorder(BorderFactory.createTitledBorder("Booking reference code"));

		JPanel jpan7 = new JPanel();
		JPanel jpan8 = new JPanel();
		JPanel jpanName1 = new JPanel();
		jpanName1.setBorder(BorderFactory.createTitledBorder("First Name"));

		JPanel jpanName2 = new JPanel();
		jpanName2.setBorder(BorderFactory.createTitledBorder("Surname"));

		JPanel jpanMonth = new JPanel();
		jpanMonth.setBorder(BorderFactory.createTitledBorder("Month"));

		JPanel jpanYear = new JPanel();
		jpanYear.setBorder(BorderFactory.createTitledBorder("Year"));

		JButton bt1 = new JButton("Next step");
		JButton bt2 = new JButton("Clear");
		JButton bt3 = new JButton("Exit");
		JTextField JTextFirst = new JTextField();
		JTextField JTextSur = new JTextField();
		JTextField JTextEmail = new JTextField();
		JTextField JTextNumber = new JTextField();
		JTextField JTextCode = new JTextField();
		JCheckBox Box1 = new JCheckBox("I have red and agree to the terms and conditions");
		JCheckBox Box2 = new JCheckBox("I confirm that the information provided is correct");

//Set the Year/Month in JComboBox

		String[] arr1 = new String[8];
		for (int i = 0; i < 8; i++) {
			arr1[i] = String.valueOf(i + 1998);
		}
		String[] arr2 = new String[12];
		for (int i = 0; i < 12; i++) {
			arr2[i] = String.valueOf(i + 1);
		}

		JComboBox Month = new JComboBox(arr2);
		JComboBox BirthYear = new JComboBox(arr1);


		String[] arrMajor = new String[2];
		arrMajor[0] = "Telecommunications Engineering with Management";
		arrMajor[1] = "Other Majors";
		String[] arrYear = new String[4];
		for (int i = 0; i < 4; i++) {
			arrYear[i] = String.valueOf(i + 1);
		}
		JComboBox Major = new JComboBox(arrMajor);
		JComboBox stuYear = new JComboBox(arrYear);

		jpan1.add(jpanName1);
		jpan1.add(jpanName2);
		jpanName1.add(JTextFirst);
		jpanName2.add(JTextSur);

		jpan2.add(jpanMonth);
		jpan2.add(jpanYear);
		jpanMonth.add(Month);
		jpanYear.add(BirthYear);

		jpan3.add(Major);
		jpan3.add(stuYear);

		jpan4.add(JTextEmail);

		jpan5.add(JTextNumber);

		jpan6.add(JTextCode);

		jpan7.add(Box1);
		jpan7.add(Box2);

		jpan8.add(bt1);
		jpan8.add(bt2);
		jpan8.add(bt3);
		add(jpan1);
		add(jpan2);
		add(jpan3);
		add(jpan4);
		add(jpan5);
		add(jpan6);
		add(jpan7);
		add(jpan8);
		
		setSize(500,500);
		setVisible(true);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setLocationRelativeTo(null);

	}


	public static void main(String[] args) {
		new MyFrame();
	}

}