Java JPanel未出现在JFrame中

我的框架：

public class Interface extends JFrame  {

public void Interface(){    
  PannelDez panel2 = new PannelDez();
  this.add(panel2);
  this.setSize(400, 500);
  this.setVisible(true);
  this.setResizable(false);

  // Menüleiste

  JMenuBar jmb = new JMenuBar();
  this.setJMenuBar(jmb);
  JMenu file = new JMenu("Option");
  jmb.add(file);
  JMenuItem dez = new JMenuItem("Dezimal-Rechner");
  file.add(dez);
  JMenuItem hex = new JMenuItem("Hex-Rechner");
  file.add(hex);
  this.setVisible(true);
}
}

专家组：

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class PannelDez extends JPanel {
    JLabel text = new JLabel();
    JButton delete = new JButton();
    JButton zero = new JButton();
    JButton eins = new JButton();
    JButton zwei = new JButton();
    JButton drei = new JButton();
    JButton vier = new JButton();
    JButton fuenf = new JButton();
    JButton sechs = new JButton();
    JButton sieben = new JButton();
    JButton acht = new JButton();
    JButton neun = new JButton();
    JButton addieren = new JButton();
    JButton subtrahieren = new JButton();
    JButton multiplizieren = new JButton();
    JButton dividieren = new JButton();
    JButton ergebnis = new JButton();
    JTextField anzeige = new JTextField();
    String erg = "";
    int temp1;
    RechnerInt interfaceRechner = new RechnerInt();

    public PannelDez() {

        //Panel

        JPanel panel2 = new JPanel();
        panel2.setSize(400, 500);
        this.setVisible(true);
        anzeige.setBounds(125,100, 200, 50);
        anzeige.setEditable(false);
        anzeige.setBackground(Color.WHITE);
        anzeige.setText(erg);
        this.add(anzeige);


        //Buttons 

        delete.setText("C");
        zero.setText("0");
        eins.setText("1");
        zwei.setText("2");
        drei.setText("3");
        vier.setText("4");
        fuenf.setText("5");
        sechs.setText("6");
        sieben.setText("7");
        acht.setText("8");
        neun.setText("9");
        addieren.setText("+");
        subtrahieren.setText("-");
        multiplizieren.setText("*");
        dividieren.setText("/");
        ergebnis.setText("=");

        delete.setBounds(225, 350, 50, 50);
        zero.setBounds(175, 350,50,50);
        eins.setBounds(125, 300,50,50);
        zwei.setBounds(175, 300,50,50);
        drei.setBounds(225, 300,50,50);
        vier.setBounds(125, 250,50,50);
        fuenf.setBounds(175, 250,50,50);
        sechs.setBounds(225, 250,50,50);
        sieben.setBounds(125, 200,50,50);
        acht.setBounds(175, 200,50,50);
        neun.setBounds(225, 200,50,50);
        addieren.setBounds(275, 300,50,50);
        subtrahieren.setBounds(275, 250,50,50);
        multiplizieren.setBounds(275, 200,50,50);
        dividieren.setBounds(275, 150,50,50);
        ergebnis.setBounds(275, 350,50,50);

        panel2.add(delete);
        panel2.add(zero);
        panel2.add(eins);
        panel2.add(zwei);
        panel2.add(drei);
        panel2.add(vier);
        panel2.add(fuenf);
        panel2.add(sechs);
        panel2.add(sieben);
        panel2.add(acht);
        panel2.add(neun);
        panel2.add(addieren);
        panel2.add(subtrahieren);
        panel2.add(multiplizieren);
        panel2.add(dividieren);
        panel2.add(ergebnis);

        delete.addActionListener(new ListenDelete());
        zero.addActionListener(new ListenZero());
        eins.addActionListener(new ListenEins());
        zwei.addActionListener(new ListenZwei());
        drei.addActionListener(new ListenDrei());
        vier.addActionListener(new ListenVier());
        fuenf.addActionListener(new ListenFuenf());
        sechs.addActionListener(new ListenSechs());
        sieben.addActionListener(new ListenSieben());
        acht.addActionListener(new ListenAcht());
        neun.addActionListener(new ListenNeun());
        addieren.addActionListener(new ListenAddieren());
        subtrahieren.addActionListener(new ListenSubtrahieren());
        multiplizieren.addActionListener(new ListenMultiplizieren());
        dividieren.addActionListener(new ListenDividieren());
        ergebnis.addActionListener(new ListenErgebnis());

        /* JPanel panel2 = new JPanel();
        panel2.setLayout(new FlowLayout());  */

    }

    class ListenDelete implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            interfaceRechner.operators.clear();
            interfaceRechner.numbers.clear();
            interfaceRechner.numbersInt.clear();
            anzeige.setText("");
        }
    }
    class ListenZero implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            anzeige.setText(erg + "0");
            erg = anzeige.getText();
        }
    }
    class ListenEins implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            anzeige.setText(erg + "1");
            erg = anzeige.getText();
            return;
        }
    }
    class ListenZwei implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            anzeige.setText(erg + "2");
            erg = anzeige.getText();
        }
    }
    class ListenDrei implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            anzeige.setText(erg + "3");
            erg = anzeige.getText();
        }
    }
    class ListenVier implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            anzeige.setText(erg + "4");
            erg = anzeige.getText();
        }
    }
    class ListenFuenf implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            anzeige.setText(erg + "5");
            erg = anzeige.getText();
        }
    }
    class ListenSechs implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            anzeige.setText(erg + "6");
            erg = anzeige.getText();
        }
    }
    class ListenSieben implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            anzeige.setText(erg + "7");
            erg = anzeige.getText();
        }
    }
    class ListenAcht implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            anzeige.setText(erg + "8");
            erg = anzeige.getText();
        }
    }
    class ListenNeun implements ActionListener {
    public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            anzeige.setText(erg + "9");
            erg = anzeige.getText();
        }
    }
    class ListenAddieren implements ActionListener {
    public void actionPerformed (ActionEvent e) {
            erg = anzeige.getText();
            interfaceRechner.addNumber(Integer.valueOf(erg));
            interfaceRechner.addOperators("+");
            anzeige.setText("");
            erg = null;
        }
    }
    class ListenSubtrahieren implements ActionListener {

        public void actionPerformed (ActionEvent e) {
                erg = anzeige.getText();
                interfaceRechner.addNumber(Integer.valueOf(erg));
                interfaceRechner.addOperators("-");
                anzeige.setText("");
                erg = null;
            }
        }
    class ListenMultiplizieren implements ActionListener {
        public void actionPerformed (ActionEvent e) {
                erg = anzeige.getText();
                interfaceRechner.addNumber(Integer.valueOf(erg));
                interfaceRechner.addOperators("*");
                anzeige.setText("");
                erg = null;
            }
        }
    class ListenDividieren implements ActionListener {
        public void actionPerformed (ActionEvent e) {
                erg = anzeige.getText();
                interfaceRechner.addNumber(Integer.valueOf(erg));
                interfaceRechner.addOperators("/");
                anzeige.setText("");
                erg = null;
            }
        }
    class ListenErgebnis implements ActionListener {
        public void actionPerformed (ActionEvent e) {
                erg = anzeige.getText();
                interfaceRechner.addNumber(Integer.valueOf(erg));
                interfaceRechner.addOperators("=");
                anzeige.setText(""+interfaceRechner.berechneInt());

            }
        }

}

问题是：打游戏时：

public class Main {
    public static void main(String[] args) {
        Interface interface1 =new Interface();
        interface1.show();
    }
}

没有显示任何面板。一个小小的java窗口弹出，无论我如何配置——直接在面板中或通过JFrame——它都不会影响任何东西。现在有一些代码是多余的，我把它放在那里是为了记住我已经尝试过的东西。但我似乎找不到合适的解决办法

打开的窗口总是空的，没有按钮，顶部没有菜单栏

这里：

public void Interface(){

这不是一个构造函数

你需要

public Interface() {

---

相反。除此之外：使用有意义的名称。接口没有说明它背后的组件。为什么不叫它GuiFrame，或者类似的东西呢？

缺少类：RechnerIntpublic类接口扩展了JFrame{public void Interface{->这有什么意义？请删除该行中的void，不要忘记删除不再需要的注释-