Wie erhalten Sie eine Reihe von Tasten in einer festen Position?

Question

Ich muss einen sehr einfachen Rechner machen und die Knöpfe (addieren, subtrahieren, dividieren und multiplizieren) müssen unterhalb der Zahleneingabe sein und ergeben eine feste Position. In der picture zeigt was ich haben soll und auf der anderen Seite zeigt es was ich gerade habe.

package calculator; 
import java.awt.*; 
import java.awt.event.*; 
import javax.swing.*; 
import java.awt.BorderLayout; 




public class Calculator extends JFrame { 
private JTextField Number1TxtField; 
private JTextField Number2TxtField; 
private JTextField ResultTxtField; 
private JButton add; 
private JButton subtract; 
private JButton multiply; 
private JButton divide; 



public Calculator() { // class for the calculator 




     setLayout(new FlowLayout(FlowLayout.LEFT,8,10)); 
     add(new JLabel("Number 1")); 
     Number1TxtField=new JTextField(8); add(Number1TxtField); 
     add(new JLabel("Number 2")); 
     Number2TxtField=new JTextField(8); 
     Number2TxtField=new JTextField(8); add(Number2TxtField); 
     add(new JLabel("Result")); 
     ResultTxtField= new JTextField(8); add(ResultTxtField); 
     ResultTxtField.setEditable(false); add(ResultTxtField); 




     //new JPanel 
     add = new JButton("Add"); add(add); 

     subtract = new JButton ("Subtract"); add(subtract); 

     multiply = new JButton ("Multiply"); add(multiply); 

     divide = new JButton ("Divide"); add(divide); 


     ButtonListener btnlistener = new ButtonListener(); 

     add.addActionListener(btnlistener); 

     subtract.addActionListener(btnlistener); 

     multiply.addActionListener(btnlistener); 

     divide.addActionListener(btnlistener); 
    } 

class ButtonListener implements ActionListener { 

     @Override 

     public void actionPerformed(ActionEvent e) { 

String num1str = Number1TxtField.getText(); 

double num1 = Double.parseDouble(num1str); 

String num2str = Number2TxtField.getText(); 

double num2 = Double.parseDouble(num2str); 

double result; 

     if (e.getSource() == add) 
      result = num1+num2; 

     else if (e.getSource() == subtract) 
    result = num1-num2; 

     else if (e.getSource() == multiply) 
    result = num1*num2; 

     else //DivideButton 
    result = num1/num2; 


ResultTxtField.setText(String.valueOf(result)); 

    } 
    } 



     public static void main(String[] args) { 



     Calculator frame = new Calculator(); 

     frame.setTitle("Calculator"); 

     frame.setSize(600,120); 

     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

     frame.setVisible(true); 
    } 
} 

Answer 1

Erstellen Sie zwei Panel: topPanel und buttonsPanel. Fügen Sie Ihre Knöpfe zur buttonsPanel hinzu und fügen Sie diese Verkleidung der Position der JFrame hinzu. Fügen Sie dann Ihre Textfelder zur topPanel hinzu und setzen Sie topPanel auf die NORTH-Position der JFrame.

import java.awt.BorderLayout; 
import java.awt.Dimension; 
import java.awt.FlowLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 

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

public class Calculator extends JFrame { 
    private JTextField Number1TxtField; 
    private JTextField Number2TxtField; 
    private JTextField ResultTxtField; 
    private JButton add; 
    private JButton subtract; 
    private JButton multiply; 
    private JButton divide; 

    public Calculator() { // class for the calculator 

     JPanel topPanel = new JPanel(); 

     topPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 8, 5)); 
     topPanel.add(new JLabel("Number 1")); 
     Number1TxtField = new JTextField(5); 
     topPanel.add(Number1TxtField); 
     topPanel.add(new JLabel("Number 2")); 
     Number2TxtField = new JTextField(5); 
     topPanel.add(Number2TxtField); 
     topPanel.add(new JLabel("Result")); 
     ResultTxtField = new JTextField(8); 
     topPanel.add(ResultTxtField); 
     ResultTxtField.setEditable(false); 
     topPanel.add(ResultTxtField); 

     // new JPanel 
     JPanel buttonsPanel = new JPanel(); 
     buttonsPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 8, 5)); 
     add = new JButton("Add"); 
     buttonsPanel.add(add); 

     subtract = new JButton("Subtract"); 
     buttonsPanel.add(subtract); 

     multiply = new JButton("Multiply"); 
     buttonsPanel.add(multiply); 

     divide = new JButton("Divide"); 
     buttonsPanel.add(divide); 

     ButtonListener btnlistener = new ButtonListener(); 

     add.addActionListener(btnlistener); 

     subtract.addActionListener(btnlistener); 

     multiply.addActionListener(btnlistener); 

     divide.addActionListener(btnlistener); 

     getContentPane().add(topPanel, BorderLayout.NORTH); 
     getContentPane().add(buttonsPanel); 
    } 

    class ButtonListener implements ActionListener { 

     @Override 

     public void actionPerformed(ActionEvent e) { 

      String num1str = Number1TxtField.getText(); 

      double num1 = Double.parseDouble(num1str); 

      String num2str = Number2TxtField.getText(); 

      double num2 = Double.parseDouble(num2str); 

      double result; 

      if (e.getSource() == add) 
       result = num1 + num2; 

      else if (e.getSource() == subtract) 
       result = num1 - num2; 

      else if (e.getSource() == multiply) 
       result = num1 * num2; 

      else // DivideButton 
       result = num1/num2; 

      ResultTxtField.setText(String.valueOf(result)); 

     } 
    } 

    public static void main(String[] args) { 

     Calculator frame = new Calculator(); 

     frame.setTitle("Calculator"); 

     frame.pack(); 

     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

     frame.setVisible(true); 
    } 
}