Réglage méthode public void pour JTextField

Question

Lorsque le programme est exécuté type void admis dans cette erreur montre Program error

resultField.setText ((ai.inOrder (ai.root))); provoque l'erreur ci-dessus

Je souhaite que le contenu du tableau soit transmis à la classe BST. java est ensuite renvoyé dans Result TextField.

Comment résoudre ce problème?

Ci-dessous est le code

MAIN

package p3gui; 

import javax.swing.JButton; 
import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JTextField; 
import java.awt.event.*; 
import javax.swing.ButtonGroup; 
import javax.swing.JOptionPane; 
import javax.swing.JRadioButton; 

public class P3GUI extends JFrame { 

    JFrame f = new JFrame("Binary Search Tree Sort");// Title 

    private final JButton evaluate; 
    private final JLabel textfieldLabel; 
    private final JTextField entryField; 
    private final JLabel resutfieldlabel; 
    private final JLabel radioLabel1; 
    private final JLabel radioLabel2; 
    private final JTextField resultField; 
    private final JRadioButton ascending; 
    private final JRadioButton descending; 
    private final JRadioButton integer; 
    private final JRadioButton fraction; 
    private final ButtonGroup radioButtons = new ButtonGroup(); 
    private final ButtonGroup radioButtons2 = new ButtonGroup(); 
    private final JOptionPane popup = new JOptionPane(); 

    P3GUI() 
    { 
     f.setSize(425, 375); 
     f.setLayout(null);//using no layout managers 
     f.setVisible(true);//making the frame visible //window size 
     f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 


     radioLabel2 = new JLabel(" Numeric Type "); 
     f.add(radioLabel2); 
     radioLabel2.setBounds(225, 275, 100, 15); 

     integer = new JRadioButton(" Integer "); 
     radioButtons.add(integer); 
     f.add(integer); 
     integer.setBounds(225, 295, 160, 15); 

     fraction = new JRadioButton(" Fraction "); 
     radioButtons.add(fraction); 
     f.add(fraction); 
     fraction.setBounds(225, 315, 160, 15); 

     radioLabel1 = new JLabel(" Sorted Order "); 
     f.add(radioLabel1); 
     radioLabel1.setBounds(10, 275, 100, 15); 


     ascending = new JRadioButton(" Ascending "); 
     radioButtons2.add(ascending); 
     f.add(ascending); 
     ascending.setBounds(10, 295, 160, 15); 

     descending = new JRadioButton(" Descending "); 
     radioButtons2.add(descending); 
     f.add(descending); 
     descending.setBounds(10, 315, 160, 15); 

     textfieldLabel = new JLabel(" Original List "); 
     f.add(textfieldLabel); 
     textfieldLabel.setBounds(42, 10, 160, 25); 

     entryField = new JTextField(""); 
     //entryField.addActionListener(this);//ActionListener 
     f.add(entryField); 
     entryField.setBounds(118, 10, 245, 25); 


     evaluate = new JButton(" Perform Sort "); 
     f.add(evaluate); 
     evaluate.setBounds(137, 180, 130, 30); 


     resutfieldlabel = new JLabel(" Sorted List "); 
     f.add(resutfieldlabel); 
     resutfieldlabel.setBounds(52, 100, 100, 25); 

     resultField = new JTextField(""); 
     //resultField.addActionListener(this);//ActionListener 
     resultField.setEditable(false); 
     f.add(resultField); 
     resultField.setBounds(125, 100, 220, 25); 

     evaluate.addActionListener(new getItListener()); 

    }//END of P3GUI 

    class getItListener implements ActionListener { 

     @Override 
     public void actionPerformed(ActionEvent e) { 
      String text; 

      /*text = entryField.getText().trim(). replaceAll(" ",""); 
      String textArray[] = text.split(" ");*/ 
      text = getAmtValue(); 
      String textArray[] = text.split(" "); 

      if (ascending.isSelected() && integer.isSelected()) { 

       BST ai = new BST(new Integer(textArray[0])); 
       for (int i = 1; i < textArray.length; i++) { 
        ai.insert(ai.root, new Integer(textArray[i])); 
       } 
       resultField.setText((ai.inOrder(ai.root))); 


      } else if (descending.isSelected() && integer.isSelected()) { 
       //Do Something 
      } else if (ascending.isSelected() && fraction.isSelected()) { 
       // Do Something 
      } else if (descending.isSelected() && fraction.isSelected()) { 
       // Do Something 
      } else { 
       JOptionPane.showMessageDialog(popup, "Please enter valid 
      amount."); 
      } 
     } 
    } 

    public String getAmtValue() { 
     try { 
      return (entryField.getText().trim().replaceAll(" ", "")); 
     } catch (NumberFormatException e) { 
      System.out.println("This is not a number"); 
      eraseTextField(); 
      return ""; 
     } 
    } 

    //clears text field 
    public void eraseTextField() { 
     entryField.setText(""); 
     entryField.requestFocus(); 
    } 

    public static void main(String[] args) { 
     P3GUI p3GUI; 
     p3GUI = new P3GUI(); 

    } 
} 

paquet p3gui;

class Node { 

    public Object element; 
    public Node left; 
    public Node right; 

    // CONSTRUCTORS 
    public Node(Object theElement) { 
     this(theElement, null, null); 
    } 

    public Node(Object theElement, Node lLink, Node rLink) { 
     element = theElement; 
     this.left = lLink; 
     this.right = rLink; 
    } 
} 

BST.Java

public class BST { 

    public Node root; 

    public BST(Object x) { // ONLY CONSTRUCTOR// 
     root = new Node(x); 
    } 


    public Node insert(Node node, Integer x) { 
     if (node == null) { 
      return node = new Node(x); 
     } 
     if (x < (Integer) node.element) { 
      node.left = insert(node.left, x); 
     } else { 
      node.right = insert(node.right, x); 
     } 
     return node; 
    } 


    /** 
    * 
    * @param node 
    */ 
    public void inOrder(Node node) { 
     if (node != null) { 
      inOrder(node.left); 

      inOrder(node.right); 
     } 
    } 


    /** 
    * 
    * @param node 
    */ 
    public void descOrder(Node node) { 
     if (node != null) { 
      descOrder(node.right); 

      descOrder(node.left); 
     } 
    } 
} 

Answer 1

Votre problème est que votre méthode afinde est une méthode vide. Vous ne pouvez pas définir la valeur de texte de votre champ avec une méthode void, car une méthode void ne renvoie rien.

Si la méthode inOrder renvoyait une chaîne, ce serait parfait.