运行文件不使用Swing更新GUI中的更改

Question

我正在使用Swing登录屏幕。我编辑了屏幕上唯一的按钮“ Entrar”的enable属性，如下图所示：

Login screen

但是，当我按下Shift-F6（运行文件）时，它没有显示更改：

Login Screen after running single file

代码如下：

package view;

import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
/**
 *
 * @author User
 */
public class Inicio extends javax.swing.JFrame {

    String usuario;
    String senha;

    int a;

    public Inicio() {  

        initComponents();

        DocumentListener dUsuario = new DocumentListener(){
            @Override
            public void insertUpdate(DocumentEvent e) {
                try {
                    usuario = e.getDocument().getText(0, 0);
                    a = 1;
                } catch (BadLocationException ex) {
                    Logger.getLogger(Inicio.class.getName()).log(Level.SEVERE, null, ex);
                }
            }

            @Override
            public void removeUpdate(DocumentEvent e) {
                throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
            }

            @Override
             public void changedUpdate(DocumentEvent e) {
                try {
                    usuario = e.getDocument().getText(0, 0);
                    a = 1;
                } catch (BadLocationException ex) {
                    Logger.getLogger(Inicio.class.getName()).log(Level.SEVERE, null, ex);
                }
            }    

        };

        DocumentListener dSenha = new DocumentListener(){
            @Override
            public void insertUpdate(DocumentEvent e) {
                try {
                    senha = e.getDocument().getText(0, 0);
                    a = 2;
                } catch (BadLocationException ex) {
                    Logger.getLogger(Inicio.class.getName()).log(Level.SEVERE, null, ex);
                }
            }

            @Override
            public void removeUpdate(DocumentEvent e) {
                throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
            }

            @Override
            public void changedUpdate(DocumentEvent e) {
                try {
                    senha = e.getDocument().getText(0, 0);
                    a = 2;
                } catch (BadLocationException ex) {
                    Logger.getLogger(Inicio.class.getName()).log(Level.SEVERE, null, ex);
                }
            }   

        };

        tUsuario.getDocument().addDocumentListener(dUsuario);
        tSenha.getDocument().addDocumentListener(dSenha);

        if(a == 2) {
            if (bEntrar.isEnabled() == false) {
                bEntrar.setEnabled(true);
            }

        }else{
            if (bEntrar.isEnabled() == true) {
                bEntrar.setEnabled(false);
            }

        }

    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        tSenha = new javax.swing.JPasswordField();
        jLabel3 = new javax.swing.JLabel();
        jLabel4 = new javax.swing.JLabel();
        tUsuario = new javax.swing.JFormattedTextField();
        bEntrar = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setResizable(false);

        jLabel1.setForeground(new java.awt.Color(153, 153, 153));
        jLabel1.setText("Informe apenas os dígitos do CPF.");

        jLabel2.setText("Senha:");

        jLabel3.setText("CPF:");

        jLabel4.setFont(new java.awt.Font("Tahoma", 0, 18)); // NOI18N
        jLabel4.setText("LOGIN");

        try {
            tUsuario.setFormatterFactory(new javax.swing.text.DefaultFormatterFactory(new javax.swing.text.MaskFormatter("###.###.###-##")));
        } catch (java.text.ParseException ex) {
            ex.printStackTrace();
        }

        bEntrar.setText("Entrar");
        bEntrar.setEnabled(false);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(184, 184, 184)
                .addComponent(jLabel4)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addGap(0, 91, Short.MAX_VALUE)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jLabel3, javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(jLabel2, javax.swing.GroupLayout.Alignment.TRAILING))
                .addGap(7, 7, 7)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jLabel1)
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
                        .addComponent(tSenha, javax.swing.GroupLayout.Alignment.LEADING)
                        .addComponent(bEntrar, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 129, Short.MAX_VALUE))
                    .addComponent(tUsuario, javax.swing.GroupLayout.PREFERRED_SIZE, 128, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(55, 55, 55))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(50, 50, 50)
                .addComponent(jLabel4)
                .addGap(37, 37, 37)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel3)
                    .addComponent(tUsuario, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(3, 3, 3)
                .addComponent(jLabel1)
                .addGap(9, 9, 9)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2)
                    .addComponent(tSenha, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 58, Short.MAX_VALUE)
                .addComponent(bEntrar)
                .addGap(41, 41, 41))
        );

        pack();
    }// </editor-fold>                        




    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Inicio().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton bEntrar;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JPasswordField tSenha;
    private javax.swing.JFormattedTextField tUsuario;
    // End of variables declaration                   


}

我使用Swing中的Project视图编辑了按钮属性。那么，我该怎么做才能解决此问题？是Netbeans错误吗？顺便说一下，我正在使用Netbeans IDE 8.2。

Answer 1

如果您要基于文本字段上发生的更改来影响按钮的状态，则这些动作需要在动作处理程序本身（即$(".go_btn").click(function(){ const number = $(".go_input").val(); if(number == 1){ $('html, body').animate({ 'scrollTop' : $("#index_first").offset().bottom }); } $('html, body').animate({ 'scrollTop' : $("#index_"+number).offset().top }); }) s）中进行

以下是一个非常基本的示例，它将禁用“操作”按钮，直到用户名和密码字段都不再为空为止

DocumentListener

  

为什么初始状态未更新？

您将import java.awt.EventQueue; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JPasswordField; import javax.swing.JTextField; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; public class Test { public static void main(String[] args) { new Test(); } public Test() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { ex.printStackTrace(); } JFrame frame = new JFrame("Testing"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.add(new TestPane()); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } public class TestPane extends JPanel { private JTextField userNameField; private JPasswordField passwordField; private JButton actionButton; public TestPane() { userNameField = new JTextField(15); passwordField = new JPasswordField(15); actionButton = new JButton("Do stuff"); actionButton.setEnabled(false); DocumentListener documentListener = new DocumentListener() { protected void stateDidChange() { actionButton.setEnabled(userNameField.getText().length() > 0 && passwordField.getPassword().length > 0); } @Override public void insertUpdate(DocumentEvent e) { stateDidChange(); } @Override public void removeUpdate(DocumentEvent e) { stateDidChange(); } @Override public void changedUpdate(DocumentEvent e) { stateDidChange(); } }; userNameField.getDocument().addDocumentListener(documentListener); passwordField.getDocument().addDocumentListener(documentListener); setLayout(new GridBagLayout()); GridBagConstraints gbc = new GridBagConstraints(); gbc.gridwidth = gbc.REMAINDER; add(userNameField, gbc); add(passwordField, gbc); add(actionButton, gbc); } } } 定义为...。

int a;

为其赋予初始值（或默认值）a。

然后您使用...

if（a == 2）{         如果（bEntrar.isEnabled（）==否）{             bEntrar.setEnabled（true）;         }

0

更改初始状态。由于}else{ if (bEntrar.isEnabled() == true) { bEntrar.setEnabled(false); } } 为a，因此执行了0块，因此将按钮启用状态更改为else的唯一条件是当前启用状态为{{1 }}

  

但是当我使用Shift + F6键运行代码时，它不起作用

执行“清理并生成”并运行项目，而不是文件。在测试您的代码时，显示的用户界面带有已禁用的按钮