事件处理Swing组件(Event Handling Swing components)

 我正在尝试一点一点地学习Java，重新创建我用Python完成的应用程序 - 一个非常基础的库控制软件。 但是，我遇到了问题，因为事件处理，主要是因为（我认为）我在没有太多了解情况的情况下全面了解了Swing，但在我去的时候搞清楚了。 
 
 到目前为止，这是我的代码： 
 
public class SEHBV extends JFrame{

    public SEHBV(){

        super("SEHBV Biblio 2.0");
        ImageIcon img = new ImageIcon("books.ico");
        setIconImage(img.getImage());

        JPanel p_ini, locar, devolver, buscar, administrar;
        JLabel l_dia, l_mes, l_ano, loca_cs, loca_cl, loca_prazo, loca_cb, locado_state;
        JTextField dia, mes, ano, loca_cs_tf, loca_cl_tf, loca_prazo_tf, loca_cb_tf, devolve_cod;
        JTextArea loca_prazo_data, loca_oper_res, mostra_multa;
        JButton data, loca_cb_bt, loca_commit, ver_multa;
        JList<String> loca_s_res, loca_cb_res, atrasos, locados;


        p_ini = new JPanel(new GridBagLayout());
        GridBagConstraints i = new GridBagConstraints();
        l_dia = new JLabel("Dia: ");
        l_mes = new JLabel("Mês: ");
        l_ano = new JLabel("Ano: ");
        dia = new JTextField(6);
        mes = new JTextField(6);
        ano = new JTextField(6);
        data = new JButton("Afirmar Data");
        atrasos = new JList<String>();  
        atrasos.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        atrasos.setLayoutOrientation(JList.VERTICAL);
        atrasos.setVisibleRowCount(10);
        JScrollPane scroll_atrasos = new JScrollPane(atrasos);
        atrasos.setBackground(Color.WHITE);
        atrasos.setBorder(BorderFactory.createEtchedBorder(EtchedBorder.LOWERED));

        i.fill = GridBagConstraints.HORIZONTAL;
        i.gridx = 0;
        i.gridy = 0;
        p_ini.add(l_dia, i);
        i.gridx = 1;
        p_ini.add(dia, i);
        i.gridx = 2;
        p_ini.add(l_mes, i);
        i.gridx = 3;
        p_ini.add(mes, i);
        i.gridx = 4;
        p_ini.add(l_ano, i);
        i.gridx = 5;
        p_ini.add(ano, i);
        i.gridx = 6;
        p_ini.add(data, i);
        i.gridy = 1;
        i.gridx = 0;
        i.gridwidth = 7;
        p_ini.add(scroll_atrasos, i);

        //GUI Locação 
        locar = new JPanel(new GridBagLayout());
        GridBagConstraints l = new GridBagConstraints();
        l.gridx = 0;
        l.gridy = 0;
        JPanel loca_socios = new JPanel(new FlowLayout());
        JPanel loca_oper = new JPanel(new GridBagLayout());
        GridBagConstraints o = new GridBagConstraints();
        JPanel loca_busca = new JPanel(new GridBagLayout());
        GridBagConstraints b = new GridBagConstraints();


        locar.add(loca_socios, l); //Busca de Sócios na janela de Locação

        loca_s_res = new JList<String>();
        loca_s_res.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        loca_s_res.setLayoutOrientation(JList.VERTICAL);
        loca_s_res.setModel(Runner.nome_socios);
        loca_s_res.setVisibleRowCount(25);
        JScrollPane scroll_loca_s = new JScrollPane(loca_s_res);
        loca_s_res.setBorder(BorderFactory.createEtchedBorder(EtchedBorder.LOWERED));
        loca_socios.add(scroll_loca_s);

        l.gridx = 1;
        locar.add(loca_oper, l); //Locação propriamente dita
        o.weighty = 1;
        o.weightx = 1;
        o.anchor = GridBagConstraints.NORTHWEST;
        o.insets = new Insets(1,1,1,1);
        loca_cs = new JLabel("Código do Sócio: ");
        o.fill = GridBagConstraints.HORIZONTAL;
        o.gridx = 0;
        o.gridy = 0;
        loca_oper.add(loca_cs, o);

        loca_cs_tf = new JTextField(5);
        loca_cs_tf.setEditable(false);
        loca_cs_tf.setBackground(Color.WHITE);
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 1;
        o.gridy = 0;
        loca_oper.add(loca_cs_tf, o);

        loca_cl = new JLabel("Código do Livro: ");
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 0;
        o.gridy = 1;
        loca_oper.add(loca_cl, o);

        loca_cl_tf = new JTextField(5);
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 1;
        o.gridy = 1;
        loca_oper.add(loca_cl_tf, o);

        loca_prazo = new JLabel("Prazo para devolução (em dias): ");
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 0;
        o.gridy = 2;
        loca_oper.add(loca_prazo, o);

        loca_prazo_tf = new JTextField(5);
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 1;
        o.gridy = 2;
        loca_oper.add(loca_prazo_tf, o);

        loca_prazo_data = new JTextArea();
        loca_prazo_data.setBackground(getForeground());
        o.gridx = 0;
        o.gridy = 3;
        o.gridwidth = 3;
        loca_oper.add(loca_prazo_data, o);

        loca_commit = new JButton("Realizar Locação");
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 0;
        o.gridy = 4;
        o.gridwidth = 3;
        loca_oper.add(loca_commit, o);


        loca_oper_res = new JTextArea();
        loca_oper_res.setBackground(getForeground());
        o.gridy = 5;
        loca_oper.add(loca_oper_res, o);

        l.gridx = 2;
        locar.add(loca_busca, l);
        loca_cb = new JLabel("Chave de Busca: ");
        b.fill = GridBagConstraints.HORIZONTAL;
        b.gridx = 0;
        b.gridy = 0;
        loca_busca.add(loca_cb, b);

        loca_cb_tf = new JTextField(20);
        b.fill = GridBagConstraints.HORIZONTAL;
        b.gridx = 1;
        b.gridy = 0;
        loca_busca.add(loca_cb_tf, b);

        loca_cb_bt = new JButton("Busca Rápida");
        b.fill = GridBagConstraints.HORIZONTAL;
        b.gridx = 2;
        b.gridy = 0;
        loca_busca.add(loca_cb_bt, b);

        loca_cb_res = new JList<String>();
        loca_cb_res.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        loca_cb_res.setLayoutOrientation(JList.VERTICAL);
        b.fill = GridBagConstraints.HORIZONTAL;
        loca_cb_res.setBorder(BorderFactory.createEtchedBorder(EtchedBorder.LOWERED));
        b.gridx = 0;
        b.gridy = 1;
        b.gridwidth = 3;
        b.gridheight = 2;
        loca_cb_res.setVisibleRowCount(25);
        JScrollPane scroll_loca_cb = new JScrollPane(loca_cb_res);
        loca_cb_res.setBorder(BorderFactory.createEtchedBorder(EtchedBorder.LOWERED));
        loca_busca.add(scroll_loca_cb, b);


    // Other Tabs of the GUI


    //GUI Geral
    JTabbedPane tp = new JTabbedPane();

    tp.addTab("Página inicial (Alt+I)", null, p_ini, "pág. inicial");
    tp.addTab("Locação (Alt+L)", locar);
    tp.addTab("Devolução (Alt+D)", devolver);
    tp.addTab("Busca Avançada (Alt+B)", buscar);
    tp.addTab("Administração (Alt+A)", administrar);
    tp.setMnemonicAt(0, KeyEvent.VK_I);
    tp.setMnemonicAt(1, KeyEvent.VK_L);
    tp.setMnemonicAt(2, KeyEvent.VK_D);
    tp.setMnemonicAt(3, KeyEvent.VK_B);
    tp.setMnemonicAt(4, KeyEvent.VK_A);

    add(tp);
}
 
 所以，假设我正在尝试处理loca_commit JButton的点击。 我正在尝试创建一个事件处理程序 - 根据Java教程和其他StackOverflow问题/答案 - 但处理程序不识别loca_commit 。 现在我只是想让它工作，然后我会用它来调用一个方法，但如果我不能让它创建一个弹出窗口，那么，你明白了。 
 
 所以，到目前为止我的处理程序代码是这样的： 
 
    private class LocaHandler implements ActionListener{
        public void actionPerformed(ActionEvent event){

            String string = "";

            if(event.getSource()==loca_commit)
                string=String.format("Botão Apertado");

        JOptionPane.showMessageDialog(null, string);
        }
 
 你们能在这里点亮一下吗？ 

I'm trying to learn Java bit by bit, recreating an application I completed in Python - a library control software, very basic. I am having problems, though, with Event Handling, primarily because (I think) I went full-blown in to Swing without knowing much about it, but figuring it out as I went. 
 
Here's my code, so far:
 
public class SEHBV extends JFrame{

    public SEHBV(){

        super("SEHBV Biblio 2.0");
        ImageIcon img = new ImageIcon("books.ico");
        setIconImage(img.getImage());

        JPanel p_ini, locar, devolver, buscar, administrar;
        JLabel l_dia, l_mes, l_ano, loca_cs, loca_cl, loca_prazo, loca_cb, locado_state;
        JTextField dia, mes, ano, loca_cs_tf, loca_cl_tf, loca_prazo_tf, loca_cb_tf, devolve_cod;
        JTextArea loca_prazo_data, loca_oper_res, mostra_multa;
        JButton data, loca_cb_bt, loca_commit, ver_multa;
        JList<String> loca_s_res, loca_cb_res, atrasos, locados;


        p_ini = new JPanel(new GridBagLayout());
        GridBagConstraints i = new GridBagConstraints();
        l_dia = new JLabel("Dia: ");
        l_mes = new JLabel("Mês: ");
        l_ano = new JLabel("Ano: ");
        dia = new JTextField(6);
        mes = new JTextField(6);
        ano = new JTextField(6);
        data = new JButton("Afirmar Data");
        atrasos = new JList<String>();  
        atrasos.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        atrasos.setLayoutOrientation(JList.VERTICAL);
        atrasos.setVisibleRowCount(10);
        JScrollPane scroll_atrasos = new JScrollPane(atrasos);
        atrasos.setBackground(Color.WHITE);
        atrasos.setBorder(BorderFactory.createEtchedBorder(EtchedBorder.LOWERED));

        i.fill = GridBagConstraints.HORIZONTAL;
        i.gridx = 0;
        i.gridy = 0;
        p_ini.add(l_dia, i);
        i.gridx = 1;
        p_ini.add(dia, i);
        i.gridx = 2;
        p_ini.add(l_mes, i);
        i.gridx = 3;
        p_ini.add(mes, i);
        i.gridx = 4;
        p_ini.add(l_ano, i);
        i.gridx = 5;
        p_ini.add(ano, i);
        i.gridx = 6;
        p_ini.add(data, i);
        i.gridy = 1;
        i.gridx = 0;
        i.gridwidth = 7;
        p_ini.add(scroll_atrasos, i);

        //GUI Locação 
        locar = new JPanel(new GridBagLayout());
        GridBagConstraints l = new GridBagConstraints();
        l.gridx = 0;
        l.gridy = 0;
        JPanel loca_socios = new JPanel(new FlowLayout());
        JPanel loca_oper = new JPanel(new GridBagLayout());
        GridBagConstraints o = new GridBagConstraints();
        JPanel loca_busca = new JPanel(new GridBagLayout());
        GridBagConstraints b = new GridBagConstraints();


        locar.add(loca_socios, l); //Busca de Sócios na janela de Locação

        loca_s_res = new JList<String>();
        loca_s_res.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        loca_s_res.setLayoutOrientation(JList.VERTICAL);
        loca_s_res.setModel(Runner.nome_socios);
        loca_s_res.setVisibleRowCount(25);
        JScrollPane scroll_loca_s = new JScrollPane(loca_s_res);
        loca_s_res.setBorder(BorderFactory.createEtchedBorder(EtchedBorder.LOWERED));
        loca_socios.add(scroll_loca_s);

        l.gridx = 1;
        locar.add(loca_oper, l); //Locação propriamente dita
        o.weighty = 1;
        o.weightx = 1;
        o.anchor = GridBagConstraints.NORTHWEST;
        o.insets = new Insets(1,1,1,1);
        loca_cs = new JLabel("Código do Sócio: ");
        o.fill = GridBagConstraints.HORIZONTAL;
        o.gridx = 0;
        o.gridy = 0;
        loca_oper.add(loca_cs, o);

        loca_cs_tf = new JTextField(5);
        loca_cs_tf.setEditable(false);
        loca_cs_tf.setBackground(Color.WHITE);
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 1;
        o.gridy = 0;
        loca_oper.add(loca_cs_tf, o);

        loca_cl = new JLabel("Código do Livro: ");
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 0;
        o.gridy = 1;
        loca_oper.add(loca_cl, o);

        loca_cl_tf = new JTextField(5);
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 1;
        o.gridy = 1;
        loca_oper.add(loca_cl_tf, o);

        loca_prazo = new JLabel("Prazo para devolução (em dias): ");
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 0;
        o.gridy = 2;
        loca_oper.add(loca_prazo, o);

        loca_prazo_tf = new JTextField(5);
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 1;
        o.gridy = 2;
        loca_oper.add(loca_prazo_tf, o);

        loca_prazo_data = new JTextArea();
        loca_prazo_data.setBackground(getForeground());
        o.gridx = 0;
        o.gridy = 3;
        o.gridwidth = 3;
        loca_oper.add(loca_prazo_data, o);

        loca_commit = new JButton("Realizar Locação");
        o.fill = GridBagConstraints.BOTH;
        o.gridx = 0;
        o.gridy = 4;
        o.gridwidth = 3;
        loca_oper.add(loca_commit, o);


        loca_oper_res = new JTextArea();
        loca_oper_res.setBackground(getForeground());
        o.gridy = 5;
        loca_oper.add(loca_oper_res, o);

        l.gridx = 2;
        locar.add(loca_busca, l);
        loca_cb = new JLabel("Chave de Busca: ");
        b.fill = GridBagConstraints.HORIZONTAL;
        b.gridx = 0;
        b.gridy = 0;
        loca_busca.add(loca_cb, b);

        loca_cb_tf = new JTextField(20);
        b.fill = GridBagConstraints.HORIZONTAL;
        b.gridx = 1;
        b.gridy = 0;
        loca_busca.add(loca_cb_tf, b);

        loca_cb_bt = new JButton("Busca Rápida");
        b.fill = GridBagConstraints.HORIZONTAL;
        b.gridx = 2;
        b.gridy = 0;
        loca_busca.add(loca_cb_bt, b);

        loca_cb_res = new JList<String>();
        loca_cb_res.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        loca_cb_res.setLayoutOrientation(JList.VERTICAL);
        b.fill = GridBagConstraints.HORIZONTAL;
        loca_cb_res.setBorder(BorderFactory.createEtchedBorder(EtchedBorder.LOWERED));
        b.gridx = 0;
        b.gridy = 1;
        b.gridwidth = 3;
        b.gridheight = 2;
        loca_cb_res.setVisibleRowCount(25);
        JScrollPane scroll_loca_cb = new JScrollPane(loca_cb_res);
        loca_cb_res.setBorder(BorderFactory.createEtchedBorder(EtchedBorder.LOWERED));
        loca_busca.add(scroll_loca_cb, b);


    // Other Tabs of the GUI


    //GUI Geral
    JTabbedPane tp = new JTabbedPane();

    tp.addTab("Página inicial (Alt+I)", null, p_ini, "pág. inicial");
    tp.addTab("Locação (Alt+L)", locar);
    tp.addTab("Devolução (Alt+D)", devolver);
    tp.addTab("Busca Avançada (Alt+B)", buscar);
    tp.addTab("Administração (Alt+A)", administrar);
    tp.setMnemonicAt(0, KeyEvent.VK_I);
    tp.setMnemonicAt(1, KeyEvent.VK_L);
    tp.setMnemonicAt(2, KeyEvent.VK_D);
    tp.setMnemonicAt(3, KeyEvent.VK_B);
    tp.setMnemonicAt(4, KeyEvent.VK_A);

    add(tp);
}
 
So, lets say I'm trying to handle the clicking of the loca_commit JButton. I'm trying to create an Event Handler - according to Java tutorials and other StackOverflow questions/answers - but the handler does not identify loca_commit. Right now I'm just trying to get it to work, then I'll use it for calling a method, but if I can't make it create a pop up, well, you get my point. 
 
So, my code for the handler so far is this:
 
    private class LocaHandler implements ActionListener{
        public void actionPerformed(ActionEvent event){

            String string = "";

            if(event.getSource()==loca_commit)
                string=String.format("Botão Apertado");

        JOptionPane.showMessageDialog(null, string);
        }
 
Can you guys shed a light here?

原文：https://stackoverflow.com/questions/42825348