【JAVA】-- 简易超市管理系统窗口（六）

下面将完成“查询内容”的相关功能，实现可查询订单记录。

实例化Cha类对象

    private Cha chaPanel = null;

private Cha getCha(){
        if(chaPanel == null){
            chaPanel = new Cha();
            chaPanel.setName("chaPanel");
        }
        return chaPanel;
    }

getMainPanel方法增加

将Cha类对象添加到JPanel功能面板组件上。

mainPanel.add(getCha(),getCha().getName());

getChaButton方法增加/修改

为“查询内容”增加鼠标点击事件，实现点击切换页面

chaButton.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    CardLayout layout = (CardLayout) mainPanel.getLayout();
                    layout.show(getMainPanel(),"chaPanel");
                }
            });

 public JPanel panel;
    public JButton button1;//开始查询按钮
    public Cha(){
        super();
        this.setSize(352,302);
        this.setOpaque(false);
        this.setLayout(new BorderLayout());
        panel = new JPanel();
        panel.setLayout(new GridBagLayout());
        panel.setOpaque(false);
        this.add(panel,BorderLayout.CENTER);
        GridBagConstraints gridBagConstraints1 = new GridBagConstraints();
        gridBagConstraints1.gridx = 0;
        gridBagConstraints1.gridy = 0;
        gridBagConstraints1.insets = new Insets(5,5,5,5);
        button1 = new JButton("开始查询");
        button1.setFont(new Font("华文行楷",Font.BOLD,15));
        button1.setOpaque(false);
        button1.setBorderPainted(false);
        button1.setContentAreaFilled(false);
        button1.setFocusPainted(false);
        panel.add(button1,gridBagConstraints1);
    }

    public JComboBox box1;

 构造方法增加

 box1 = new JComboBox();
        GridBagConstraints gridBagConstraints2 = new GridBagConstraints();
        gridBagConstraints2.gridx = 0;
        gridBagConstraints2.gridy = 1;
        gridBagConstraints2.insets = new Insets(5,5,5,5);
        gridBagConstraints2.gridwidth = 2;
        gridBagConstraints1.weightx = 1.0;
        gridBagConstraints2.fill = GridBagConstraints.HORIZONTAL;
        panel.add(box1,gridBagConstraints2);

 public JLabel label2;
    public JTextField field2;
    public JLabel label3;
    public JTextField field3;
    public JLabel label4;
    public JTextField field4;
    public JLabel label5;
    public JTextField field5;
    public JLabel label6;
    public JTextField field6;
    public JLabel label7;
    public JTextField field7;
    public JLabel label8;
    public JTextField field8;
    public JLabel label9;
    public JTextField field9;

构造方法增加

        label2 = new JLabel("商品名称");
        GridBagConstraints gridBagConstraints3 = new GridBagConstraints();
        gridBagConstraints3.gridx = 0;
        gridBagConstraints3.gridy = 2;
        gridBagConstraints3.insets = new Insets(0,5,0,0);
        panel.add(label2,gridBagConstraints3);
        field2 = new JTextField();
        field2.setEditable(false);
        GridBagConstraints gridBagConstraints4 = new GridBagConstraints();
        gridBagConstraints4.gridx = 1;
        gridBagConstraints4.gridy = 2;
        gridBagConstraints4.insets = new Insets(0,0,0,5);
        gridBagConstraints4.weightx = 1.0;
        gridBagConstraints4.fill = GridBagConstraints.HORIZONTAL;
        panel.add(field2,gridBagConstraints4);

        GridBagConstraints gridBagConstraints5= new GridBagConstraints();
        gridBagConstraints5.gridx=0;
        gridBagConstraints5.gridy=3;
        gridBagConstraints5.insets=new Insets(0, 5, 0, 0);
        label3=new JLabel("商品厂家");
        panel.add(label3, gridBagConstraints5);
        GridBagConstraints gridBagConstraints6= new GridBagConstraints();
        gridBagConstraints6.gridx=1;
        gridBagConstraints6.gridy=3;
        gridBagConstraints6.insets=new Insets(0, 0, 0, 5);
        gridBagConstraints6.weightx=1.0;
        gridBagConstraints6.fill=GridBagConstraints.HORIZONTAL;
        field3=new JTextField();
        field3.setEditable(false);
        panel.add(field3, gridBagConstraints6);

        GridBagConstraints gridBagConstraints7= new GridBagConstraints();
        gridBagConstraints7.gridx=0;
        gridBagConstraints7.gridy=4;
        gridBagConstraints7.insets=new Insets(0, 5, 0, 0);
        label4=new JLabel("价格");
        panel.add(label4, gridBagConstraints7);
        GridBagConstraints gridBagConstraints8= new GridBagConstraints();
        gridBagConstraints8.gridx=1;
        gridBagConstraints8.gridy=4;
        gridBagConstraints8.insets=new Insets(0, 0, 0, 5);
        gridBagConstraints8.weightx=1.0;
        gridBagConstraints8.fill=GridBagConstraints.HORIZONTAL;
        field4=new JTextField();
        field4.setEditable(false);
        panel.add(field4, gridBagConstraints8);

        GridBagConstraints gridBagConstraints9= new GridBagConstraints();
        gridBagConstraints9.gridx=0;
        gridBagConstraints9.gridy=5;
        gridBagConstraints9.insets=new Insets(0, 5, 0, 0);
        label5=new JLabel("数量");
        panel.add(label5, gridBagConstraints9);
        GridBagConstraints gridBagConstraints10=new GridBagConstraints();
        gridBagConstraints10.gridx=1;
        gridBagConstraints10.gridy=5;
        gridBagConstraints10.insets=new Insets(0, 0, 0, 5);
        gridBagConstraints10.weightx=1.0;
        gridBagConstraints10.fill=GridBagConstraints.HORIZONTAL;
        field5=new JTextField();
        field5.setEditable(false);
        panel.add(field5, gridBagConstraints10);

        GridBagConstraints gridBagConstraints11= new GridBagConstraints();
        gridBagConstraints11.gridx=0;
        gridBagConstraints11.gridy=6;
        gridBagConstraints11.insets=new Insets(0, 5, 0, 0);
        label6=new JLabel("开销&收益");
        panel.add(label6, gridBagConstraints11);
        GridBagConstraints gridBagConstraints12= new GridBagConstraints();
        gridBagConstraints12.gridx=1;
        gridBagConstraints12.gridy=6;
        gridBagConstraints12.insets=new Insets(0, 0, 0, 5);
        gridBagConstraints12.weightx=1.0;
        gridBagConstraints12.fill=GridBagConstraints.HORIZONTAL;
        field6=new JTextField();
        field6.setEditable(false);
        panel.add(field6, gridBagConstraints12);

        GridBagConstraints gridBagConstraints13=new GridBagConstraints();
        gridBagConstraints13.gridx=0;
        gridBagConstraints13.gridy=7;
        gridBagConstraints13.insets=new Insets(0, 5, 0, 0);
        label7=new JLabel("货款余额");
        panel.add(label7, gridBagConstraints13);
        GridBagConstraints gridBagConstraints14= new GridBagConstraints();
        gridBagConstraints14.gridx=1;
        gridBagConstraints14.gridy=7;
        gridBagConstraints14.insets=new Insets(0, 0, 0, 5);
        gridBagConstraints14.weightx=1.0;
        gridBagConstraints14.fill=GridBagConstraints.HORIZONTAL;
        field7=new JTextField();
        field7.setEditable(false);
        panel.add(field7, gridBagConstraints14);

        GridBagConstraints gridBagConstraints15= new GridBagConstraints();
        gridBagConstraints15.gridx=0;
        gridBagConstraints15.gridy=8;
        gridBagConstraints15.insets=new Insets(0, 5, 0, 0);
        label8=new JLabel("经办人");
        panel.add(label8, gridBagConstraints15);
        GridBagConstraints gridBagConstraints16= new GridBagConstraints();
        gridBagConstraints16.gridx=1;
        gridBagConstraints16.gridy=8;
        gridBagConstraints16.insets=new Insets(0, 0, 0, 5);
        gridBagConstraints16.weightx=1.0;
        gridBagConstraints16.fill=GridBagConstraints.HORIZONTAL;
        field8=new JTextField();
        field8.setEditable(false);
        panel.add(field8, gridBagConstraints16);

        GridBagConstraints gridBagConstraints17= new GridBagConstraints();
        gridBagConstraints17.gridx=0;
        gridBagConstraints17.gridy=9;
        gridBagConstraints17.insets=new Insets(0, 5, 0, 0);
        label9=new JLabel("日期");
        panel.add(label9, gridBagConstraints17);
        GridBagConstraints gridBagConstraints18= new GridBagConstraints();
        gridBagConstraints18.gridx=1;
        gridBagConstraints18.gridy=9;
        gridBagConstraints18.insets=new Insets(0, 0, 0, 5);
        gridBagConstraints18.weightx=1.0;
        gridBagConstraints18.fill=GridBagConstraints.HORIZONTAL;
        field9=new JTextField();
        field9.setEditable(false);
        panel.add(field9, gridBagConstraints18);

点击按钮下拉框出现进货数据文件的订单。

构造方法增加

先判断文件是否存在，不存在则返回

注意先清除上次的查询订单。否则会重复订单。

button1.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                box1.removeAllItems();
                try{
                    File file = new File("E:\大二\下\JAVA\JAVA课程\专题训练\超市管理系统\sava_date.txt");
                    if(!file.exists()){
                        JOptionPane.showMessageDialog(null,"文件不存在");
                        return;
                    }

             

 使用高级流将文件的内容保存到集合。

       FileReader fr = new FileReader(file);
                    BufferedReader br = new BufferedReader(fr);
                    List list = new ArrayList();
                    String str;
                    while ((str = br.readLine())!=null){
                        list.add(str);
                    }
                  

将集合中“单号：”后的内容添加到下拉框内。

  int line = list.size();
                    for (int i = 0;i<=line-1;i++){
                        String iStr = list.get(i);
                        int start1 = iStr.indexOf("单号");
                        int end1 = iStr.indexOf(",");
                        String value1 = iStr.substring(start1+3,end1);
                        box1.addItem(value1);
                    }
                }catch (Exception e1){
                    e1.printStackTrace();
                }
            }
        });

为下拉框的Item增加点击事件，点击某订单后，自动输入到输入框。

构造方法增加

将保存订单的文件中的所有订单保存到集合中。

 box1.addItemListener(new ItemListener() {
            @Override
            public void itemStateChanged(ItemEvent e) {
                try{
                    File file = new File("E:\大二\下\JAVA\JAVA课程\专题训练\超市管理系统\sava_date.txt");
                    FileReader fr = new FileReader(file);
                    BufferedReader br = new BufferedReader(fr);
                    List list = new ArrayList();
                    String str;
                    while ((str = br.readLine())!=null){
                        list.add(str);
                    }
                   

getItemCount（）方法得到下拉框Item的数量，getSelectedIndex（）方法得到下拉列表中的选择的编号。

截取字符串中的相应内容并在输入框中显示。

 for (int i = 0;i