Swing – 简单入门

JFrame j = new JFrame();j.setSize(100,400);//  JFrame容器内元素 流式布局j.setLayout(new FlowLayout());// 添加十个按钮for(int i = 0; i < 10; i++) {    j.add(new JButton(i + ""));}j.setVisible(true);

3.5.3 边界布局 – BorderLayout

1. 分成5个区域：north、south、west、east、center

2. 一个区域只能放一个组件、后者覆盖前者

JFrame j = new JFrame();
j.setSize(300, 300);
j.setLayout(new BorderLayout());

j.add(new JButton(1 + ""), BorderLayout.NORTH);
j.add(new JButton("覆盖1"), BorderLayout.NORTH);
j.add(new JButton(2 + ""), BorderLayout.SOUTH);
j.add(new JButton(3 + ""), BorderLayout.WEST);
j.add(new JButton(4 + ""), BorderLayout.EAST);
j.add(new JButton(5 + ""), BorderLayout.CENTER);

j.setVisible(true);

3.5.4 网格布局 – GridLayout

设定整个窗口的最多行、列 – 容器内元素的宽高自适应

程序尽可能的填满整个屏幕

JFrame j = new JFrame();
j.setSize(300, 300);

// 网格布局
Container c = j.getContentPane();
c.setLayout(new GridLayout(4,4,10,20));

// 添加元素
for(int i = 0; i< 20; i++) {
    c.add(new JButton(i + ""));
}

/*  -- 只添加5个元素，则如下面第二张图
for(int i = 0; i < 5; i++) {
    c.add(new JButton(i + ""));
}*/


j.setVisible(true);

3.5.5 卡片布局 – CardLayout

    // 1. 设置JFrame内的元素未 边界布局
JFrame j = new JFrame();
j.setSize(500, 500);
j.setLayout(new BorderLayout());


// 2. 将center位置的panel 添加两张卡片 card1、card2
CardLayout cardLayout = new CardLayout();
JPanel panel = new JPanel();
panel.setBackground(Color.CYAN);
JPanel card1 = new JPanel();
card1.setBackground(Color.red);
JPanel card2 = new JPanel();
card2.setBackground(Color.green);

panel.setLayout(cardLayout);
panel.add(card1, "card1");
panel.add(card2, "card2");


// 3. 将wedt位置的panel2 添加两个按钮，并且定义他们的点击事件
JPanel panel2 = new JPanel();
panel2.setBackground(Color.blue);
JButton btn1 = new JButton("卡片1");
JButton btn2 = new JButton("卡片2");
btn1.addActionListener(new ActionListener() {

    @Override
    public void actionPerformed(ActionEvent e) {
        //cardLayout.show(panel, "card1");
        cardLayout.first(panel);
    }

});
btn2.addActionListener(new ActionListener() {

    @Override
    public void actionPerformed(ActionEvent e) {
        //cardLayout.show(panel, "card2");
        cardLayout.last(panel);
    }

});
panel2.add(btn1);
panel2.add(btn2);


j.add(panel, BorderLayout.CENTER);
j.add(panel2, BorderLayout.WEST);

j.setVisible(true);
j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

3.6 监听器

3.6.1 鼠标点击监听器

// 设置 JFrame 为 绝对定位布局
JFrame j = new JFrame();
j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
j.setLayout(null);
j.setSize(500, 500);

// 初始化jList列表框，并把其放入到  带滚动条的面板上
String[] stus = {"学生1","学生2","学生3","学生4","学生5","学生5","学生5","学生5"};
JList<String> list = new JList<String>(stus);
JScrollPane js = new JScrollPane(list);
js.setBounds(10,10,100,100);

// 添加按钮的 点击事件处理
JButton btn = new JButton("打印选中的元素");
btn.setBounds(10,120, 200,50);
btn.addActionListener(new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println(list.getSelectedValuesList());
    }

});

j.add(js);
j.getContentPane().add(btn);
j.setVisible(true);

3.6.2 焦点监听器

public class JFrame2 extends JFrame {
    JTextField input = new JTextField();
    JTextField input2 = new JTextField();


    class MyListener implements FocusListener {

        @Override
        public void focusGained(FocusEvent e) {
            Object o  =e.getSource();
            if(o == input) {
                System.out.println("input失去焦点");
            }else if( o == input2 ){
                System.out.println("iput2失去焦点");
            }
        }

        @Override
        public void focusLost(FocusEvent e) {
            Object o  =e.getSource();
            if(o == input) {
                System.out.println("input获取焦点");
            }else if( o == input2 ){
                System.out.println("iput2获取焦点");
            }
        }

    }

    JFrame2() {
        JFrame j = new JFrame();
        j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        j.setLayout(new FlowLayout());
        j.setSize(250, 250);


        input.setColumns(20);
        input2.setColumns(20);

        FocusListener list = new MyListener();
        input.addFocusListener(list);
        input2.addFocusListener(list);
        j.add(input);
        j.add(input2);


        j.setVisible(true);
    }
}



// 测试 
new JFrame2();

3.6 JTable – 表格

3.6.1 表格数据的添加

  表格单行数据添加

JTable table = new JTable();

DefaultTableModel tableModel = (DefaultTableModel) table.getModel();

Vector v = new Vector()   

// 单行数据  --- 故每添加一行数据需要不断的清空v的内容
tableModel.add( v )

3.6.2 表格数据清空

JTable table = new JTable();

DefaultTableModel tableModel = (DefaultTableModel) table.getModel();

tableModel.setRowCount(0)

3.6.3 删除选中行的数据

JTable table = new JTable();

DefaultTableModel model = (DefaultTableModel) table.getModel();

Integer selectedRow = table.getSelectedRow();

model.removeRow(selectedRow);

3.7 JComboBox – 下拉列表框

3.7.1 列表框数据的添加

JComboBox jcb = new JComboBox();

// 单条记录的添加
jcb.addItem( Object o )

3.7.2 获取选中的列表框数据

JComboBox<String> jcb = new JComboBox<String>();

String str = typeNameBox.getSelectedItem();

小半

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