使用盒式布局实现登录界面

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/u014248473/article/details/88999920

一、写在前面

1. 使用BoxLayout布局方式，控制组件内容在水平与垂直方向居中显示；

二、代码

public class LoginFrame extends JFrame {
    private static final int LOGIN_WIDTH = 600;
    private static final int LOGIN_HEIGHT = 400;

    public LoginFrame(){
        setTitle("登录界面");

        JPanel loginPanel = new JPanel();
        loginPanel.setBackground(new Color(204, 204, 204));//#CCC
        loginPanel.setLayout(new BoxLayout(loginPanel, BoxLayout.Y_AXIS));

        JPanel vCenterPanel = new JPanel();
        vCenterPanel.setBackground(new Color(204, 204, 204));
        vCenterPanel.setLayout(new BoxLayout(vCenterPanel, BoxLayout.X_AXIS));

        JPanel hCenterPanel = new JPanel();
        hCenterPanel.setBackground(Color.WHITE);

        Box labelBox = Box.createVerticalBox();
        JLabel jLabel = new JLabel("用户名：");
        jLabel.setOpaque(true);
        jLabel.setBackground(Color.YELLOW);
        labelBox.add(jLabel);
        labelBox.add(Box.createVerticalStrut(10));
        JLabel label = new JLabel("密    码：");
        label.setOpaque(true);
        label.setBackground(Color.CYAN);
        labelBox.add(label);

        Box fieldBox = Box.createVerticalBox();
        fieldBox.add(new JTextField(15));
        fieldBox.add(Box.createVerticalStrut(10));
        fieldBox.add(new JPasswordField(15));

        Box hBox = Box.createHorizontalBox();
        hBox.add(labelBox);
        hBox.add(Box.createHorizontalStrut(15));
        hBox.add(fieldBox);

        Box vBox = Box.createVerticalBox();
        vBox.add(Box.createVerticalStrut(50));
        vBox.add(hBox);
        vBox.add(Box.createVerticalStrut(10));
        vBox.add(new JButton("登录"));

        hCenterPanel.add(vBox);

        vCenterPanel.add(Box.createHorizontalGlue());
        vCenterPanel.add(hCenterPanel);
        vCenterPanel.add(Box.createHorizontalGlue());

        loginPanel.add(Box.createVerticalGlue());
        loginPanel.add(vCenterPanel);
        loginPanel.add(Box.createVerticalGlue());

        getContentPane().add(loginPanel);

        setSize(LOGIN_WIDTH, LOGIN_HEIGHT);
        setLocation(Screen.getCenterPosition(LOGIN_WIDTH, LOGIN_HEIGHT));
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }

    public static void main(String[] args) {
        new LoginFrame();
    }
}

public class Screen {

    private int width;
    private int height;

    public Screen(){
        Toolkit toolkit = Toolkit.getDefaultToolkit();
        Dimension screenSize = toolkit.getScreenSize();
        this.width = screenSize.width;
        this.height = screenSize.height;
    }

    public static Point getCenterPosition(int width, int height){
        Screen screen = new Screen();
        int x = (screen.getWidth() - width) / 2;
        int y = (screen.getHeight() - height) / 2;
        return new Point(x, y);
    }

    public int getWidth() {
        return width;
    }

    public void setWidth(int width) {
        this.width = width;
    }

    public int getHeight() {
        return height;
    }

    public void setHeight(int height) {
        this.height = height;
    }
}

三、效果图