Java Swing 调整 BorderLayout.CENTER 大小

Question

如标题所说，能否重新定义Java的BorderLayout.CENTER的高度和宽度？我计划使用 Graphics2D 绘制该区域，但我并不总是提前知道它应该有多大才能容纳所有内容。

绘制类(在我的主类中声明):

@SuppressWarnings("serial")
private class Draw extends JComponent {
    public void paint(Graphics graphics) {
        Graphics2D g = (Graphics2D) graphics;
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

        Shape drawLine = new Line2D.Float(0, 0, 500, 500);

        g.setPaint(Color.BLACK);
        g.draw(drawLine);
    }
}

调用 Draw 的主构造函数:

public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 640, 480);
    setJMenuBar(getMenuBar_1());
    contentPane = new JPanel();
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    setContentPane(contentPane);
    contentPane.setLayout(new BorderLayout(0, 0));
    contentPane.add(getPanelControls(), BorderLayout.SOUTH);
    contentPane.add(getPanelInfo(), BorderLayout.EAST);
    contentPane.add(new Draw(), BorderLayout.CENTER);
}

我当前正在直接绘制到 BorderLayout.CENTER。我应该绘制到 JPanel 并使用它的 setPreferredSize() 方法吗？

Answer 1

As the title says, can I redefine the height and width of Java's BorderLayout.CENTER? I plan to use Graphics2D to draw to this area but I won't always know ahead of time how big it should be to fit everything in.

(仅回答主题)

• 覆盖其 getPreferredSize

• 那么任何大小调整都会适得其反，请在 JFrame.setVisible(true);

之前调用 JFrame.pack();

• 创建一个 JFrame 作为局部变量

编辑

<小时/>

• 覆盖paintComponent()而不是paint()，paintComponent()内的第一个代码行应该是super .paintComponent()，否则绘制累积

• Shape drawLine = new Line2D.Float(0, 0, 500, 500); 应该是 getHeight/Weight() 而不是 500 , 500