从JComboBox移除边框 [英] Remove border from JComboBox

问题描述

您知道从Java中的JComboBox删除边框的任何方法吗?我尝试以下代码

Do you know any way to remove the border from a JComboBox in Java? I try the following code

public class ComboFrame extends JFrame {
    public ComboFrame() {
        JPanel container = new JPanel();

        JComboBox cmb = new JComboBox(new String[] { "one", "two" });
        cmb.setBorder(BorderFactory.createEmptyBorder());
        container.add(cmb);

        getContentPane().add(container);
        pack();
    }
}

和

public static void main(String[] args) throws Exception {
    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            new ComboFrame().setVisible(true);
        }
    });
}

不要问为什么有人要从combobx删除边框...我想这没有太大意义，但这就是想要的样子，我真的很好奇是否可以做到.我尝试了几种技巧，但没有一个起作用.

Don't ask why would someone want to remove the border from a combobx... I guess it does not make too much sense, but this is how it's wanted, and I got really curious if it can be done. I tried several tricks, but none of them worked.

最有效的方法是更改​​用户界面

The most effective was changing the UI with

cmb.setUI(new BasicComboBoxUI());

这使边界消失了，但是改变了L& F，如果可能，我需要保留Windows L& F.

This makes the border go away, but alters the L&F, and I need to keep the Windows L&F if possible.

谢谢.

推荐答案

我做了一些研究，发现此错误

I did a bit of research and found this bug

我为自己尝试过，它似乎确实影响了边境.您可能需要自己尝试以下一个或两个代码块.

I tried it for myself and it does seem to affect the border. You might want to try one or both of the following code blocks for yourself.

for (int i = 0; i < combo.getComponentCount(); i++) 
{
    if (combo.getComponent(i) instanceof JComponent) {
        ((JComponent) combo.getComponent(i)).setBorder(new EmptyBorder(0, 0,0,0));
    }


    if (combo.getComponent(i) instanceof AbstractButton) {
        ((AbstractButton) combo.getComponent(i)).setBorderPainted(false);
    }
}

请务必注意，在错误条目的底部，您可以阅读以下内容:

It is important to note that at the bottom of the bug entry, you can read the following:

JButton保留了自己的边框，因此JComponent paintBorder()和 paintComponent()不了解JComboBox边框.

The JButton maintains it's own border so JComponent paintBorder() and paintComponent() has no awareness of the JComboBox border.

祝你好运

沙滩！

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