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我正在使用Metal L & F.我想制作一个JComboBox，它只有1个像素边框。这不是问题，只要cb是即可编辑。这对应于名为“可编辑”的图片中的第一个cb。不可编辑JComboBox边框
cb.setEditable(true);
((JTextComponent) (cb.getEditor().getEditorComponent())).setBorder(BorderFactory.createMatteBorder(1, 1, 1, 0, COLOR));
但是当我做cb.setEditable（假），额外的边界框内出现（换成红色的图片“下拉”，你看到原来的颜色在图片命名为“固定” ）。尽管我试图设置边框，并且我也尝试使用自己的CellRenderer，但边框仍然被绘制。在我看来，不需要的边界不是来自CellRenderer。当我尝试从cb本身操作边框（请参阅注释//）时，它只会添加/删除额外的外边框。 editorComponent似乎也不对我负责。
cb.setRenderer(new CbCellRenderer());
//cb.setBorder(BorderFactory.createMatteBorder(1, 1, 1, 1, COLOR));
//cb.setBorder(BorderFactory.createEmptyBorder());
class CbCellRenderer implements ListCellRenderer {
protected DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer();
@Override
public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
JLabel renderer = (JLabel) defaultRenderer.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
renderer.setBorder(BorderFactory.createEmptyBorder());
return renderer;
}
}
我也尝试了一些UI变量，如下面的那些，而不影响这个边界。
UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
UIManager.put("ComboBox.selectionForeground", Color.green);
UIManager.put("ComboBox.disabledBackground", Color.green);
...
图片：http://upload.mtmayr.com/dropdown_frame.png（链接断开）
测试完整代码：
import java.awt.*;
import java.util.Vector;
import javax.swing.*;
import javax.swing.plaf.basic.BasicComboPopup;
public class ComboTest {
private Vector<String> listSomeString = new Vector<String>();
private JComboBox editableComboBox = new JComboBox(listSomeString);
private JComboBox nonEditableComboBox = new JComboBox(listSomeString);
private JFrame frame;
public final static Color COLOR_BORDER = new Color(122, 138, 153);
public ComboTest() {
listSomeString.add("row 1");
listSomeString.add("row 2");
listSomeString.add("row 3");
listSomeString.add("row 4");
editableComboBox.setEditable(true);
editableComboBox.setBackground(Color.white);
Object child = editableComboBox.getAccessibleContext().getAccessibleChild(0);
BasicComboPopup popup = (BasicComboPopup) child;
JList list = popup.getList();
list.setBackground(Color.white);
list.setSelectionBackground(Color.red);
JTextField tf = ((JTextField) editableComboBox.getEditor().getEditorComponent());
tf.setBorder(BorderFactory.createMatteBorder(1, 1, 1, 0, COLOR_BORDER));
nonEditableComboBox.setEditable(false);
nonEditableComboBox.setBorder(BorderFactory.createEmptyBorder());
nonEditableComboBox.setBackground(Color.white);
Object childNonEditable = nonEditableComboBox.getAccessibleContext().getAccessibleChild(0);
BasicComboPopup popupNonEditable = (BasicComboPopup) childNonEditable;
JList listNonEditable = popupNonEditable.getList();
listNonEditable.setBackground(Color.white);
listNonEditable.setSelectionBackground(Color.red);
frame = new JFrame();
frame.setLayout(new GridLayout(0, 1, 10, 10));
frame.add(editableComboBox);
frame.add(nonEditableComboBox);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocation(100, 100);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
ComboTest ct = new ComboTest();
}
});
}
}
类似过帐： [LINK1]（http://stackoverflow.com/questions/10569759/ border-editor-when-rendering-item-in-jcombobox-and-editable-false） [link2]（http://stackoverflow.com/questions/10169022/jcombobox-does-not-behave-same-as-jtextfield我怎么可以有它看起来相似） [link3]（http://stackoverflow.com/questions/9322903/how-do-you-change-border-of-the-pop-up-section-of-a-jcombobox） [link4]（http： //www.stackoverflow.com/questions/776893/remove-border-from-jcombobox） – mtmayr 2013-03-25 17:54:34