正如标题所示，我正在创建一个自定义的JComboBox，当我编写popup.hide（）时，自定义的BasicComboPopup不会隐藏;另外，如果你们知道一个更简单的方法来制作一个JComboBox，它在主要组件中显示缩写值，但弹出窗口中的未缩写内容，我都是耳朵。这是我的代码：
import javax.swing.JComboBox;
import java.awt.event.MouseEvent;
import java.awt.event.MouseAdapter;
import javax.swing.JFrame;
import java.awt.GridBagLayout;
import java.awt.Component;
import java.awt.Container;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JPopupMenu;
import javax.swing.plaf.basic.BasicComboPopup;
class ChangingCombos extends JFrame
{
String[] abbrStr = new String[]{"--","TF","FF","SP"};
String[] longStr = new String[]{"-Select One-","Thermo Film","Fashion Film","Specialty"};
AbbreviatedComboBox<String> box = new AbbreviatedComboBox<String>(longStr,abbrStr);
public ChangingCombos()
{
setLayout(new GridBagLayout());
add(box);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocation(300,300);
pack();
setVisible(true);
}
public static void main(String[]args)
{
new ChangingCombos();
}
class AbbreviatedComboBox<E> extends JComboBox<E>
{
E[] items = null;
E[] abbreviations = null;
BasicComboPopup popup = null;
JComboBox self = this;
JComboBox<E> abstractBox;
public AbbreviatedComboBox(E[] items, E[] abbreviations)
{
super(abbreviations);
this.items = items;
this.abbreviations = abbreviations;
abstractBox = new JComboBox<E>(items);
popup = new BasicComboPopup(abstractBox);
addCustomMouseListener(this);
for(Component c: GUIUtilities.getAllSubcomponentsOf(this))addCustomMouseListener(c);
}
private void addCustomMouseListener(Component c)
{
c.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
System.out.println("ohp");
if(!popup.isVisible())
{
popup.show(self,0,self.getHeight());
}
else popup.hide();
}
});
}
}
}
...另外，为了解释GUIUtilities，它是另一个自定义类，方法getAllSubcomponentsOf(Container c)递归地返回所述容器中包含的所有组件。这是我访问JComboBox上的小箭头按钮的快捷方式。看起来它可能会在向同一个对象添加多个侦听器时产生问题，但它只会迭代一次该操作，正如System.out.println("ohp")每次点击仅打印一次所证实的那样。
修改：setVisible(false)不起作用。我引用的隐藏方法是ComboPopup.hide();它没有被弃用。当我执行abstractBox.hidePopup()时，它不执行任何操作，因为abstractBox未在屏幕上显示，并且从未打算过。只是它的弹出窗口。继续尝试。
答案 0 :(得分：1)
制作JComboBox的简单方法，在主要组件中显示缩写值，但弹出窗口中未缩写的内容
您将自定义对象存储在包含两个属性的ComboBoxModel中：
然后，您可以使用组合框的自定义渲染器来显示描述值。
查看ComboBox With Custom Renderer以获取此方法的更多信息和代码示例。
您还可以查看Combo Box Prompt，它允许您在不将项目存储在ComboBoxModel中的情况下提示输入值。您需要将此解决方案合并到上面示例中的渲染器中。
编辑：
也许我误解了你的要求。下面是一个简单的示例，它对下拉列表的呈现方式与组合框中的显示不同：
import java.awt.*;
import javax.swing.*;
import javax.swing.plaf.basic.*;
public class ComboBoxRenderer extends JPanel
{
public ComboBoxRenderer()
{
String[] items = { "Red", "Green", "Blue" };
JComboBox<String> comboBox = new JComboBox<String>( items );
comboBox.setSelectedIndex(-1);
comboBox.setPrototypeDisplayValue( "Select Color" );
comboBox.setRenderer( new MyRenderer() );
add(comboBox, BorderLayout.NORTH );
}
class MyRenderer extends BasicComboBoxRenderer
{
public Component getListCellRendererComponent(
JList list, Object value, int index, boolean isSelected, boolean cellHasFocus)
{
super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
if (value == null)
value = "Select Color";
if (index == -1 && value != null)
{
setText(value.toString());
}
else
setText(index + " : " + value);
return this;
}
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame("SSCCE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new ComboBoxRenderer());
frame.setLocationByPlatform( true );
frame.pack();
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
}
}
答案 1 :(得分：0)
尝试使用popup.hidePopup();我认为.hide();已被弃用。
检查this以获取有关当前方法的更多详细信息。
并且this说明为什么旧的不推荐使用。
还有另一种方法。你可以拨打popup.setVisible(false);
答案 2 :(得分：0)
这是我最终使用的结果。
import javax.swing.border.LineBorder;
import java.awt.Dimension;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.JComboBox;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.Component;
import javax.swing.JButton;
import javax.swing.plaf.basic.BasicComboPopup;
class AbbreviatedComboBox<E> extends JComboBox<E> implements MouseListener, ItemListener
{
AbbreviatedComboBox<E> self = this;
E[] items = null;
E[] abbreviations = null;
JComboBox<E> abstractBox = null;
BasicComboPopup popup = null;
JButton comboBoxButton = null;
int maximumRowCount = 0;
public AbbreviatedComboBox(E[] items, E[] abbreviations)
{
super(abbreviations);
this.items = items;
this.abbreviations = abbreviations;
abstractBox = new JComboBox<E>(items);
new JComboBoxRowCountRetreival();
popup = new BasicComboPopup(abstractBox);
for(Component c: getComponents())if(c instanceof JButton)comboBoxButton = (JButton)c;
for(MouseListener l: getMouseListeners())removeMouseListener(l);
for(MouseListener l: comboBoxButton.getMouseListeners())comboBoxButton.removeMouseListener(l);
addMouseListener(this);
comboBoxButton.addMouseListener(this);
abstractBox.addItemListener(this);
popup.setPreferredSize(new Dimension(popup.getPreferredSize().width,popup.getPreferredSize().height/maximumRowCount*items.length+popup.getMargin().top+popup.getMargin().bottom+(((LineBorder)popup.getBorder()).getThickness()*2)));
popup.addMouseListener(this);
}
public void itemStateChanged(ItemEvent e)
{
for(int i = 0; i < items.length; i++)if(items[i].equals(e.getItem()))setSelectedIndex(i);
popup.hide();
}
public void mousePressed(MouseEvent e)
{
requestFocusInWindow();
if(!popup.isVisible())
{
popup.show(this,0,getHeight());
}
else
{
popup.hide();
}
}
public void mouseReleased(MouseEvent e){}
public void mouseClicked(MouseEvent e){}
public void mouseEntered(MouseEvent e){}
public void mouseExited(MouseEvent e){}
class JComboBoxRowCountRetreival extends JComboBox
{
public JComboBoxRowCountRetreival()
{
super();
self.maximumRowCount = super.maximumRowCount;
}
}
}