急!!!怎么才能调整JListCombo的下拉列表的大小,嫌分少再加.

Question

你自己写一个Renderer而后设置 Renderer 的大小就好了如： class MyCellRenderer extends JLabel implements ListCellRenderer {
     public MyCellRenderer() {
         setOpaque(true);
     }
     public Component getListCellRendererComponent(
         JList list,
         Object value,
         int index,
         boolean isSelected,
         boolean cellHasFocus)
     {
         setText(value.toString());
         setBackground(isSelected ? Color.red : Color.white);
         setForeground(isSelected ? Color.white : Color.black);
         return this;
     }
 }
////// 
JComboBox patternList = new JComboBox(patternExamples);
MyCellRenderer comboxRenderer = new MyCellRenderer();
comboxRenderer.setPreferredSize(new Dimension(600, 300));
patternList.setRenderer(comboxRenderer);
这样就好了

Answer 1

JListCombo?怎么没见过这个东西?

Answer 2

JListCombo就是类似网页里的下拉选单一样的东西可是comboxRenderer.setPreferredSize(new Dimension(600, 300));这个方法只对高度有效,我是想让它的宽度调大些,有办法吗?

Answer 3

哦,是我打错了,其实就是JComboBox

Answer 4

你是想让combox弹出来选择数据的窗口的大小和combox在界面上显示的不一样大?

Answer 5

UI ui = new UI();
        jComboBox1.setUI(ui);
        ((Popup)ui.getPopup()).setDisplaySize(100, 50);
**************
    class UI extends javax.swing.plaf.basic.BasicComboBoxUI {
        protected javax.swing.plaf.basic.ComboPopup createPopup() {
            Popup popup = new Popup( comboBox );
            popup.getAccessibleContext().setAccessibleParent(comboBox);
            return popup;
        }
        public javax.swing.plaf.basic.ComboPopup getPopup() {
            return popup;
        }
    }    class Popup extends javax.swing.plaf.basic.BasicComboPopup {
        public Popup(JComboBox combo) {
            super(combo);
        }
        public void setDisplaySize(int width, int height) {
            scroller.setSize(width, height);
            scroller.setPreferredSize(new Dimension(width, height));
        }
        public void show() {
            setListSelection(comboBox.getSelectedIndex());
            Point location = getPopupLocation();
            show( comboBox, location.x, location.y );
        }
        private void setListSelection(int selectedIndex) {
            if ( selectedIndex == -1 ) {
                list.clearSelection();
            }
            else {
                list.setSelectedIndex( selectedIndex );
                list.ensureIndexIsVisible( selectedIndex );
            }
        }        private Point getPopupLocation() {
            Dimension popupSize = comboBox.getSize();
            Insets insets = getInsets();            // reduce the width of the scrollpane by the insets so that the popup
            // is the same width as the combo box.
            popupSize.setSize(popupSize.width - (insets.right + insets.left),
                              getPopupHeightForRowCount( comboBox.getMaximumRowCount()));
            Rectangle popupBounds = computePopupBounds( 0, comboBox.getBounds().height,
                popupSize.width, popupSize.height);
            Dimension scrollSize = popupBounds.getSize();
            Point popupLocation = popupBounds.getLocation();//            scroller.setMaximumSize( scrollSize );
//            scroller.setPreferredSize( scrollSize );
//            scroller.setMinimumSize( scrollSize );            list.revalidate();            return popupLocation;
        }
    }

Answer 6

JComboBox的宽度好像是和嵌入到里面的字符串的长度有关系吧！——以最长的字符串为参照
你可以试一下！（CM.java）import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class CM extends JFrame
{
String []name={"张三","李四","王五","赵六"};
String []name2={"张三","李四","王五","铁木尔达达买其"};
JComboBox id1,id2;
JPanel panel;
CM()
{
id1=new JComboBox(name);
id2=new JComboBox(name2);
panel=new JPanel();
getContentPane().add(panel);

panel.add(id1);
panel.add(id2);
setSize(300,200);
setVisible(true);
}
public static void main(String args[])
{
new CM();
}
}你编译一下就知道了！

Answer 7

谢谢Acylas(Acylas) 的代码.to: VincentSailing(文森特)
你的代码是由布局来自动控制组件大小的,我用的是null加指定大小,所以不会效果,再说也不可能真的让List老长一个.