在不同的自定义列表中再次重用JScrollPane的问题 [英] Problem with reusing the JScrollPane again for different custom Lists
问题描述
我正在尝试创建一个JScrollPane组件,该组件可以根据所传递的字符串参数进行重用. 我已经创建了以下代码,如果我使用JFrame将JScrollPane嵌入其中,它会起作用, 但是当我尝试在创建其他JScrollPane时重用代码时,scrollPane根本不会显示. 我正在java swing项目中实现它. 请让我知道该怎么做.任何建议都将受到高度赞赏.
I am trying to create a JScrollPane component which can be reused depending upon the string parameter that is being passed.. I have created the following code, it works if I use JFrame to embed the JScrollPane inside it, but when I try to reuse the code in creating different JScrollPane the scrollPane is not displayed at all.. I am implementing it in a java swing project.. Please let me know what should be done in this..any suggestions are highly appreciated.
关于JComboBox的相同问题,它不显示...
The same problem I have with regards to the JComboBox, it doesn't display...
public class ListComponent extends JScrollPane {
private String[] selectedNames;
private String[] listNames;
private JButton submit, reset;
private JPanel subPanel = new JPanel();
private JList list;
private JScrollPane scroll;
public String getFirstSelectionInList() {
return selectedNames[0];
}
ListComponent() {
/*submit = new JButton("Submit");
reset = new JButton("Reset");*/
subPanel.setLayout(new FlowLayout());
/*subPanel.add(submit);
subPanel.add(reset);*/
}
ListComponent(String[] listNames) {
this();
/*JFrame frame = new JFrame("Creating a JList Component");*/
this.listNames = new String[listNames.length];
this.listNames = listNames;
//this.setLayout(new BorderLayout());
//this.setLayout(new ScrollPaneLayout());
JPanel panel = new JPanel();
list = new JList(listNames);
scroll = new JScrollPane(list);
scroll.setVerticalScrollBarPolicy(
JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
/*panel.add(scroll);
panel.add(subPanel,BorderLayout.SOUTH);*/
/*frame.add(panel);
frame.pack();
frame.setVisible(true);*/
this.setVisible(true);
list.addListSelectionListener(listSelectionListener);
}
ListSelectionListener listSelectionListener = new ListSelectionListener() {
public void valueChanged(ListSelectionEvent listSelectionEvent) {
boolean adjust = listSelectionEvent.getValueIsAdjusting();
//System.out.println(", Adjusting? " + adjust);
if (!adjust) {
JList list = (JList) listSelectionEvent.getSource();
int selections[] = list.getSelectedIndices();
Object selectionValues[] = list.getSelectedValues();
int n = selections.length;
selectedNames = new String[n];
for (int i = 0; i < n; i++) {
if (i == 0) {
System.out.print(" Selections: ");
}
selectedNames[i] = (String) selectionValues[i];
System.out.print(selectedNames[i]
+ "/" + selectionValues[i]);
}
}
}
};
/** @return the selectedNames */
public String[] getSelectedNames() {
return selectedNames;
}
/** @param selectedNames the selectedNames to set */
public void setSelectedNames(String[] selectedNames) {
this.selectedNames = selectedNames;
}
public static void main(String args[]) {
String subject[] = {"Math", "Computer", "Phisics", "Chemestry"};
new ListComponent(subject);
}
}
推荐答案
@camickr是正确的; JPanel
是一个更好的轻量级通用容器"成分."您可以将其他组件添加到下面示例中使用的BorderLayout
的其他区域.在事件分发线程.
@camickr is correct; JPanel
is a better "general-purpose container for lightweight components." You can add additional components to the other areas of the BorderLayout
used in the example below. It's also a good habit to build your GUI on the event dispatch thread.
import java.awt.*;
import java.util.Arrays;
import javax.swing.*;
import javax.swing.event.*;
/** @see http://stackoverflow.com/questions/4176343 */
public class ListPanel extends JPanel {
private JList list;
public ListPanel(String[] data) {
super(new BorderLayout());
list = new JList(data);
list.addListSelectionListener(new SelectionHandler());
JScrollPane jsp = new JScrollPane(list);
this.add(jsp, BorderLayout.CENTER);
}
private class SelectionHandler implements ListSelectionListener {
@Override
public void valueChanged(ListSelectionEvent e) {
if (!e.getValueIsAdjusting()) {
System.out.println(Arrays.toString(list.getSelectedValues()));
}
}
}
private void display() {
JFrame f = new JFrame("ListPanel");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(this);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
String[] data = {"Math", "Computer", "Physics", "Chemistry"};
new ListPanel(data).display();
}
});
}
}
这篇关于在不同的自定义列表中再次重用JScrollPane的问题的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!