在Jcombobox中，当我键入一些字母说'（'j'）时，默认情况下会聚焦以'j'开头的第一个项目。但是相同的逻辑不适用于许多字母（例如'ji'）。以这样的方式使它成为可能当我输入'ji'时它应该集中在以'ji'开头的第一个项目上等等？
答案 0 :(得分：1)
在Jcombobox中，当我输入一些字母说（'j'）时，第一个项目就是 以'j'开头将默认聚焦。但相同的逻辑不是 适用于许多字母（比如'ji'）。如何使它成为可能 当我输入'ji'时，它应该集中在第一个项目上 以'ji'开头等等。
答案 1 :(得分：0)
在子类JComboBox中实现KeyListener并搜索JCombobox元素。
答案 2 :(得分：0)
我不喜欢发布大量内容，但这是我多年前采用的源代码（不记得在哪里）并修复了一些问题以使其正常工作。
用法：
String[] aItems = new String[] {"Ester", "Jordi", "Jordina", "Jorge", "Sergi"};
JAutoCompleteComboBox cboxInputModelNumber = new JAutoCompleteComboBox();
for(nItem = 0;nItem < lItems.size();nItem++)
{
aItems[nItem] = lItems.get(nItem).getNumber();
}
cboxInputModelNumber.getCompleter().setItems(lItems.toArray());
<强> JAutoCompleteComboBox.java
import java.util.List;
import java.util.Vector;
import javax.swing.ComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JTextField;
/**
*
* @author Improved by Alexandre Lavoie
*
* Source : http://www.java2s.com/Code/Java/Swing-Components/AutocompleteComboBox.htm
*/
public class JAutoCompleteComboBox extends JComboBox
{
private AutoCompleter completer;
public JAutoCompleteComboBox()
{
super();
addCompleter();
}
public JAutoCompleteComboBox(ComboBoxModel cm)
{
super(cm);
addCompleter();
}
public JAutoCompleteComboBox(Object[] items)
{
super(items);
addCompleter();
}
public JAutoCompleteComboBox(List v)
{
super((Vector) v);
addCompleter();
}
private void addCompleter()
{
setEditable(true);
completer = new AutoCompleter(this);
}
public void autoComplete(String str)
{
this.completer.autoComplete(str,str.length());
}
public String getText()
{
return ((JTextField) getEditor().getEditorComponent()).getText();
}
public void setText(String text)
{
((JTextField) getEditor().getEditorComponent()).setText(text);
}
public boolean containsItem(String itemString)
{
for(int i = 0; i < this.getModel().getSize(); i++)
{
String _item = "" + this.getModel().getElementAt(i);
if(_item.equals(itemString))
{
return true;
}
}
return false;
}
public AutoCompleter getCompleter()
{
return completer;
}
}
<强> AutoCompleter.java
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.List;
import java.util.Vector;
import javax.swing.ComboBoxModel;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JTextField;
/**
*
* @author Improved by Alexandre Lavoie
*
* Source : http://jwms-lqik2004.googlecode.com/svn/jwms_linux_eclipse/src/com/res0w/jwms/method/AutoCompleter.java
*/
public class AutoCompleter implements KeyListener, ItemListener
{
private JComboBox m_oParent = null;
private JTextField m_oEditor = null;
private ComboBoxModel m_oModel = null;
private Object[] items;
public AutoCompleter(JComboBox comboBox)
{
m_oParent = comboBox;
m_oEditor = (JTextField) comboBox.getEditor().getEditorComponent();
m_oEditor.addKeyListener(this);
m_oModel = comboBox.getModel();
m_oParent.addItemListener(this);
}
public void keyTyped(KeyEvent e)
{
}
public void keyPressed(KeyEvent e)
{
}
public void keyReleased(KeyEvent e)
{
char ch = e.getKeyChar();
// TODO : Maybe catch keys that won't update the content here
{
int caretPosition = m_oEditor.getCaretPosition();
String str = m_oEditor.getText();
if(str.length() == 0)
{
m_oParent.setPopupVisible(false);
return;
}
else
{
autoComplete(str,caretPosition);
}
}
}
/**
* ×Ô¶¯Íê³É¡£¸ù¾ÝÊäÈëµÄÄÚÈÝ£¬ÔÚÁбíÖÐÕÒµ½ÏàËƵÄÏîÄ¿.
*/
protected void autoComplete(String strf, int caretPosition)
{
Object[] opts;
opts = getMatchingOptions(strf.substring(0,caretPosition));
if(m_oParent != null)
{
m_oModel = new DefaultComboBoxModel(opts);
m_oParent.setModel(m_oModel);
}
if(opts.length > 0)
{
m_oEditor.setCaretPosition(caretPosition);
m_oEditor.setText(strf.substring(0,caretPosition));
if(m_oParent != null)
{
try
{
m_oParent.showPopup();
}
catch(Exception ex)
{
ex.printStackTrace();
}
}
}
else
{
m_oEditor.setText(strf);
}
}
/**
*
* ÕÒµ½ÏàËƵÄÏîÄ¿, ²¢ÇÒ½«Ö®ÅÅÁе½Êý×éµÄ×îÇ°Ãæ¡£
* @param str
* @return ·µ»ØËùÓÐÏîÄ¿µÄÁÐ±í¡£
*/
protected Object[] getMatchingOptions(String str)
{
List v = new Vector();
for(int k = 0; k < items.length; k++)
{
Object itemObj = items[k];
if(itemObj != null)
{
String item = itemObj.toString();
if(KMPAlgorithm.kmp(item,str))
{
v.add(items[k]);
}
}
}
return v.toArray();
}
protected Object[] getMatchingOptionsDel(String str)
{
List v = new Vector();
for(int k = 0; k < items.length; k++)
{
Object itemObj = items[k];
if(itemObj != null)
{
String item = itemObj.toString().toLowerCase();
if(KMPAlgorithm.kmp(item, str))
{
v.add(items[k]);
}
}
}
return v.toArray();
}
public void itemStateChanged(ItemEvent event)
{
if (event.getStateChange() == ItemEvent.SELECTED)
{
int caretPosition = m_oEditor.getCaretPosition();
if(caretPosition != -1)
{
try
{
m_oEditor.moveCaretPosition(caretPosition);
}
catch(IllegalArgumentException ex)
{
ex.printStackTrace();
}
}
}
}
public void setItems(Object[] x)
{
items = x;
}
}
<强> KMPAlgorithm.java
/**
*
* @author Alexandre Lavoie
*
* Source : http://jwms-lqik2004.googlecode.com/svn/jwms_linux_eclipse/src/com/res0w/jwms/method/KMPAlgorith.java
*/
public class KMPAlgorithm {
public static boolean kmp(String target, String pattern) {
/*int pLen = pattern.length();
int tLen = target.length();
//the fail function
int failFunc[] = new int[pLen];
failFunc[0] = -1;
//build fail function
for (int i = 1; i < pLen; i++) {
int j = failFunc[i - 1];
while (pattern.charAt(i) != pattern.charAt(j + 1) && j >= 0) {
//recursion
j = failFunc[j];
}
if (pattern.charAt(i) == pattern.charAt(j + 1)) {
failFunc[i] = j + 1;
} else {
failFunc[i] = -1;
}
}
int pPos = 0, tPos = 0;
while (tPos < tLen && pPos < pLen) {
if (target.charAt(tPos) == pattern.charAt(pPos)) {
//match ,then do forward
tPos++;
pPos++;
} else if (pPos == 0) {
//target go forward
tPos++;
} else {
//target postion don't change,pattern go back
pPos = failFunc[pPos - 1] + 1;
}
}
if (pPos < pLen) {
return false;
} else {
return true;
}*/
return target.toLowerCase().startsWith(pattern.toLowerCase());
}
}
答案 3 :(得分：0)