Question

请高手帮忙解答一个Java问题

我想知道那个这段复选框程序中，最后那一句return 0是什么意思？我好像把它改成别的数字都没有什么影响啊？请高手答疑

import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;

import javax.swing.AbstractListModel;
import javax.swing.ComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.WindowConstants;

public class SelectID extends JFrame {
public static void main(String[] args) {
new SelectID();
}

JComboBox x = new JComboBox(new MyComeboBox());
JLabel t = new JLabel("please choice");

public SelectID() {
setTitle("CHOICE");
setSize(new Dimension(300, 280));
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setVisible(true);
Container a = getContentPane();
setLayout(new FlowLayout());
a.add(t);
a.add(x);

}
}

class MyComeboBox extends AbstractListModel implements ComboBoxModel {
String aa = null;
String[] liste = { "A", "B", "C", "D" };

public Object getElementAt(int index) {
return liste[index];
}

public int getSize() {
return liste.length;
}

public Object getSelectedItem() {
return aa;
}

@Override
public void setSelectedItem(Object anItem) {
aa = (String) anItem;
}

public int getindex() {
for (int i = 0; i < liste.length; i++) {
if (liste[i].equals(getSelectedItem())) {
return i;
}
break;
}

return 0;

}
}

Answer 1

getIndex 的意思就是 在一个数组里面返回一个item 的索引
如果数组里面没有这东西。就返回0

Answer 2

没找到时默认返回liste中第0个，改成几就默认返回第几个