ot;RadioCheckNew");
aFrame.addWindowListener(
new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
aFrame.add(applet, BorderLayout.CENTER);
aFrame.setSize(300,200);
applet.init();
applet.start();
aFrame.setVisible(true);
}
} ///:~
ILCheck拥有当我们增加或者减少复选框时自动调整的优点。当然，我们对单选钮使用这种方法也同样的好。但是，它仅当我们的逻辑足以普遍的支持这种方法时才会被使用。如果声明一个确定的信号——我们将重复利用独立的接收器类，否则我们将结束一串条件语句。4. 下拉列表下拉列表在Java 1.1版中当一个选择被改变时同样使用ItemListener去告知我们：
//: ChoiceNew.java
// Drop-down lists with Java 1.1
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class ChoiceNew extends Applet {
String[] description = { "Ebullient", "Obtuse",
"Recalcitrant", "Brilliant", "Somnescent",
"Timorous", "Florid", "Putrescent" };
TextField t = new TextField(100);
Choice c = new Choice();
Button b = new Button("Add items");
int count = 0;
public void init() {
t.setEditable(false);
for(int i = 0; i < 4; i++)
c.addItem(description[count++]);
add(t);
add(c);
add(b);
c.addItemListener(new CL());
b.addActionListener(new BL());
}
class CL implements ItemListener {
public void itemStateChanged(ItemEvent e) {
t.setText("index: " + c.getSelectedIndex()
+ " " + e.toString());
}
}
class BL implements ActionListener {
public void actionPerformed(ActionEvent e) {
if(count < description.length)
c.addItem(description[count++]);
}
}
public static void main(String[] args) {
ChoiceNew applet = new ChoiceNew();
Frame aFrame = new Frame("ChoiceNew");
aFrame.addWindowListener(
new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
aFrame.add(applet, BorderLayout.CENTER);
aFrame.setSize(750,100);
applet.init();
applet.start();
aFrame.setVisible(true);
}
} ///:~
这个程序中没什么特别新颖的东西（除了Java 1.1版的UI类里少数几个值得关注的缺陷）。5. 列表我们消除了Java 1.0中List设计的一个缺陷，就是List不能像我们希望的那样工作：它会与单击在一个列表元素上发生冲突。
//: ListNew.java
// Java 1.1 Lists are easier to use
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class ListNew extends Applet {
String[] flavors = { "Chocolate", "Strawberry",
"Vanilla Fudge Swirl", "Mint Chip",
"Mocha Almond Fudge", "Rum Raisin",
"Praline Cream", "Mud Pie" };
// Show 6 items, allow multiple selection:
List lst = new List(6, true);
TextArea t = new TextArea(flavors.length, 30);
Button b = new Button("test");
int |
