Java 如何向动作侦听器提供变量?
我在类中有一个静态变量Java 如何向动作侦听器提供变量?,java,variables,visibility,actionlistener,Java,Variables,Visibility,Actionlistener,我在类中有一个静态变量partner。我想在按下单选按钮时设置这些变量的值。这是我尝试使用的代码: for (String playerName: players) { option = new JRadioButton(playerName, false); option.addActionListener(new ActionListener(){ @Override public void actionPerformed(ActionEven
partner
。我想在按下单选按钮时设置这些变量的值。这是我尝试使用的代码:
for (String playerName: players) {
option = new JRadioButton(playerName, false);
option.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent evt) {
partner = playerName;
}
});
partnerSelectionPanel.add(option);
group.add(option);
}
这里的问题是
actionPerformed
没有看到在循环中创建的变量playerName
。如何将此变量传递给actionListener?变量必须是final才能将其传递给内部类
for (final String playerName: players) {
option = new JRadioButton(playerName, false);
option.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent evt) {
partner = playerName;
}
});
partnerSelectionPanel.add(option);
group.add(option);
}
传递给内部类的局部变量必须是final。最初我认为您不能在for循环中使playerName
成为final,但事实上您可以。如果不是这样,您只需将playerName
存储在附加的final变量(final String pn=playerName
)中,并使用pn
fromactionPerformed
JButton button = new JButton("test");
button.addActionListiner(new ActionForButton("test1","test2"));
class ActionForButton implements ActionListener {
String arg,arg2;
ActionFroButton(String a,String b) {
arg = a; arg2 = b;
}
@Override
public void actionPerformed(ActionEvent e) {
Sustem.out.println(arg + "--" + arg2);
}
}