java - 将数组列表中的键放到 jbutton 上？还有如何实现 KeyListener

Question

我需要让 JButton 显示字母表中的随机键。这是到目前为止我的代码:

public void actionPerformed (ActionEvent e) {    
    Random r = new Random();
    char c = (char)(r.nextInt(26) + 'a');
    String[] myStringArray = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
    JButton b = new JButton(myStringArray[c]);
    JButton b2 = new JButton(myStringArray[c]);
    JButton b3 = new JButton(myStringArray[c]);
    JButton b4 = new JButton("");
}

但我收到错误。我究竟做错了什么？另外，我想实现一个 KeyListener，这样当 JButton 上显示的随机键按下时，它将使该 jbutton 消失并在顶部弹出一个新的按钮。感谢您的帮助。

Answer 1

• 我认为您不应该每次调用时都创建 Random 对象。
• c 用作数组索引，因此它应该是 int，而不是 char。另外，请勿将 'a' 添加到 c，因为它只会导致超出范围的异常。

试试这个(未测试):

private Random r = new Random(); // a field of this class

public void actionPerformed (ActionEvent e) {
    int c = r.nextInt(26);
    String[] myStringArray = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
    JButton b = new JButton(myStringArray[c]);
    JButton b2 = new JButton(myStringArray[c]);
    JButton b3 = new JButton(myStringArray[c]);
    JButton b4 = new JButton("");
}