每次按下按钮时向ArrayList <number>添加值</number>

时间:2012-05-04 02:40:57

标签: java arraylist actionlistener

这是我在这里发表的第一篇文章,希望我能说得对!

我做了什么我创建了一个带有JButtons的NxN板,指示从[0,0]到[9,9]的坐标。 每次单击一个按钮时,控制台会显示坐标,我尝试做的是将这些坐标保存在一个ArrayList中,按下另一个窗口中的第二个按钮即可显示...没有什么花哨的,对不起,只是绕着我的头基本概念......

问题是我无法将值保存到ArrayList中,一旦按下第二个按钮,我就无法调用它... 附上我的课程代码......每个代码都在不同的文件中。

Board.java

public class Board{

public Board(){

    JFrame win = new JFrame ();
    GridLayout layout = new GridLayout(10, 10);
    win.setLayout(layout);
    for (int row1 = 0; row1 < 10 ; row1 = row1+1){
        for (int col1 = 0; col1 < 10; col1 = col1+1){
            JPanel jp = new JPanel();
            JButton jb = new JButton("[" + row1 + "," + col1 + "]");
            jb.addActionListener(new ButtonEventHandler(row1, col1));
            jp.add(jb);
            win.add(jp);
        }
        win.setVisible(true);
        win.pack();
}

    JFrame win2 = new JFrame("Stored values");
    win2.setVisible(true);
    JPanel jp2 = new JPanel();
    win2.add(jp2);
    JButton jb2 = new JButton("Check Log");
    jb2.addActionListener(new Position(win2, jb2));
    jp2.add(jb2);
    win2.pack();
}}

ButtonEventHandler.java

public class ButtonEventHandler implements ActionListener {


private int _row1;
private int _col1;
private ArrayList<Number> _list;


public ButtonEventHandler(int row1, int col1){

    _row1 = row1;
    _col1 = col1;
    _list = new ArrayList<Number>();
}

@Override
public void actionPerformed(ActionEvent e) {
    System.out.println("Position: " + _row1 + ", " + _col1);
    _list.add(_row1);
    _list.add(_col1);
}

public ArrayList<Number> getList(){

    return _list;
}}

Position.java

public class Position implements ActionListener  {

private JFrame _win2;

private JButton _jb2;
private int _row1;
private int _col1;
private ArrayList<Number> _list;

private ButtonEventHandler beh = new ButtonEventHandler(_row1, _col1);


public Position(JFrame win2, JButton jb2){
    _win2 = win2;
    _jb2 = jb2;     
}

@Override
public void actionPerformed(ActionEvent e) {

    System.out.println(beh.getList());      
}
}

非常感谢你的帮助!!

的Seb

2 个答案:

答案 0 :(得分:1)

代码中的问题是您没有一个数组列表:您有许多数组列表。每个按钮处理程序都有自己的!

你应该创建一个数组列表,并通过将它传递给它们的构造函数在所有处理程序中共享它。

public Position(JFrame win2, JButton jb2, AttayList<Number> list){
    _win2 = win2;
    _jb2 = jb2;
    _list = list;
}

public ButtonEventHandler(int row1, int col1, AttayList<Number> list) {
    _row1 = row1;
    _col1 = col1;
    _list = list;
}

public Board(){
    JFrame win = new JFrame ();
    GridLayout layout = new GridLayout(10, 10);
    win.setLayout(layout);
    ArrayList myList = new ArrayList<Number>();
    // In the code below, use myList as the last parameter to the constructors of ButtonEventHandler and Position
    ...

}

答案 1 :(得分:0)

好吧,我让它工作了:))

我按照建议更改了构造函数,在位置类中我删除了

private ButtonEventHandler beh = new ButtonEventHandler(_row1, _col1, _list);

并将ActionPerformed更改为:

@Override
public void actionPerformed(ActionEvent e) {
    System.out.println(beh.getList()); //previous code, changed with the one below
    System.out.println(_list);
}

通过这种方式我不再需要 Board 类中的getList方法了!

感谢您的帮助!!