检查单击了（多个J按钮中的）哪个J按钮

Question

我正在制作一个棋盘游戏，8X8矩阵，在一个框架中有64个JButton。到目前为止，我的代码是这样的：

public class Main {
static JFrame f  = new JFrame();;
static JButton btn;
static JButton btnTemp;


    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setLayout((new GridLayout(8,8)));//size of the board
    f.setTitle("ex");
    f.setSize(800,800);

for (int i=0;i<=7;i++)
    {
        for (int j = 0; j<=7;j++)
        {

            btn=new JButton();
            btn = new JButton(new SoliderW());  
            btn.setName("btn"+i+""+j);
            btn.setBackground(Color.BLACK); 
            btn.addActionListener(actionListener); // make a listener to the button
            f.add(btn);
            }

    }


    f.setVisible(true);

我试图告诉哪个JButoon是使用此代码单击的：

Component[] components = f.getContentPane().getComponents();


    ActionListener actionListener = new ActionListener()
    {
      @Override
        public void actionPerformed(ActionEvent e)
         {
              System.out.println("Hello");
          }
     };

       for (Component component : components)
          {
               if (component instanceof JButton)
                  {
                  ((JButton) component).addActionListener(actionListener);
                  }
          }

然而，我不知道如何辨别点击了哪个Jbutton。

Answer 1

按照MadProgrammer的建议实现MVC模式可以如下完成：
拥有一个包含视图（gui）需要的所有信息的模型
有一个使用模型显示gui的视图类
有一个控制模型和视图的控制器类

下面的mre演示了使用MVC模式来实现所需的功能。
为了方便和简单，可以将以下代码复制粘贴到一个名为Main.java的文件中并运行：

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main {

    public static void main(String[] args) {
        new Controller();
    }
}

//used listen to changes in view
interface SelectionListener{

    void selected(int row, int column);
}

/*Model contains the information for the view and information from the view
 * as well as the logic.
 * The model is independent of the user interface.
 */
class Model {

    private final String[][] soliderNames;

    Model(int size){

        soliderNames = new String[size][size];

        for (int i=0 ; i<size  ; i++)  {
            for (int j=0; j<size ; j++) {
                soliderNames[i][j] = i+"-"+j;
            }
        }
    }

    int getNunberOfRows(){
        return soliderNames.length;
    }

    int getNunberOfColumns(){
        return soliderNames[0].length;
    }

    String getName(int row, int column) {
        return soliderNames[row][column];
    }
}

/*View only contains the user interface part*/
class View{

    private final JFrame f;
    private static final int W = 50, H = 50;

    View(Model model, SelectionListener selectionListener){

        int rows = model.getNunberOfRows();
        int cols = model.getNunberOfColumns();

        JPanel view = new JPanel(new GridLayout(rows, cols));
        for (int i=0 ; i < rows ; i++)  {
            for (int j = 0 ; j < cols ; j++)    {
                int finalI =i, finalJ = j;
                JButton btn = new JButton();
                btn = new JButton("-");
                btn.setPreferredSize(new Dimension(W,H));
                btn.setBackground(Color.BLACK);
                btn.addActionListener( a -> selectionListener.selected(finalI, finalJ));
                view.add(btn);
            }
        }

        f  = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setTitle("ex");
        f.add(view);
        f.pack();
    }

    void show(){
        f.setVisible(true);
    }
}

/* The controller controls the view and model.
 * Based on the user action, the Controller calls methods in the View and Model
 * to accomplish the requested action.
 */
class Controller implements SelectionListener {

    private static final int SIZE = 8;
    private final Model model;

    Controller(){
        model = new Model(SIZE);
        View view = new View(model, this);
        view.show();
    }

    @Override
    public void selected(int row, int column) {

        System.out.print("row: "+ row + "  column: "+ column + " clicked. ");
        System.out.println("Name is "+ model.getName(row, column));
    }
}

Answer 2

您也可以在侦听器中执行此操作：

Object src = e.getSource();
if ( src instanceof JButton ) {
   System.out.println( "Button is: " + ((JButton)src).getName() );
}

但最好将所有按钮放在一个ArrayList中，然后只使用int index=list。indexOf（src）

Answer 3

让我们从静态开始，静态不是您的朋友，您应该避免使用它，尤其是当您试图跨对象边界引用实例时。

例如，使用匿名类...

btn = new JButton();
btn = new JButton(new SoliderW());
btn.setName("btn" + i + "" + j);
btn.setBackground(Color.BLACK);
btn.addActionListener(new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent evt) {
        // Do some work
    }
}); // make a listener to the button

但是，老实说，由于btn是静态，这对您没有帮助

使用actionCommand属性

ActionListener actionListener = new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent evt) {
        String command = evt.getActionCommand();
        // Do more work
    }
};

//...

for (int i = 0; i <= 7; i++) {
    for (int j = 0; j <= 7; j++) {

        btn = new JButton();
        btn = new JButton(new SoliderW());
        btn.setName("btn" + i + "" + j);
        btn.setBackground(Color.BLACK);
        // Replace the text with something that will
        // uniquely identify this button
        btn.setActionCommand("some cell identifier");
        btn.addActionListener(actionListener); // make a listener to the button
        f.add(btn);
    }

}

创建一个自定义的ActionListener，它获取所需的信息，以便更好地决定要做什么（并将其与按钮本身分离）

public class CardActionListener implements ActionListener {
    private int row, col;

    public CardActionListener(int row, int col) {
        this.row = row;
        this.col = col;
    }

    @Override
    public void actionPerformed(ActionEvent arg0) {
        // Do some work...
    }
}

//...

for (int i = 0; i <= 7; i++) {
    for (int j = 0; j <= 7; j++) {

        btn = new JButton();
        btn = new JButton(new SoliderW());
        btn.setName("btn" + i + "" + j);
        btn.setBackground(Color.BLACK);
        btn.addActionListener(new CardActionListener(i, j)); // make a listener to the button
        f.add(btn);
    }

}

我个人喜欢使用API。

这类似于最后一个建议，但创建了一个更加独立的工作单元，它与调用者分离。

public class CardAction extends AbstractAction {
    private int row, col;

    public CardAction(int row, int col) {
        this.row = row;
        this.col = col;
        putValue(Action.LARGE_ICON_KEY, new SoliderW());
    }

    @Override
    public void actionPerformed(ActionEvent evt) {
        // Do some work...
    }
    
}

//...

for (int i = 0; i <= 7; i++) {
    for (int j = 0; j <= 7; j++) {

        btn = new JButton(new CardAction(i, j));
        f.add(btn);
    }

}

我试图实现的一个目标是将动作功能与按钮本身分离，因此动作不依赖于按钮，而是依赖于提供的执行其操作所需的信息。

这是“模型-视图-控制器”的核心概念，将使您的代码更易于维护