检查单击了哪个 Jbutton(多个 Jbutton)

Question

我正在制作一个棋盘游戏，8X8矩阵，一帧有64JButton秒。 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);

我试图使用以下代码判断单击了哪个 JButoon：

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，我不明白如何判断点击了哪个 Jbutton。

Answer 1

让我们从static不是你的朋友开始，你应该避免使用它，尤其是当你尝试跨对象边界引用实例时。

你可以...

使用匿名类，例如...

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btnstatic，这不会对您有所帮助

你可以...

利用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);
}
}

你可以...

创建一个自定义ActionListener，该获取所需信息，以便它可以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);
}
}

你可以...

我个人的偏好是使用ActionAPI。

这与上一个建议类似，但创建了一个更加独立的工作单元，该工作单元与调用程序分离。

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);
}
}

什么是重要的...

我正在尝试的一件事是将操作功能与按钮本身分离，因此操作不依赖于按钮，而是依赖于提供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

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() );
}

但是最好将所有按钮放在 ArrayList 中，然后只使用int index = list.indexOf(src);

Answer 3

实现 MadProgrammer 建议的 MVC 模式可以按如下方式完成：
有一个包含视图 (gui( 所需的所有信息的Model类。
有一个使用该模型显示 gui 的View类。
具有控制模型和视图的Controller类。

以下 mre 演示如何使用 MVC 模式来实现所需的功能。
为了方便和简单起见，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));
}
}