我想把按钮添加到所有这些面板,所以我可以检查它们是否被点击。我对Java还是一个新手,这就是我们如何去做的。这一行给出了一个空指针,我不知道为什么
现在我正在制作一个大面板,并在其上添加48个新面板,然后在每个面板上添加按钮,以便我可以制作一个动作事件。如果我有办法检查我是否点击了面板,那么我可以做到这一点,但我不知道如何。
我在“panel [x] .add(单击[x])”;行上收到NullPointerException;“
package CatchTheMouse;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CatchTheMouse extends JFrame implements ActionListener, MouseListener{
final int ROWS = 8;
final int COLS = 6;
final int GAP = 2;
final int MAX_PANELS = ROWS * COLS;
int clicks;
int hits;
int percentage = 0;
int width;
int height;
int panelX;
int panelY;
int whichPanel = (int)(Math.random() * 47 + 1);
JButton[] click = new JButton[MAX_PANELS];
JLabel grats = new JLabel("");
JLabel spot = new JLabel("X");
JPanel[] panel = new JPanel[MAX_PANELS];
JPanel pane = new JPanel(new GridLayout(ROWS, COLS, GAP, GAP));
Font xFont = new Font("Ariel", Font.BOLD, 20);
Font font = new Font("Ariel", Font.PLAIN, 12);
public CatchTheMouse() {
super("Catch the Mouse");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(300,300);
add(spot);
spot.setFont(xFont);
add(grats);
grats.setFont(font);
add(pane);
for(int x = 0; x < MAX_PANELS; ++x) {
panel[x] = new JPanel();
pane.add(panel[x]);
panel[x].setBackground(Color.RED);
panel[x].add(click[x]);
click[x].addActionListener(this);
click[x].setVisible(false);
}
pane.setBackground(Color.BLACK);
panel[whichPanel].add(spot);
}
public void mouseClicked(MouseEvent e) {
clicks = e.getClickCount();
}
public void mouseEntered(MouseEvent e) {
}
public void mouseExited(MouseEvent e) {
}
public void mousePressed(MouseEvent e) {
}
public void mouseReleased(MouseEvent e) {
}
public void actionPerformed(ActionEvent e) {
Object src = e.getSource();
if(src == click[whichPanel]) {
hits++;
grats.setText("You have made " + Integer.toString(hits) + " hits");
}
}
public static void main(String[] args) {
CatchTheMouse frame = new CatchTheMouse();
frame.setVisible(true);
}
}
我做到了。我意识到我没有包括它,所以我编辑英寸这样说 – buckley183 2014-12-06 05:37:21