Question

我正在尝试使用附加到每个按钮的图标来构建匹配游戏。虽然这还没有完成，但是我在用按钮填充面板时遇到了问题。

使用此代码，我得到一个灰色的框架。如果我注释掉我在＆＃34; //执行＆＃34;下使用的3种方法。面板将全部为黑色（这就是我测试的方式，看看按钮是否填满了空间。）

对于某些原因，我的按钮没有被填充到面板上我需要一些帮助！！！我哪里错了？

import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class MemoryMainFrame extends JFrame implements ActionListener {

    JButton button[] = new JButton[16];
    private static final int SIXTEEN_BUTTONS = 16;
    JPanel mainPanel = new JPanel();
    double dim = Math.sqrt(SIXTEEN_BUTTONS);
    int numOfColumns = (int) (dim);
    int numOfRows = (int) (dim);

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

    public MemoryMainFrame() {

        this.setTitle("MemoryGame!!!");
        this.setSize(400, 400);
        this.setLocationRelativeTo(null);
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        this.setVisible(true);

        mainPanel.setBackground(Color.BLACK);
        mainPanel.setLayout(new GridBagLayout());

        // execution
        FillButtonArray(SIXTEEN_BUTTONS);
        AddButtonListener(SIXTEEN_BUTTONS);
        ButtonToPanel(SIXTEEN_BUTTONS);

        this.add(mainPanel);
    }

    public void FillButtonArray(int numOfButtons) {
        int i = 0;

        while (i < numOfButtons) {
            button[i] = new JButton("asdf");
        }
    }

    public void AddButtonListener(int numOfButtons) {
        int i = 0;

        while (i < numOfButtons) {
            button[i].addActionListener(this);
        }
    }

    public void ButtonToPanel(int numOfButtons) {
        int n = 0;
        GridBagConstraints gbc = new GridBagConstraints();

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

                gbc.gridx = i;
                gbc.gridy = j;
                n++;

                button[n].setBorder(BorderFactory.createLineBorder(
                        Color.DARK_GRAY, 2));
                mainPanel.add(button[n]);
            }
        }
    }

    public void actionPerformed(ActionEvent arg0) {

        JFrame j = new JFrame();
        j.setSize(300, 300);
        j.setVisible(true);
    }
}

我使用＆＃34; asdf＆＃34;作为测试，看看按钮是否也能正常工作。

此外，执行的行动也是一项测试。那段代码是无关紧要的。

Answer 1

您正在创建GridBagConstraints，但您并未使用它们。

改变这个：

mainPanel.add(button[n]);

到此：

// passes both the component and the GBC into the container
mainPanel.add(button[n], gbc);

修改
你在这里也有一个永无止境的循环：

while (i < numOfButtons) { button[i] = new JButton("asdf"); }

同样适用于AddButtonListener(...)方法。

您希望通过使用for循环或在循环中更改i来解决此问题。

根据Andrew Thompson的评论，在添加所有组件之前，您过早地设置了JFrame。

此外，您使用Math.sqrt然后将结果转换为int是非常危险的，并且可能会产生意外结果。如果需要，只需将边长声明为8并将int平方。

有关GridBagLayout的示例，请查看：

import java.awt.Color; import java.awt.Component; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.Insets; import java.awt.event.ActionEvent; import javax.swing.*; @SuppressWarnings("serial") // avoid extending JFrame if possible public class MemoryMainPanel extends JPanel { private static final int ROWS = 8; private static final Color BACKGROUND = Color.black; private static final int I_GAP = 5; private static final Insets BTN_INSETS = new Insets(I_GAP, I_GAP, I_GAP, I_GAP); private JButton[][] buttons = new JButton[ROWS][ROWS]; public MemoryMainPanel() { setBackground(BACKGROUND); setLayout(new GridBagLayout()); for (int row = 0; row < buttons.length; row++) { for (int col = 0; col < buttons[row].length; col++) { JButton btn = new JButton(new ButtonAction(row, col)); add(btn, createGbc(row, col)); buttons[row][col] = btn; } } } private GridBagConstraints createGbc(int y, int x) { GridBagConstraints gbc = new GridBagConstraints(); gbc.gridx = x; gbc.gridy = y; gbc.weightx = 1.0; gbc.weighty = 1.0; gbc.insets = BTN_INSETS; return gbc; } private class ButtonAction extends AbstractAction { private int row; private int col; public ButtonAction(int row, int col) { super("asdf"); this.row = row; this.col = col; } @Override public void actionPerformed(ActionEvent e) { String text = String.format("Column, Row: [%d, %d]", col + 1, row + 1); Component parentComponent = MemoryMainPanel.this; String message = text; String title = "Button Pressed"; int messageType = JOptionPane.PLAIN_MESSAGE; Icon icon = null; JOptionPane.showMessageDialog(parentComponent, message, title, messageType, icon); } } private static void createAndShowGui() { MemoryMainPanel mainPanel = new MemoryMainPanel(); JFrame frame = new JFrame("MemoryMainPanel"); frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); frame.getContentPane().add(mainPanel); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGui(); } }); } }

使用GridBagLayout使用按钮填充框架

1 个答案: