在每一列上使用GridBagLayout和JPanel创建JPanel

Question

我试图在每个列上创建JPanel与GridBagLayout和面板。但是当我运行程序时，我总是在网格上得到一个面板，尽管我有一个循环来创建10X10的面板。

ColumnPanel

public class BoardColumnPanel extends JPanel {
public BoardColumnPanel() {
    this.setBackground(Color.GRAY);
    this.setSize(48, 48);
}
}

网格视图

public class BoardPanel extends JPanel {
private GridBagLayout layout;
public BoardPanel() {
    initBoardPanel();
}
private void initBoardPanel() {
    layout = new GridBagLayout();
    this.setLayout(layout);
    GridBagConstraints gridBagConstraints = new GridBagConstraints();
    gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
    // fill grid
    BoardColumnPanel column;
    for (int row=0;row<10;row++) {
        for (int col=0; col < 10; col++) {
            column = new BoardColumnPanel();
            gridBagConstraints.gridx = col;
            gridBagConstraints.gridy = row;
            gridBagConstraints.ipadx = 5;
            gridBagConstraints.ipady = 5;
            layout.setConstraints(column,gridBagConstraints);
            this.add(column);
        }
    }
}
}

Answer 1

我建议使用GridLayout，注意通过使用这个LayoutManager每个JComponents将在屏幕上有相同的大小，

Answer 2

您的代码没问题。让我们改变BoardColumnPanel的背景颜色:

public class BoardColumnPanel extends JPanel {
  public BoardColumnPanel(int i) {
        this.setBackground(new Color(10 * i, 10 * i, 10 * i));
        this.setSize(48, 48);
    }
}

并初始化为不同的灰色:

public class BoardPanel extends JPanel {
  private GridBagLayout layout;
  public BoardPanel() {
    initBoardPanel();
  }
  private void initBoardPanel() {
    layout = new GridBagLayout();
    this.setLayout(layout);
    GridBagConstraints gridBagConstraints = new GridBagConstraints();
    gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
    // fill grid
    BoardColumnPanel column;
    for (int row = 0; row < 10; row++) {
      for (int col = 0; col < 10; col++) {
        column = new BoardColumnPanel(row + col);
        gridBagConstraints.gridx = col;
        gridBagConstraints.gridy = row;
        gridBagConstraints.ipadx = 5;
        gridBagConstraints.ipady = 5;
        layout.setConstraints(column, gridBagConstraints);
        this.add(column);
      }
    }
  }
  public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
      @Override
      public void run() {
        JFrame f = new JFrame();
        f.getContentPane().add(new BoardPanel());
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
      }
    });
  }
}

Answer 3

我不完全确定，但我想说GridBagConstraints = new GridBagConstraints();需要在 for循环内的。否则，您将重复为相同的约束设置gridx/gridy。