java - 我们如何在GridLayout中显示网格线？

我们如何在GridLayout中显示网格线？在Java中？

JPanel panel = new JPanel(new GridLayout(10,10));
panel.setBorder(BorderFactory.createEmptyBorder(2,2,2,2));

for (int i =0; i<(10*10); i++){
   panel.add(new JLabel("Label"));
}

最佳答案

我会尝试通过向组件添加边框来做到这一点。简单的方法就是使用BorderFactory.createLineBorder()，如下所示:

JPanel panel = new JPanel(new GridLayout(10,10));
panel.setBorder(BorderFactory.createEmptyBorder(2,2,2,2));

for (int i =0; i<(10*10); i++){
    final JLabel label = new JLabel("Label");
    label.setBorder(BorderFactory.createLineBorder(Color.BLACK));
    panel.add(label);
}

但是，这将使您在单元格之间的边框比在面板的边缘处更粗，因为外部边缘将仅具有一个像素的粗边框，而内部边缘将具有两个一像素的粗边框。要解决此问题，您可以使用BorderFactory.createMatteBorder()在所有位置仅绘制一个像素宽的边框:

final int borderWidth = 1;
final int rows = 10;
final int cols = 10;
JPanel panel = new JPanel(new GridLayout(rows, cols));
panel.setBorder(BorderFactory.createEmptyBorder(2,2,2,2));

for (int row = 0; row < rows; row++) {
    for (int col = 0; col < cols; col++) {
        final JLabel label = new JLabel("Label");
        if (row == 0) {
            if (col == 0) {
                // Top left corner, draw all sides
                label.setBorder(BorderFactory.createLineBorder(Color.BLACK));
            }
            else {
                // Top edge, draw all sides except left edge
                label.setBorder(BorderFactory.createMatteBorder(borderWidth,
                                                                0,
                                                                borderWidth,
                                                                borderWidth,
                                                                Color.BLACK));
            }
        }
        else {
            if (col == 0) {
                // Left-hand edge, draw all sides except top
                label.setBorder(BorderFactory.createMatteBorder(0,
                                                                borderWidth,
                                                                borderWidth,
                                                                borderWidth,
                                                                Color.BLACK));
            }
            else {
                // Neither top edge nor left edge, skip both top and left lines
                label.setBorder(BorderFactory.createMatteBorder(0,
                                                                0,
                                                                borderWidth,
                                                                borderWidth,
                                                                Color.BLACK));
            }
        }
        panel.add(label);
    }
}

这应该为您提供到单元格之间以及沿外部边缘的各处borderWidth宽度的边界。