我们如何在GridLayout中显示网格线？

java swing grid-layout

2022-09-02 12:15:31

我们如何在GridLayout中显示网格线？在爪哇？

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"));
}

答案 1

我会尝试通过在添加组件时向它们添加边框来做到这一点。执行此操作的简单方法是使用，如下所示：BorderFactory.createLineBorder()

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，这将使单元格之间的边框比面板边缘的边框更粗，因为外边缘将只有一个像素粗边框，而内边缘将具有两个一像素厚的边框。要解决此问题，您可以使用仅在所有位置绘制一个像素范围的边框：BorderFactory.createMatteBorder()

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);
    }
}

这应该为您提供所有位置的宽度边框，包括单元格之间和沿外边缘。borderWidth

答案 2

对于Joe Carnahan提到的厚边界问题，有一个更简单的方法：将组件之间的垂直间隙和水平间隙设置为-1。所以完整的代码是：GridLayout(10,10, -1, -1)

JPanel panel = new JPanel(new GridLayout(10,10, -1, -1));
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);
}