Java GridLayout 将我所有的 JPanel 布局在左上角
已解决：
在尝试制作 SSCCE 后才发现问题所在。
这与我的单元类有关，我没有意识到我正在重写 JComponent 类中的 getX() 和 getY() 。
重命名这些访问器后，一切都按预期工作
============================================
我有一个 JPanel，其 GridLayout 设置为 3 行 x 3 列。
我正在尝试将 JPanel 添加到网格布局中的每个单元格以填充所有 9 个单元格。 这些 JPanel 中的每一个都有一个重写的 PaintChildren 方法，该方法将从 JPanel 的左上角开始绘制某种矩形 - 最终结果将是每个单元格中都有一个从单元格的左上角开始的矩形。
将所有 JPanel 添加到网格布局后，它们都出现在左上角，彼此重叠（我已确认它们是重叠的），而不是放置在 3x3 网格中。
如何将它们排列在 3x3 网格中？
（简化）代码：
public class Panel extends JPanel {
public Panel(int x, int y) {
layout = new GridLayout(x, y, 2, 2);
setLayout(layout);
populateGrid();
}
public void populateGrid() {
removeAll();
for (int i = 0; i < 9; i++)
add(new Cell(50,50));
}
}
public class Cell extends JPanel {
public Cell(int x, int y) {
// x/y values used to define rectangle
setBorder(BorderFactory.createLineBorder(new Color(0,0,0)));
setBackground(Color.WHITE);
}
public void paintChildren(Graphics g) {
g.setColor(Color.BLUE);
g.fillRect(0, 0, x, y);
}
}
SOLVED:
Just found out what the problem was, after trying to make an SSCCE.
It had to do with my cell class, I didn't realise I was overriding getX() and getY() from the JComponent class.
After renaming these accessors it all works as expected
========================================
I have a JPanel with a GridLayout set at 3 rows x 3 cols.
I'm trying to add JPanels to each cell in the gridlayout to fill up all 9 cells.
Each one of these JPanels has an overriden paintChildren method which will paint some kind of rectangle starting at the top left of the JPanel - the end result will be each cell has a rectangle in it starting at the top left of the cell.
After adding all the JPanels to the gridlayout, they all appear in the top left corner overlapping each other (I have confirmed they are overlapping), instead of being laid out in a 3x3 grid.
How can I get them arranged in the 3x3 grid?
(Simplified) Code:
public class Panel extends JPanel {
public Panel(int x, int y) {
layout = new GridLayout(x, y, 2, 2);
setLayout(layout);
populateGrid();
}
public void populateGrid() {
removeAll();
for (int i = 0; i < 9; i++)
add(new Cell(50,50));
}
}
public class Cell extends JPanel {
public Cell(int x, int y) {
// x/y values used to define rectangle
setBorder(BorderFactory.createLineBorder(new Color(0,0,0)));
setBackground(Color.WHITE);
}
public void paintChildren(Graphics g) {
g.setColor(Color.BLUE);
g.fillRect(0, 0, x, y);
}
}
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评论（1）
确保导入正确的
面板。 （而不是java.awt.Panel类。）或者，更好的方法是将您的类重命名为GridPanel或类似的名称，以避免混淆/冲突。您可能不想覆盖
paintChildren。在这种情况下，覆盖paintComponent听起来是更好的选择。您可能希望为
Cell类设置最小/首选/最大大小。如果没有实例化和使用
Panel类的实际代码，很难进行更多观察。Make sure you import the right
Panel. (And not thejava.awt.Panelclass.) Or, better, rename your class toGridPanelor something similar to avoid confusion / clashes.You probably don't want to override
paintChildren. OverridingpaintComponentsounds like a better option in this case.You may want to set minimum / preferred / maximum size for the
Cellclass.Hard to make more observations without the actual code that instantiates and uses your
Panelclass.