为什么这个 GridBagLayout 没有按计划出现? [英] Why does this GridBagLayout not appear as planned?
问题描述
我试图达到 在 GridBagLayout 中设置任意宽度 中所需的最终结果.
I was trying to achieve the end result required in Setting an arbitrary width in GridBagLayout.
为了方便参考，这里是:
For easy reference, here it is:
这是当前的结果:
按钮编号和行以1,1的形式显示，后跟为该单元格声明的列数(2).
Button number and row is shown in the form 1,1, followed by the number of columns (2) declared for this cell.
如您所见，它以按钮 1,1 (3) 开始，其下方的 1,2 (4) 具有相同的宽度，同时声明不同的数字列.
As you can see, it starts with buttons 1,1 (3) and below it 1,2 (4) being the same width, while declaring different numbers of columns.
谁能确定如何更正代码?
Can anyone determine how to correct the code?
当前代码:
import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class KeyBoardLayout {
private JComponent ui = null;
KeyBoardLayout() {
initUI();
}
public void initUI() {
if (ui!=null) return;
ui = new JPanel(new GridBagLayout());
ui.setBorder(new EmptyBorder(4,4,4,4));
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.gridwidth = 3;
gbc.fill = GridBagConstraints.HORIZONTAL;
ui.add(new JButton("1,1 (3)"), gbc);
gbc.gridx = 3;
gbc.gridwidth = 2;
ui.add(new JButton("2,1 (2)"), gbc);
gbc.gridx = 5;
ui.add(new JButton("3,1 (2)"), gbc);
gbc.gridx = 7;
ui.add(new JButton("4,1 (2)"), gbc);
gbc.gridx = 9;
ui.add(new JButton("5,1 (2)"), gbc);
gbc.gridx = 11;
ui.add(new JButton("6,1 (2)"), gbc);
gbc.gridx = 13;
ui.add(new JButton("7,1 (2)"), gbc);
gbc.gridx = 15;
gbc.gridwidth = 3;
ui.add(new JButton("8,1 (3)"), gbc);
gbc.gridx = 18;
gbc.gridwidth = 4;
ui.add(new JButton("9,1 (4)"), gbc);
gbc.gridx = 0;
gbc.gridy = 1;
ui.add(new JButton("1,2 (4)"), gbc);
gbc.gridx = 4;
gbc.gridwidth = 2;
ui.add(new JButton("2,2 (2)"), gbc);
gbc.gridx = 6;
ui.add(new JButton("3,2 (2)"), gbc);
gbc.gridx = 8;
ui.add(new JButton("4,2 (2)"), gbc);
gbc.gridx = 10;
ui.add(new JButton("5,2 (2)"), gbc);
gbc.gridx = 12;
ui.add(new JButton("6,2 (2)"), gbc);
gbc.gridx = 14;
ui.add(new JButton("7,2 (2)"), gbc);
gbc.gridx = 16;
ui.add(new JButton("8,2 (2)"), gbc);
gbc.gridx = 18;
gbc.gridwidth = 4;
ui.add(new JButton("9,2 (4)"), gbc);
gbc.gridx = 0;
gbc.gridy = 2;
gbc.gridwidth = 5;
ui.add(new JButton("1,3 (5)"), gbc);
gbc.gridx = 5;
gbc.gridwidth = 2;
ui.add(new JButton("2,3 (2)"), gbc);
gbc.gridx = 7;
ui.add(new JButton("3,3 (2)"), gbc);
gbc.gridx = 9;
ui.add(new JButton("4,3 (2)"), gbc);
gbc.gridx = 11;
ui.add(new JButton("5,3 (2)"), gbc);
gbc.gridx = 13;
ui.add(new JButton("6,3 (2)"), gbc);
gbc.gridx = 15;
ui.add(new JButton("7,3 (2)"), gbc);
gbc.gridx = 17;
ui.add(new JButton("8,3 (2)"), gbc);
gbc.gridx = 19;
gbc.gridwidth = 3;
ui.add(new JButton("9,3 (3)"), gbc);
gbc.gridx = 0;
gbc.gridy = 3;
gbc.gridwidth = 3;
ui.add(new JButton("1,4 (3)"), gbc);
gbc.gridx = 3;
ui.add(new JButton("2,4 (3)"), gbc);
gbc.gridx = 6;
gbc.gridwidth = 10;
ui.add(new JButton("3,4 (10)"), gbc);
gbc.gridx = 16;
gbc.gridwidth = 3;
ui.add(new JButton("4,4 (3)"), gbc);
gbc.gridx = 19;
ui.add(new JButton("5,4 (3)"), gbc);
}
public JComponent getUI() {
return ui;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception useDefault) {
}
KeyBoardLayout o = new KeyBoardLayout();
JFrame f = new JFrame("Keyboard Layout");
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.setLocationByPlatform(true);
f.setContentPane(o.getUI());
f.pack();
f.setMinimumSize(f.getSize());
f.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
}
推荐答案
从图片中每行包含 5 到 9 个按钮，这意味着 GridBagLayout 只知道 9 个单独列的宽度.
From the picture each row contains 5 to 9 buttons, which means the GridBagLayout only knows about the width of 9 individual columns.
将 (..) 中的数字相加，表示每行的总 gridwidth.总数为 22.
Add up the numbers in the (..) which indicate the total gridwidth for each row. The total is 22.
GridBagLayout 不知道如何将 9 列变成 22 列.它不知道列中没有组件的列使用什么宽度.所以布局不知道如何处理 gridwidth 约束.
The GridBagLayout doesn't know how to turn 9 columns into 22 columns. It doesn't know what widths to use for columns without a component in the column. So the layout doesn't know how to handle the gridwidth constraint.
解决方案是告诉 GridBagLayout 网格中的预期列数和网格中每列的最小宽度.
The solution is to tell the GridBagLayout the intended number of columns in the grid and the minimum width of each column in the grid.
这可以通过设置 GridBagLayout 本身的值来完成:
This can be done by setting values of the GridBagLayout itself:
//ui = new JPanel(new GridBagLayout());
int[] columns = new int[22];
Arrays.fill(columns, 30);
GridBagLayout gbl = new GridBagLayout();
gbl.columnWidths = columns;
ui = new JPanel(gbl);
数组的大小定义了列数.
The size of the array defines the number of columns.
分配给数组中每个条目的值是最小宽度"；列(每列可以不同).
The value assigned to each entry in the array is the "minimum width" of the column (it can be different for each column).
现在 GridBagLayout 知道如何计算每列的宽度，并且使用 gridwidth 作为每个组件的约束将按预期工作.
Now the GridBagLayout knows how to calculate a width for each column and using gridwidth as a constraint for each component will work as expected.
更新代码如下:
import java.awt.*;
import java.util.Arrays;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class KeyBoardLayout {
private JComponent ui = null;
KeyBoardLayout() {
initUI();
}
public void initUI() {
if (ui!=null) return;
//ui = new JPanel(new GridBagLayout());
int[] columns = new int[22];
Arrays.fill(columns, 30);
GridBagLayout gbl = new GridBagLayout();
gbl.columnWidths = columns;
ui = new JPanel(gbl);
ui.setBorder(new EmptyBorder(4,4,4,4));
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.gridwidth = 3;
gbc.fill = GridBagConstraints.HORIZONTAL;
ui.add(new JButton("1,1 (3)"), gbc);
gbc.gridx = 3;
gbc.gridwidth = 2;
ui.add(new JButton("2,1 (2)"), gbc);
gbc.gridx = 5;
ui.add(new JButton("3,1 (2)"), gbc);
gbc.gridx = 7;
ui.add(new JButton("4,1 (2)"), gbc);
gbc.gridx = 9;
ui.add(new JButton("5,1 (2)"), gbc);
gbc.gridx = 11;
ui.add(new JButton("6,1 (2)"), gbc);
gbc.gridx = 13;
ui.add(new JButton("7,1 (2)"), gbc);
gbc.gridx = 15;
gbc.gridwidth = 3;
ui.add(new JButton("8,1 (3)"), gbc);
gbc.gridx = 18;
gbc.gridwidth = 4;
ui.add(new JButton("9,1 (4)"), gbc);
gbc.gridx = 0;
gbc.gridy = 1;
ui.add(new JButton("1,2 (4)"), gbc);
gbc.gridx = 4;
gbc.gridwidth = 2;
ui.add(new JButton("2,2 (2)"), gbc);
gbc.gridx = 6;
ui.add(new JButton("3,2 (2)"), gbc);
gbc.gridx = 8;
ui.add(new JButton("4,2 (2)"), gbc);
gbc.gridx = 10;
ui.add(new JButton("5,2 (2)"), gbc);
gbc.gridx = 12;
ui.add(new JButton("6,2 (2)"), gbc);
gbc.gridx = 14;
ui.add(new JButton("7,2 (2)"), gbc);
gbc.gridx = 16;
ui.add(new JButton("8,2 (2)"), gbc);
gbc.gridx = 18;
gbc.gridwidth = 4;
ui.add(new JButton("9,2 (4)"), gbc);
gbc.gridx = 0;
gbc.gridy = 2;
gbc.gridwidth = 5;
ui.add(new JButton("1,3 (5)"), gbc);
gbc.gridx = 5;
gbc.gridwidth = 2;
ui.add(new JButton("2,3 (2)"), gbc);
gbc.gridx = 7;
ui.add(new JButton("3,3 (2)"), gbc);
gbc.gridx = 9;
ui.add(new JButton("4,3 (2)"), gbc);
gbc.gridx = 11;
ui.add(new JButton("5,3 (2)"), gbc);
gbc.gridx = 13;
ui.add(new JButton("6,3 (2)"), gbc);
gbc.gridx = 15;
ui.add(new JButton("7,3 (2)"), gbc);
gbc.gridx = 17;
ui.add(new JButton("8,3 (2)"), gbc);
gbc.gridx = 19;
gbc.gridwidth = 3;
ui.add(new JButton("9,3 (3)"), gbc);
gbc.gridx = 0;
gbc.gridy = 3;
gbc.gridwidth = 3;
ui.add(new JButton("1,4 (3)"), gbc);
gbc.gridx = 3;
ui.add(new JButton("2,4 (3)"), gbc);
gbc.gridx = 6;
gbc.gridwidth = 10;
ui.add(new JButton("3,4 (10)"), gbc);
gbc.gridx = 16;
gbc.gridwidth = 3;
ui.add(new JButton("4,4 (3)"), gbc);
gbc.gridx = 19;
ui.add(new JButton("5,4 (3)"), gbc);
}
public JComponent getUI() {
return ui;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception useDefault) {
}
KeyBoardLayout o = new KeyBoardLayout();
JFrame f = new JFrame("Keyboard Layout");
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.setLocationByPlatform(true);
f.setContentPane(o.getUI());
f.pack();
f.setMinimumSize(f.getSize());
f.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
}
这种方法也可以用于行.
This approach can be used for rows as well.
这意味着 GridBagLayout 提供了创建网格并仅用组件填充网格的几个单元格的能力.
This means the GridBagLayout provides the ability to create a grid and only fill a few cells of the grid with components.
这篇关于为什么这个 GridBagLayout 没有按计划出现?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
