为什么此GridBagLayout不能按计划显示? [英] Why does this GridBagLayout not appear as planned?
问题描述
我试图达到在GridBagLayout中设置任意宽度的最终结果.
I was trying to achieve the end result required in Setting an arbitrary width in GridBagLayout.
为便于参考，这里是:
这是当前结果:
按钮编号和行以1,1的形式显示，后跟为此单元格声明的列(2)的数量.
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)开头，其下方的1,2 (4)宽度相同，同时声明了不同的列数.
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.
任何人都可以确定如何更正代码吗?
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
在图片中，每行包含5到8个按钮，这意味着GridBagLayout仅知道8个单独列的宽度.
From the picture each row contains 5 to 8 buttons, which means the GridBagLayout only knows about the width of 8 individual columns.
将(..)中的数字相加，表示每一行的总数gridwidth.总数是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8列变成22列.它不知道要在列中没有组件的列使用什么宽度.因此，布局不知道如何处理gridwidth约束.
The GridBagLayout doesn't know how to turn 8 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网格中预期的列数以及网格中每一列的最小宽度.
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该列的最小宽度"(每个列可以不同).
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.
更新的代码如下:
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提供了创建网格的功能，并且仅用组件填充了网格的几个单元格.
This means the GridBagLayout provides the ability to create a grid and only fill a few cells of the grid with components.
这篇关于为什么此GridBagLayout不能按计划显示?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！
