java - 如何在java布局中左对齐标签？

Question

我正在尝试将标签向左对齐。布局管理器根本无法直观地或按预期工作。

我浏览了互联网，但没有任何内容解释我需要什么。或者我发现的例子根本不起作用。例如，我已经设置了所有对齐参数，但没有任何变化。

请帮忙。

Labels do not left align.

“我已经尝试了所有类型的布局和所有对齐设置。”

  JPanel p0=new JPanel();
  p0.setLayout(new BoxLayout(p0,BoxLayout.Y_AXIS));
  p0.setBorder(new EmptyBorder(10,10,10,10));
  p0.setAlignmentX(0);

  JPanel p0a=new JPanel();
  p0a.setLayout(new BoxLayout(p0a,BoxLayout.X_AXIS));
  JLabel l=new JLabel("Label 1");
  p0a.add(l);
  p0a.setAlignmentX(0);
  l.setAlignmentX(0);
  l.setHorizontalAlignment(0);

  p0.add(p0a);

  JPanel p0b=new JPanel();
  p0b.setLayout(new BoxLayout(p0b,BoxLayout.Y_AXIS));
  p0b.add(new JLabel("Label 1"));
  p0.add(p0b);

  JPanel p0c=new JPanel();
  p0c.setLayout(new BoxLayout(p0c,BoxLayout.Y_AXIS));
  p0c.add(new JLabel("Label 1"));
  p0.add(p0c);

"create labels"


  JPanel p1=new JPanel();
  p1.setLayout(new BoxLayout(p1,BoxLayout.X_AXIS));
  p1.add(new JLabel("Label 4a"));
  p1.add(new JLabel("Label 4b"));
  p1.add(new JLabel("Label 4c"));
  p1.add(new JLabel("Label 4d"));
  p0.add(p1);

  p0.add(new JLabel("Label 5"));
  p0.add(new JLabel("Label 6"));
  p0.add(new JLabel("Label 7"));

  JDialog jd=new JDialog();
  jd.addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent _e){jd.setVisible(false);}});
  jd.setLayout(new BoxLayout(jd.getContentPane(),BoxLayout.Y_AXIS));
  Container c=jd.getContentPane();
  jd.setLayout(new BoxLayout(c,BoxLayout.Y_AXIS));
  c.add(p0);
  jd.pack();
  jd.setVisible(true);

“标签未向左对齐。”

Answer 1

当X对齐设置为LEFT_ALIGNMENT时，添加到父级的所有组件都将左对齐。 RIGHT_ALIGNMENT 也是如此。当混合行为不同时。

要至少解决您的问题，只需将设置 X 对齐添加到水平添加多个标签的面板即可。

JPanel p1=new JPanel();
p1.setLayout(new BoxLayout(p1,BoxLayout.X_AXIS));
p1.add(new JLabel("Label 4a"));
p1.add(new JLabel("Label 4b"));
p1.add(new JLabel("Label 4c"));
p1.add(new JLabel("Label 4d"));
p1.setAlignmentX(Component.LEFT_ALIGNMENT);

其他选项

有很多选择 - 一致地使用简单的 X 对齐，另一个复杂的选项是使用 Box。

设置所有子组件的 X 对齐方式

第一个选项是在添加到父组件的子组件上使用 setAlignmentX(Component.LEFT_ALIGNMENT)。

private static void addAndLeftAlign(JComponent parent, JComponent child) {
    child.setAlignmentX(Component.LEFT_ALIGNMENT);
    parent.add(child);
}

这是您修改后的代码:

import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Random;

public class LeftAlignLabels57538179 {
    public static void main(String[] args) {
        JPanel p0 = new JPanel();
        //p0.setBackground(Color.ORANGE);
        p0.setLayout(new BoxLayout(p0, BoxLayout.Y_AXIS));
        p0.setBorder(new EmptyBorder(10, 10, 10, 10));
        p0.setAlignmentX(0);

        JPanel p0a = new JPanel();
        p0a.setLayout(new BoxLayout(p0a, BoxLayout.X_AXIS));
        JLabel l = new JLabel("Label 1");
        p0a.add(l);
        //p0a.setAlignmentX(0);
        //l.setAlignmentX(0);
        //l.setHorizontalAlignment(0);

        //p0.add(p0a);
        addAndLeftAlign(p0, p0a);

        JPanel p0b = new JPanel();
        p0b.setLayout(new BoxLayout(p0b, BoxLayout.Y_AXIS));
        p0b.add(new JLabel("Label 1"));
        //p0.add(p0b);
        addAndLeftAlign(p0, p0b);

        JPanel p0c = new JPanel();
        p0c.setLayout(new BoxLayout(p0c, BoxLayout.Y_AXIS));
        p0c.add(new JLabel("Label 1"));
        //p0.add(p0c);
        addAndLeftAlign(p0, p0c);
        //"create labels"


        JPanel p1 = new JPanel();
        p1.setLayout(new BoxLayout(p1, BoxLayout.X_AXIS));
        p1.add(new JLabel("Label 4a"));
        p1.add(new JLabel("Label 4b"));
        p1.add(new JLabel("Label 4c"));
        p1.add(new JLabel("Label 4d"));
        //p0.add(p1);
        addAndLeftAlign(p0, p1);

        addAndLeftAlign(p0, new JLabel("Label 5"));
        addAndLeftAlign(p0, new JLabel("Label 6"));
        addAndLeftAlign(p0, new JLabel("Label 7"));

        JDialog jd = new JDialog();
        jd.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent _e) {
                jd.setVisible(false);
            }
        });
        jd.setLayout(new BoxLayout(jd.getContentPane(), BoxLayout.Y_AXIS));
        Container c = jd.getContentPane();
        jd.setLayout(new BoxLayout(c, BoxLayout.Y_AXIS));
        c.add(p0);
        jd.pack();
        jd.setVisible(true);
    }

    private static void addAndLeftAlign(JComponent parent, JComponent child) {
        child.setAlignmentX(Component.LEFT_ALIGNMENT);
        parent.add(child);
    }
}

框选项

左对齐另一个选项以通过以下方式使用 Box 一个非常轻量级的组件:

private static void addAndLeftAlign(JComponent parent, JComponent child){
    Box  b = Box.createHorizontalBox();
    b.add(child);
    b.add( Box.createHorizontalGlue() );
    parent.add(b);
}

这是您修改后的代码:

import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class LeftAlignLabels57538179 {
    public static void main(String[] args) {
        JPanel p0=new JPanel();
        p0.setLayout(new BoxLayout(p0,BoxLayout.Y_AXIS));
        p0.setBorder(new EmptyBorder(10,10,10,10));
        p0.setAlignmentX(0);

        JPanel p0a=new JPanel();
        p0a.setLayout(new BoxLayout(p0a,BoxLayout.X_AXIS));
        JLabel l=new JLabel("Label 1");
        p0a.add(l);
        p0a.setAlignmentX(0);
        l.setAlignmentX(0);
        l.setHorizontalAlignment(0);

        //p0.add(p0a);
        addAndLeftAlign(p0, p0a);

        JPanel p0b=new JPanel();
        p0b.setLayout(new BoxLayout(p0b,BoxLayout.Y_AXIS));
        p0b.add(new JLabel("Label 1"));
        //p0.add(p0b);
        addAndLeftAlign(p0, p0b);

        JPanel p0c=new JPanel();
        p0c.setLayout(new BoxLayout(p0c,BoxLayout.Y_AXIS));
        p0c.add(new JLabel("Label 1"));
        //p0.add(p0c);
        addAndLeftAlign(p0, p0c);
        //"create labels"


        JPanel p1=new JPanel();
        p1.setLayout(new BoxLayout(p1,BoxLayout.X_AXIS));
        p1.add(new JLabel("Label 4a"));
        p1.add(new JLabel("Label 4b"));
        p1.add(new JLabel("Label 4c"));
        p1.add(new JLabel("Label 4d"));
        //p0.add(p1);
        addAndLeftAlign(p0, p1);

        addAndLeftAlign(p0, new JLabel("Label 5"));
        addAndLeftAlign(p0, new JLabel("Label 6"));
        addAndLeftAlign(p0, new JLabel("Label 7"));

        JDialog jd=new JDialog();
        jd.addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent _e){jd.setVisible(false);}});
        jd.setLayout(new BoxLayout(jd.getContentPane(),BoxLayout.Y_AXIS));
        Container c=jd.getContentPane();
        jd.setLayout(new BoxLayout(c,BoxLayout.Y_AXIS));
        c.add(p0);
        jd.pack();
        jd.setVisible(true);
    }

    private static void addAndLeftAlign(JComponent parent, JComponent child){
        Box  b = Box.createHorizontalBox();
        b.add(child);
        b.add( Box.createHorizontalGlue() );
        parent.add(b);
    }
}