Question

我试图垂直对齐JPanel。 setAlignmentY未按预期工作。这是我到目前为止所做的。

import java.awt.Color;
import java.awt.Component;
import java.awt.GridLayout;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.LineBorder;

public class ValignJPanel {

    public static void main(String args[]) {
        JFrame frame = new JFrame("Vertical Alignment");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel panel1 = wrapPanel(createPanel(), Component.TOP_ALIGNMENT);
        JPanel panel2 = wrapPanel(createPanel(), Component.CENTER_ALIGNMENT);
        JPanel panel3 = wrapPanel(createPanel(), Component.BOTTOM_ALIGNMENT);

        frame.setLayout(new GridLayout(1, 3));
        frame.add(panel1);
        frame.add(panel2);
        frame.add(panel3);

        frame.setSize(400, 150);
        frame.setVisible(true);
    }

    private static JPanel wrapPanel(JPanel oldPanel, float alignment) {
        JPanel panel = new JPanel();
        oldPanel.setAlignmentY(alignment);
        panel.add(oldPanel);
        return panel;
    }

    private static JPanel createPanel() {
        JPanel panel = new JPanel();
        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
        panel.add(new JLabel("Hello world"));
        panel.add(new JTextField(10));
        panel.setBorder(new LineBorder(Color.red));
        return panel;
    }
}

我正在尝试创建一个包含JPanel＆amp;将它包装为给定的对齐方式。

编辑（来自评论，带图片）我想获得看起来像这样的输出，但是代替按钮，我想要JPanel

enter image description here

Answer 1

您需要做的是在BoxLayout方法中将new JPanel的布局设置为wrapPanel。

JPanel panel = new JPanel();
BoxLayout layout = new BoxLayout(panel, BoxLayout.LINE_AXIS);
panel.setLayout(layout);

错误：使用您当前的代码它似乎无法正常工作，因为它会拉伸文本字段。如果您使用JButton代替JTextFeild，您将看到效果。我还在试图找出文本字段为什么这样做。

更新与上述代码一起，解决文本字段扩展的问题，正如Camickr在this answer

中所回答的那样

BoxLayout是少数几个遵循组件最小和最大大小的布局管理器之一。因此，如果您想阻止面板拉伸，可以使用：

panel.setMaximumSize( panel.getPreferredSize() );

上面的代码是您想要放在createPanel方法中的代码。

enter image description here

import java.awt.Color;
import java.awt.Component;
import java.awt.GridLayout;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.LineBorder;

public class ValignJPanel {

    public static void main(String args[]) {
        JFrame frame = new JFrame("Vertical Alignment");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel panel1 = wrapPanel(createPanel(), Component.TOP_ALIGNMENT);
        JPanel panel2 = wrapPanel(createPanel(), Component.CENTER_ALIGNMENT);
        JPanel panel3 = wrapPanel(createPanel(), Component.BOTTOM_ALIGNMENT);

        frame.setLayout(new GridLayout(1, 3));
        frame.add(panel1);
        frame.add(panel2);
        frame.add(panel3);
        frame.setSize(400, 150);
        frame.setVisible(true);
    }

    private static JPanel wrapPanel(JPanel oldPanel, float alignment) {
        JPanel panel = new JPanel();
        BoxLayout layout = new BoxLayout(panel, BoxLayout.LINE_AXIS);
        panel.setLayout(layout);
        oldPanel.setAlignmentY(alignment);
        panel.add(oldPanel);
        return panel;
    }

    private static JPanel createPanel() {
        JPanel panel = new JPanel();
        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
        panel.add(new JLabel("Hello world"));
        panel.add(new JTextField(10));
        panel.setBorder(new LineBorder(Color.red));
        panel.setMaximumSize( panel.getPreferredSize());
        return panel;
    }
}

Valign JPanel没有工作

1 个答案: