Question

我想让一个组件占用Container的maximumAvailableHeight。例如，在我下面粘贴的代码中，我将根框架设置为800,600。我想设置只有那个帧的高度/宽度（我不想尝试像素化它的孩子）。如果我运行它，我会看到一个严重对齐的UI。

首先，我想要一个面板（在根框架内）占据框架的100％高度（在这种情况下，800px减去绘制框架标题所需的小空间）。

其次，在面板内我有一个树和文本区域。我希望他们两个都采取100％的高度，让树占30％，textArea采取70％的宽度（如果树扩展到10级，那么我可以使用ScrollPane）。

了解这在HTML中最容易实现。只说高度= 100％，宽度为30％等我们就完成了。有人知道这是否可以在Swing中完成？（我可以通过设置像素高度和布局管理器来实现这一目标，但我正在寻找设置百分比高度和宽度的最干净的解决方案。）

package com.ekanathk.logger.gui;

import javax.swing.*;
import javax.swing.tree.DefaultMutableTreeNode;

public class TestFrame extends JFrame {
    public TestFrame() {
        super("Top Frame");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        JPanel panel = new JPanel();
        JTree env = getEnvironmentTree();
        env.expandRow(0);
        panel.add(new JScrollPane(env));
        panel.add(new JTextArea("Some contents"));
        getContentPane().add(panel);
        setSize(800, 600);
        SwingUtil.centerComponentOnScreen(this);
        setVisible(true);
    }

    private JTree getEnvironmentTree() {
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
        JTree tree = new JTree(root);
        DefaultMutableTreeNode one = new DefaultMutableTreeNode("One");
        root.add(one);
        one.add(new DefaultMutableTreeNode("under one.1"));
        one.add(new DefaultMutableTreeNode("under one.2"));
        root.add(new DefaultMutableTreeNode("two"));
        root.add(new DefaultMutableTreeNode("three"));
        return tree;
    }

    public static void main(String[] args) {
        new TestFrame();
    }
}

Answer 1

这使用GridBagLayout来做你想要的事情。您可以使用组件的setMinimumSize和setPreferedSize。

import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.*;
import javax.swing.tree.DefaultMutableTreeNode;

public class TestFrame extends JFrame {
    private static final long serialVersionUID = 1L;

    public TestFrame()  {
        super("Top Frame");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        JPanel panel = new JPanel(new GridBagLayout());

        JTree env = getEnvironmentTree();
        env.expandRow(0);

        GridBagConstraints c = new GridBagConstraints();
        c.fill = GridBagConstraints.BOTH;
        c.weightx=.7;
        c.weighty=1;

        c.gridx=0;
        c.gridy=0;
        c.gridheight=1;
        c.gridwidth=7;
        panel.add(new JScrollPane(env),c);

        c.weightx=.3;
        c.gridx=7;
        c.gridy=0;
        c.gridheight=1;
        c.gridwidth=GridBagConstraints.REMAINDER;
        panel.add(new JTextArea("Some contents"),c);

        add(panel);
        setSize(800, 600);
        setLocationRelativeTo(null);
        setVisible(true);
    }

    private JTree getEnvironmentTree() {
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
        JTree tree = new JTree(root);
        DefaultMutableTreeNode one = new DefaultMutableTreeNode("One");
        root.add(one);
        one.add(new DefaultMutableTreeNode("under one.1"));
        one.add(new DefaultMutableTreeNode("under one.2"));
        root.add(new DefaultMutableTreeNode("two"));
        root.add(new DefaultMutableTreeNode("three"));
        return tree;
    }

    public static void main(String[] args) {
        new TestFrame();
    }
}

Answer 2

有许多layout managers可以实现这一目标 - GridLayout（1x1网格），GridBagLayout，也许是BorderLayout。

Answer 3

这是使用SpringLayout的另一种方法。我无法使Spring.width和Spring.height工作，所以我使用了更详细的方式

import java.awt.BorderLayout;
import java.awt.Color;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTree;
import javax.swing.Spring;
import javax.swing.SpringLayout;
import javax.swing.tree.DefaultMutableTreeNode;

public class TestFrame extends JFrame {
    private static final long serialVersionUID = 1L;

    public TestFrame()  {
        super("Top Frame");
        setDefaultCloseOperation(EXIT_ON_CLOSE);        
        SpringLayout layout = new SpringLayout();
        JTree env = getEnvironmentTree();
        env.expandRow(0);
        JPanel contentPane = new JPanel(layout);
        contentPane.setLayout(layout);
        JScrollPane treePane = new JScrollPane(env);
        JTextArea area = new JTextArea("Some contents");
        contentPane.add(treePane);
        contentPane.add(area);        
        setLayout(new BorderLayout());
        add(contentPane);
        setSize(800, 600);

        SpringLayout.Constraints  cons;
        cons = layout.getConstraints(treePane);
        cons.setX(Spring.constant(0));
        cons.setY(Spring.constant(0));
        cons.setWidth(Spring.scale(layout.getConstraint(SpringLayout.EAST, contentPane), .7f));
        cons.setHeight(layout.getConstraint(SpringLayout.SOUTH, contentPane));

        cons = layout.getConstraints(area);
        cons.setX(layout.getConstraint(SpringLayout.EAST, treePane));
        cons.setY(Spring.constant(0));
        cons.setWidth(Spring.scale(layout.getConstraint(SpringLayout.EAST, contentPane), .3f));
        cons.setHeight(layout.getConstraint(SpringLayout.SOUTH, contentPane));
        setPreferredSize(getSize());
        setLocationRelativeTo(null);
        pack();
        setVisible(true);
    }

    private JTree getEnvironmentTree() {
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
        JTree tree = new JTree(root);
        DefaultMutableTreeNode one = new DefaultMutableTreeNode("One");
        root.add(one);
        one.add(new DefaultMutableTreeNode("under one.1"));
        one.add(new DefaultMutableTreeNode("under one.2"));
        root.add(new DefaultMutableTreeNode("two"));
        root.add(new DefaultMutableTreeNode("three"));
        return tree;
    }

    public static void main(String[] args) {
        new TestFrame();
    }
}

Swing：如何将组件高度设置为容器的高度？

3 个答案: