Question

我在JProgressBar gui上使用Swing：

当我使用progressBar.setValue()进行更新时最小化窗口时，它会像这样挤压：

请注意，调整大小或类似内容并不能解决问题。

为什么会发生以及如何预防呢？是什么导致的？我希望进度条与第一张图像保持相同的大小。

我正在使用GridBagLayout。

重现的代码：

import javax.swing.JFrame;
import javax.swing.SwingWorker;

import java.awt.Dimension;
import java.awt.GridBagLayout;

import javax.swing.JProgressBar;

import java.awt.GridBagConstraints;

import javax.swing.JButton;

import java.awt.Insets;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

import javax.swing.JLabel;
import javax.swing.JTextArea;
import javax.swing.JScrollPane;

@SuppressWarnings("serial")
public class ProgressBarSqueezeFixedExample extends JFrame
{
    public ProgressBarSqueezeFixedExample()
    {
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setSize(500, 500);
        GridBagLayout gridBagLayout = new GridBagLayout();
        gridBagLayout.columnWidths = new int[] { 0, 0, 0 };
        gridBagLayout.rowHeights = new int[] { 0, 0, 0, 0, 0 };
        gridBagLayout.columnWeights = new double[] { 1.0, 0.0, Double.MIN_VALUE };
        gridBagLayout.rowWeights = new double[] { 0.0, 0.0, 0.0, 1.0,
                Double.MIN_VALUE };
        getContentPane().setLayout(gridBagLayout);

        JProgressBar progressBar = new JProgressBar();

        JTextArea textArea = new JTextArea();

        JButton btnRun = new JButton("Run");
        setPreferredSize(new Dimension(200, 200));

        btnRun.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent arg0)
            {
                SwingWorker<String, String> worker = new SwingWorker<String, String>()
                {
                    @Override
                    protected String doInBackground() throws Exception
                    {
                        for (int i = 0; i < 10001; i++)
                        {
                            try
                            {
                                Thread.sleep(1);
                            } catch (InterruptedException e)
                            {
                                e.printStackTrace();
                            }

                            progressBar.setValue(i);
                            progressBar.setString(i + " %");

                            textArea.append(i + System.lineSeparator());
                        }

                        return null;
                    }
                };

                worker.execute();
            }
        });
        GridBagConstraints gbc_btnRun = new GridBagConstraints();
        gbc_btnRun.insets = new Insets(0, 0, 5, 5);
        gbc_btnRun.gridx = 0;
        gbc_btnRun.gridy = 0;
        getContentPane().add(btnRun, gbc_btnRun);

        JLabel lblProgress = new JLabel("Progress");
        GridBagConstraints gbc_lblProgress = new GridBagConstraints();
        gbc_lblProgress.insets = new Insets(0, 0, 5, 5);
        gbc_lblProgress.gridx = 0;
        gbc_lblProgress.gridy = 1;
        getContentPane().add(lblProgress, gbc_lblProgress);

        progressBar.setMaximum(10000);
        progressBar.setStringPainted(true);
        progressBar.setMinimumSize(progressBar.getPreferredSize()); // Fixes squeezing issues

        GridBagConstraints gbc_progressBar = new GridBagConstraints();
        gbc_progressBar.insets = new Insets(0, 0, 5, 5);
        gbc_progressBar.gridx = 0;
        gbc_progressBar.gridy = 2;
        getContentPane().add(progressBar, gbc_progressBar);

        JScrollPane scrollPane = new JScrollPane();
        GridBagConstraints gbc_scrollPane = new GridBagConstraints();
        gbc_progressBar.fill=GridBagConstraints.HORIZONTAL; // Alternate fix
        gbc_scrollPane.gridwidth = 2;
        gbc_scrollPane.fill = GridBagConstraints.BOTH;
        gbc_scrollPane.gridx = 0;
        gbc_scrollPane.gridy = 3;
        getContentPane().add(scrollPane, gbc_scrollPane);

        scrollPane.setViewportView(textArea);
        pack();

        setVisible(true);
    }

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

gui的大小调整和压缩进度条必须使用textArea append（）看起来如何。

Answer 1

使用组件显示区域大于组件请求大小时使用的GridBagConstraints#fill属性。它决定是否调整组件大小。

gbc_progressBar.fill=GridBagConstraints.HORIZONTAL;

注意：无需创建GridBagConstraints的多个实例。你也可以使用单个对象来实现同样的目标。

详细了解How to Use GridBagLayout并查看示例。

JProgressBar不正确地获取压缩/调整大小

1 个答案: