Question

我是这里的新程序员，我有一些要问的问题，我已将图片浏览到我的GUI（并在文本框中设置路径），该图片显示在标签上，但标签尺寸仅设置为100,100而图片要大得多，所以当我打开/显示它的标签时会被裁剪，无论如何都要自动调整大小到标签大小？下面是我在浏览按钮和打开对话框中的逻辑代码请任何人告诉我我错在哪里..

public class ImagePath extends javax.swing.JFrame {
    private JPanel contentPane;

    JLabel jLabel1;
    String s2;
    File targetFile;
    BufferedImage targetImg;

    public ImagePath() {
        initComponents();
    }

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {

        JFileChooser jFileChooser1 = new JFileChooser();

        int state = jFileChooser1.showOpenDialog(new JFrame());

        jTextField1.setText("");
        if (state == JFileChooser.APPROVE_OPTION) {
            JOptionPane.showMessageDialog(new JFrame(), "hii");
            File file = jFileChooser1.getSelectedFile();
            s2 = file.toString();
            jTextField1.setText(s2);
            jLabel1 = new JLabel();
            jLabel1.setName(s2);
            jLabel1.setLocation(50, 50);
            jLabel1.setSize(300, 300);
            add(jLabel1);
            BufferedImage bi1;

            try {
                bi1 = ImageIO.read(file);
                ImageIcon icon1 = new ImageIcon(bi1);
                jLabel1.setIcon(icon1);

                Image img = icon1.getImage();
                ImageIcon icon = new ImageIcon(file.getPath());
                Image scaleImage = icon.getImage().getScaledInstance(28, 28, Image.SCALE_DEFAULT);

                repaint();
                pack();

            } catch (Exception e) {
                System.out.println(e);
            }
        } else if (state == JFileChooser.CANCEL_OPTION) {
            JOptionPane.showMessageDialog(new JFrame(), "Canceled");
        }

    }

}

Answer 1

除非你真的想要一个讨厌的头痛，否则我建议你利用布局管理系统。

不要试图设置组件的大小和位置，而是让他们决定如何在可能的情况下显示它们。

虽然我个人利用Netbeans表单设计器，但我鼓励您花时间学习如何手动构建UI，它将为表单设计人员可以做的事情提供更好的应用，以及您可以提供的想法员工制作高级用户界面 - 恕我直言

enter image description here

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;

public class SimpleImageBrowser {

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

    public SimpleImageBrowser() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new SimpleImageBrowser.ImageBrowserPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class ImageBrowserPane extends JPanel {

        private JFileChooser fcImage = new JFileChooser();
        private SimpleImageBrowser.ImagePane imagePane;

        public ImageBrowserPane() {
            setLayout(new BorderLayout());

            imagePane = new SimpleImageBrowser.ImagePane();
            add(new JScrollPane(imagePane));

            JButton add = new JButton("Add");
            add.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {

                    int state = fcImage.showOpenDialog(SimpleImageBrowser.ImageBrowserPane.this);
                    switch (state) {

                        case JFileChooser.APPROVE_OPTION:
                            File file = fcImage.getSelectedFile();

                            try {
                                BufferedImage bi1 = ImageIO.read(file);
                                ImageIcon icon1 = new ImageIcon(bi1);
                                JLabel label = new JLabel(icon1);
                                label.setText(file.getPath());
                                label.setHorizontalTextPosition(JLabel.CENTER);
                                label.setVerticalTextPosition(JLabel.BOTTOM);
                                label.setForeground(Color.WHITE);
                                label.setBorder(new LineBorder(Color.WHITE));
                                imagePane.add(label);
                                imagePane.revalidate();
                            } catch (Exception exp) {
                                exp.printStackTrace();
                            }
                    }
                }
            });

            JPanel buttons = new JPanel();
            buttons.add(add);
            add(buttons, BorderLayout.NORTH);

        }
    }

    public class ImagePane extends JPanel {

        public ImagePane() {
            setLayout(new SimpleImageBrowser.WrapLayout());
            setBackground(Color.BLACK);
        }

        @Override
        public Dimension getPreferredSize() {
            return getComponentCount() == 0 ? new Dimension(200, 200) : super.getPreferredSize();
        }
    }

    /**
     * FlowLayout subclass that fully supports wrapping of components.
     */
    public class WrapLayout extends FlowLayout {

        private Dimension preferredLayoutSize;

        /**
         * Constructs a new
         * <code>WrapLayout</code> with a left alignment and a default 5-unit
         * horizontal and vertical gap.
         */
        public WrapLayout() {
            super();
        }

        /**
         * Constructs a new
         * <code>FlowLayout</code> with the specified alignment and a default 5-unit
         * horizontal and vertical gap. The value of the alignment argument must be
         * one of
         * <code>WrapLayout</code>,
         * <code>WrapLayout</code>, or
         * <code>WrapLayout</code>.
         *
         * @param align the alignment value
         */
        public WrapLayout(int align) {
            super(align);
        }

        /**
         * Creates a new flow layout manager with the indicated alignment and the
         * indicated horizontal and vertical gaps.
         * <p>
         * The value of the alignment argument must be one of
         * <code>WrapLayout</code>,
         * <code>WrapLayout</code>, or
         * <code>WrapLayout</code>.
         *
         * @param align the alignment value
         * @param hgap the horizontal gap between components
         * @param vgap the vertical gap between components
         */
        public WrapLayout(int align, int hgap, int vgap) {
            super(align, hgap, vgap);
        }

        /**
         * Returns the preferred dimensions for this layout given the
         * <i>visible</i> components in the specified target container.
         *
         * @param target the component which needs to be laid out 
         * @return the preferred dimensions to lay out the subcomponents of the
         * specified container
         */
        @Override
        public Dimension preferredLayoutSize(Container target) {
            return layoutSize(target, true);
        }

        /**
         * Returns the minimum dimensions needed to layout the <i>visible</i>
         * components contained in the specified target container.
         *
         * @param target the component which needs to be laid out
         * @return the minimum dimensions to lay out the subcomponents of the
         * specified container
         */
        @Override
        public Dimension minimumLayoutSize(Container target) {
            Dimension minimum = layoutSize(target, false);
            minimum.width -= (getHgap() + 1);
            return minimum;
        }

        /**
         * Returns the minimum or preferred dimension needed to layout the target
         * container.
         *
         * @param target target to get layout size for
         * @param preferred should preferred size be calculated
         * @return the dimension to layout the target container
         */
        private Dimension layoutSize(Container target, boolean preferred) {
            synchronized (target.getTreeLock()) {
                //  Each row must fit with the width allocated to the containter.
                //  When the container width = 0, the preferred width of the container
                //  has not yet been calculated so lets ask for the maximum.

                int targetWidth = target.getSize().width;

                if (targetWidth == 0) {
                    targetWidth = Integer.MAX_VALUE;
                }

                int hgap = getHgap();
                int vgap = getVgap();
                Insets insets = target.getInsets();
                int horizontalInsetsAndGap = insets.left + insets.right + (hgap * 2);
                int maxWidth = targetWidth - horizontalInsetsAndGap;

                //  Fit components into the allowed width

                Dimension dim = new Dimension(0, 0);
                int rowWidth = 0;
                int rowHeight = 0;

                int nmembers = target.getComponentCount();

                for (int i = 0; i < nmembers; i++) {
                    Component m = target.getComponent(i);

                    if (m.isVisible()) {
                        Dimension d = preferred ? m.getPreferredSize() : m.getMinimumSize();

                        //  Can't add the component to current row. Start a new row.

                        if (rowWidth + d.width > maxWidth) {
                            addRow(dim, rowWidth, rowHeight);
                            rowWidth = 0;
                            rowHeight = 0;
                        }

                        //  Add a horizontal gap for all components after the first

                        if (rowWidth != 0) {
                            rowWidth += hgap;
                        }

                        rowWidth += d.width;
                        rowHeight = Math.max(rowHeight, d.height);
                    }
                }

                addRow(dim, rowWidth, rowHeight);

                dim.width += horizontalInsetsAndGap;
                dim.height += insets.top + insets.bottom + vgap * 2;

                //    When using a scroll pane or the DecoratedLookAndFeel we need to
                //  make sure the preferred size is less than the size of the
                //  target containter so shrinking the container size works
                //  correctly. Removing the horizontal gap is an easy way to do this.

                Container scrollPane = SwingUtilities.getAncestorOfClass(JScrollPane.class, target);

                if (scrollPane != null && target.isValid()) {
                    dim.width -= (hgap + 1);
                }

                return dim;
            }
        }

        /*
         *  A new row has been completed. Use the dimensions of this row
         *  to update the preferred size for the container.
         *
         *  @param dim update the width and height when appropriate
         *  @param rowWidth the width of the row to add
         *  @param rowHeight the height of the row to add
         */
        private void addRow(Dimension dim, int rowWidth, int rowHeight) {
            dim.width = Math.max(dim.width, rowWidth);

            if (dim.height > 0) {
                dim.height += getVgap();
            }

            dim.height += rowHeight;
        }
    }
}

我已经包含了Rob Camick（潜伏在这个地方）的WrapLayout，因为坦率地说，其他布局经理都没有给我带来我想要的效果。

我还使用图像的路径设置标签的文本

查看Using layout Managers和A Visual Guide to Layout Managers

查看WrapLayout

更新了文字字段

如果您想将文字字段与图片相关联，那么我建议您将标签和文字字段添加到JPanel（使用BorderLayout之类的内容），然后将其添加到您的图片窗格......

enter image description here

public class ImagePane extends JPanel {

    public ImagePane() {
        setLayout(new SimpleImageBrowser.WrapLayout());
        setBackground(Color.BLACK);
    }

    public void addImage(File file) throws IOException {
        BufferedImage bi1 = ImageIO.read(file);
        ImageIcon icon1 = new ImageIcon(bi1);
        JPanel imgPane = new JPanel(new BorderLayout());
        imgPane.setOpaque(false);
        JLabel label = new JLabel(icon1);
        imgPane.add(label);
        JTextField field = new JTextField(file.getPath(), 20);
        field.setEditable(false);
        imgPane.add(field, BorderLayout.SOUTH);
        add(imgPane);
        revalidate();
    }

    @Override
    public Dimension getPreferredSize() {
        return getComponentCount() == 0 ? new Dimension(200, 200) : super.getPreferredSize();
    }
}

更新后的ActionListener ...

add.addActionListener(new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {

        int state = fcImage.showOpenDialog(SimpleImageBrowser.ImageBrowserPane.this);
        switch (state) {

            case JFileChooser.APPROVE_OPTION:
                File file = fcImage.getSelectedFile();
                try {
                    imagePane.addImage(file);
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
        }
    }
});

Answer 2

你应该切断对label.setSize的号召。您还应该将所有组件放在表单设计器中，而不是在单击按钮时生成它们。也许你还可以在讨价还价中添加布局管理器？这实际上将涉及对NetBeans的反抗。

java swing根据jLabel调整ImageIcon大小

2 个答案: