Java 更改附件组件在文件选择器中的位置

我在更改文件选择器中附件组件的位置时遇到问题

我在文件选择器的附件组件中设置了一个复选框，定制了一个“保存文件”对话框。但是复选框的位置不好，它真的很难看

我可以将附件组件移动到文件窗格下方吗？怎么做

或者，如果您有其他解决方案来做同样的事情，也欢迎

谢谢你们

我使用以下代码添加复选框：

JFileChooser fc = new JFileChooser(file)
JPanel accessory = new JPanel();
JCheckBox isOpenBox = new JCheckBox("Open file after saving");
accessory.setLayout(new BorderLayout());
accessory.add(isOpenBox, BorderLayout.SOUTH);
fc.setAccessory(accessory);

在此屏幕截图中，复选框的位置不好

这个截图正是我想要的效果

正确的方法是构建一个新的UI/外观委托，以满足您的需求。问题是，您需要执行此操作的详细信息（以面向对象的方式）被隐藏，或者是

private

，没有公共/受保护的访问器，或者是本地定义的访问器…这是大多数L&F代表的一个主要问题…谢谢大家

所以，你最终会复制和粘贴整个类，这样你就可以添加这一个功能…你需要为你想要支持的每个平台都这样做

“不太理想”的方法是在

JFileChooser

中搜索并提取那些需要“改进”需求的元素。这是混乱的，它容易出错，它会做出假设，并且会非常非常容易地被打破

就个人而言，如果我要走这条特殊的道路，我会创建一个实用程序类，它提供一个简单的

public

，

static

方法，允许我传递

JFileChooser

的一个实例，并基于当前平台（和/或当前外观）拥有它，为我做更改…或者一个工厂类，它可以自动生成一个

JFileChooser

修改以满足这些要求…但这只是一个想法

让我再重复一遍，对于一个非常糟糕的设计问题来说，这是一个非常糟糕的想法，旨在证明：1-试图修改外观和感觉的问题；2-你在试图以你希望的方式完成这项工作时将面临的问题

import java.awt.Component;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFileChooser;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test {

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

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

                JFileChooser fc = new JFileChooser();
                List<JTextField> fields = findAll(JTextField.class, fc);
                if (fields.size() == 1) {
                    JTextField fieldNameField = fields.get(0);
                    Container parent = fieldNameField.getParent();
                    JCheckBox cb = new JCheckBox("Open file after saving");

                    JComboBox fileTypes = findAll(JComboBox.class, parent).get(0);

                    parent.setLayout(new GridBagLayout());
                    parent.removeAll();
                    GridBagConstraints gbc = new GridBagConstraints();
                    gbc.gridx = 0;
                    gbc.gridy = 0;
                    gbc.fill = GridBagConstraints.HORIZONTAL;
                    gbc.weightx = 1;
                    gbc.insets = new Insets(2, 2, 4, 2);

                    parent.add(fieldNameField, gbc); // file name field...

                    gbc.gridx++;
                    gbc.weightx = 0;
                    parent.add(cb, gbc); // Check box

                    gbc.gridx = 0;
                    gbc.gridy++;
                    gbc.gridwidth = GridBagConstraints.REMAINDER;
                    parent.add(fileTypes, gbc); // File types

                } else {
                    System.out.println("Found to many results?!");
                }

                fc.showOpenDialog(null);
            }
        });
    }

    public <T extends Component> List<T> findAll(Class<? extends T> aClass, Container parent) {
        List<T> matches = new ArrayList<>();

        for (Component child : parent.getComponents()) {
            if (aClass.isInstance(child)) {
                matches.add((T)child);
            }
            if (child instanceof Container) {
                matches.addAll(findAll(aClass, (Container)child));
            }
        }

        return matches;
    }

}

用反射更新…

由于我已经为之前的“hacks”下了地狱，我不妨加入一个使用反射查找字段的示例

现在，有很多方法可以做到这一点，例如，可以按类型列出所有字段，并检查各种属性以确定所需内容。如果您不知道实际的字段名，或者如果您可以访问源代码，可以直接查找字段名，如本例所示

import java.awt.Component;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.plaf.FileChooserUI;

public class Test1 {

    public static void main(String[] args) {
        new Test1();
    }

    public Test1() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFileChooser fc = new JFileChooser();
                JCheckBox cb = new JCheckBox("Open file after saving");

                if (System.getProperty("os.name").startsWith("Windows 7")) {

                    try {
                        JTextField filenameTextField = (JTextField) getField("filenameTextField", fc.getUI());
                        JComboBox filterComboBox = (JComboBox) getField("filterComboBox", fc.getUI());

                        System.out.println(filenameTextField);
                        System.out.println(filterComboBox);

                        Container parent = filenameTextField.getParent();

                        parent.setLayout(new GridBagLayout());
                        parent.removeAll();
                        GridBagConstraints gbc = new GridBagConstraints();
                        gbc.gridx = 0;
                        gbc.gridy = 0;
                        gbc.fill = GridBagConstraints.HORIZONTAL;
                        gbc.weightx = 1;
                        gbc.insets = new Insets(2, 2, 4, 2);

                        parent.add(filenameTextField, gbc); // file name field...

                        gbc.gridx++;
                        gbc.weightx = 0;
                        parent.add(cb, gbc); // Check box

                        gbc.gridx = 0;
                        gbc.gridy++;
                        gbc.gridwidth = GridBagConstraints.REMAINDER;
                        parent.add(filterComboBox, gbc); // File types                        
                    } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException ex) {
                        ex.printStackTrace();
                    }
                } else if (System.getProperty("os.name").startsWith("Mac OS X")) {

                    try {
                        JComboBox filterComboBox = (JComboBox) getField("filterComboBox", fc.getUI());
                        Container parent = filterComboBox.getParent();
                        parent.add(cb);
                    } catch (NoSuchFieldException | IllegalArgumentException | IllegalAccessException ex) {
                        ex.printStackTrace();
                    }
                }

                fc.showOpenDialog(null);
            }

        });
    }

    private Object getField(String name, Object parent) throws NoSuchFieldException, IllegalArgumentException, IllegalAccessException {
        Class aClass = parent.getClass();
        Field field = aClass.getDeclaredField(name);
        field.setAccessible(true);
        return field.get(parent);
    }

}

---

记住：仅仅因为你能做某事，并不意味着你应该做

您需要创建UI委托并从头开始重建UI。然后，您将需要为您想要支持的每个平台提供一个代理，以确保它不会在不同的平台上完全出错。在

基本文件选择器UI

中迁移，显然它没有对UI设置进行核心选择。仔细查看

WindowsFileChooserUI

，您可能需要的所有字段/容器实际上都是

private

或创建的locally@MadProgrammer谢谢，但听起来很复杂。我不知道如何构建UI委托，所以有没有更简单的方法？再次感谢：）@AnpingWang简短的回答是“不”，这不是一个非常重要的问题portable@MadProgrammer好的，谢谢。如果我们必须使用代理的东西，我怎么做？你能提供一些示例代码吗？或者一些外部链接也不错。谢谢你真的需要了解这种方法的危险性，它是一种肮脏的、肮脏的黑客行为，是由对当前界面设计的假设构成的……非常非常小心，我明白了。非常感谢你。它给了我一个解决这个问题的好主意。我会做更多的研究。非常感谢。在尝试查找

JComboBox

父项时，在

com.apple.laf.AquaLookAndFeel

上抛出

IndexOutOfBoundsException

；脆性指数高：：-）@垃圾天啊，可能不在同一条线上container@trashgod仅仅因为我已经进入（或已经进入）程序员的地狱，我用反射做了一个版本。。。

import java.awt.Component;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test1 {

    public static void main(String[] args) {
        new Test1();
    }

    public Test1() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFileChooser fc = new JFileChooser();        
                JCheckBox cb = new JCheckBox("Open file after saving");

                if (System.getProperty("os.name").startsWith("Windows 7")) {
                    List<JTextField> fields = findAll(JTextField.class, fc);
                    if (fields.size() == 1) {
                        JTextField fieldNameField = fields.get(0);
                        Container parent = fieldNameField.getParent();
                        JComboBox fileTypes = findAll(JComboBox.class, parent).get(0);

                        parent.setLayout(new GridBagLayout());
                        parent.removeAll();
                        GridBagConstraints gbc = new GridBagConstraints();
                        gbc.gridx = 0;
                        gbc.gridy = 0;
                        gbc.fill = GridBagConstraints.HORIZONTAL;
                        gbc.weightx = 1;
                        gbc.insets = new Insets(2, 2, 4, 2);

                        parent.add(fieldNameField, gbc); // file name field...

                        gbc.gridx++;
                        gbc.weightx = 0;
                        parent.add(cb, gbc); // Check box

                        gbc.gridx = 0;
                        gbc.gridy++;
                        gbc.gridwidth = GridBagConstraints.REMAINDER;
                        parent.add(fileTypes, gbc); // File types                        

                    }

                } else if (System.getProperty("os.name").startsWith("Mac OS X")) {

                    Locale l = fc.getLocale();
                    JLabel fileFormatLabel = findLabelByText(fc, UIManager.getString("FileChooser.filesOfTypeLabelText", l), "Format:");

                    if (fileFormatLabel != null) {
                        Container parent = fileFormatLabel.getParent();
                        System.out.println("");

                        parent.add(cb);
                    }

                }

                fc.showOpenDialog(null);
            }
        });
    }

    public JLabel findLabelByText(Container parent, String... texts) {
        JLabel find = null;
        List<JLabel> labels = findAll(JLabel.class, parent);
        for (JLabel label : labels) {
            for (String text : texts) {
                if (text.equals(label.getText())) {
                    find = label;
                    break;
                }
            }
        }
        return find;
    }

    public <T extends Component> List<T> findAll(Class<? extends T> aClass, Container parent) {
        List<T> matches = new ArrayList<>();

        for (Component child : parent.getComponents()) {
            if (aClass.isInstance(child)) {
                matches.add((T) child);
            }
            if (child instanceof Container) {
                matches.addAll(findAll(aClass, (Container) child));
            }
        }

        return matches;
    }

}

import java.awt.Component;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.plaf.FileChooserUI;

public class Test1 {

    public static void main(String[] args) {
        new Test1();
    }

    public Test1() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFileChooser fc = new JFileChooser();
                JCheckBox cb = new JCheckBox("Open file after saving");

                if (System.getProperty("os.name").startsWith("Windows 7")) {

                    try {
                        JTextField filenameTextField = (JTextField) getField("filenameTextField", fc.getUI());
                        JComboBox filterComboBox = (JComboBox) getField("filterComboBox", fc.getUI());

                        System.out.println(filenameTextField);
                        System.out.println(filterComboBox);

                        Container parent = filenameTextField.getParent();

                        parent.setLayout(new GridBagLayout());
                        parent.removeAll();
                        GridBagConstraints gbc = new GridBagConstraints();
                        gbc.gridx = 0;
                        gbc.gridy = 0;
                        gbc.fill = GridBagConstraints.HORIZONTAL;
                        gbc.weightx = 1;
                        gbc.insets = new Insets(2, 2, 4, 2);

                        parent.add(filenameTextField, gbc); // file name field...

                        gbc.gridx++;
                        gbc.weightx = 0;
                        parent.add(cb, gbc); // Check box

                        gbc.gridx = 0;
                        gbc.gridy++;
                        gbc.gridwidth = GridBagConstraints.REMAINDER;
                        parent.add(filterComboBox, gbc); // File types                        
                    } catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException ex) {
                        ex.printStackTrace();
                    }
                } else if (System.getProperty("os.name").startsWith("Mac OS X")) {

                    try {
                        JComboBox filterComboBox = (JComboBox) getField("filterComboBox", fc.getUI());
                        Container parent = filterComboBox.getParent();
                        parent.add(cb);
                    } catch (NoSuchFieldException | IllegalArgumentException | IllegalAccessException ex) {
                        ex.printStackTrace();
                    }
                }

                fc.showOpenDialog(null);
            }

        });
    }

    private Object getField(String name, Object parent) throws NoSuchFieldException, IllegalArgumentException, IllegalAccessException {
        Class aClass = parent.getClass();
        Field field = aClass.getDeclaredField(name);
        field.setAccessible(true);
        return field.get(parent);
    }

}