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所以，我在滚动窗格中有一堆文本字段。当用户关注底部的最后一个时，会添加更多文本字段。我的问题是，我怎样才能让滚动窗格滚动到焦点文本字段？我的意思是，用户将按 TAB 或 ENTER 键跳转到下一个文本字段，但如果不滚动自己，他将无法看到它。当最后一个文本字段具有焦点时，我可以模拟按下向下箭头或 PageDown 但这会很难看，即使它会做我需要的事情。

我通过搜索找到了类似的东西，但我无法让它工作。

public void focusGained(FocusEvent e) {
            currentview = t1;
            int cons = i - 1;
             Rectangle r = new Rectangle(t1.getX(), t1.getY(), 1, 1);
            jScrollPane1.scrollRectToVisible(r);
            if (t1.getName().equals("prod" + cons)) {

                newproduct();
            };

        }
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2 回答 2

2

Two things arise.

Firstly, JTextField#scrollRectToVisible has being overridden and does something slightly different from other components...annoying....

Secondly, you need to be converting the fields location relative to the it's parent and then using the parent's scrollRectToVisible method, for example...

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Rectangle;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class ScrollFocusedField {

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

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

                FocusAdapter fh = new FocusAdapter() {

                    @Override
                    public void focusGained(FocusEvent e) {
                        JComponent comp = (JComponent) e.getComponent();
                        System.out.println("FocusGained");
                        Rectangle bounds = comp.getBounds();
                        bounds.setLocation(SwingUtilities.convertPoint(comp, bounds.getLocation(), comp.getParent()));

                        JComponent parent = (JComponent) comp.getParent();
                        parent.scrollRectToVisible(comp.getBounds());
                    }

                };

                JPanel panel = new JPanel(new GridBagLayout());
                GridBagConstraints gbc = new GridBagConstraints();
                for (int index = 0; index < 100; index++) {
                    gbc.fill = GridBagConstraints.NONE;
                    gbc.weightx = 0;
                    gbc.gridx = 0;
                    gbc.gridy = index;
                    panel.add(new JLabel(Integer.toString(index)), gbc);

                    JTextField field = new JTextField();
                    field.addFocusListener(fh);
                    gbc.fill = GridBagConstraints.HORIZONTAL;
                    gbc.weightx = 1;
                    gbc.gridx = 1;
                    panel.add(field, gbc);
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new JScrollPane(panel));
                frame.setSize(200, 400);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

}
于 2013-12-11T01:48:27.997 回答
2

查看FormScroller。它是一个简单的类，您可以使用它来确保当您切换到组件时该组件是可见的。FormScroller 可以与任何滚动窗格一起使用，无需将 FocusListeners 添加到表单上的每个组件。

它提供了一些选项，可让您准确控制滚动的工作方式。

于 2013-12-11T01:59:11.950 回答