scrollRectToVisible 不会将滚动窗格移动到顶部

Question

下面是我的代码的简化版本，用于说明问题。我希望 scrollRectToVisible 会将滚动条和滚动窗格移回顶部，但它仍位于底部。提前感谢您的任何建议。

package testing;

import javax.swing.SwingUtilities;

public class Testing {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new GUItest();
            }
        });
    }
}

package testing;

import java.awt.Dimension;
import java.awt.Rectangle;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JScrollPane;

public class GUItest extends JFrame {
    private JEditorPane myEditorPane;
    private JScrollPane myScrollPane;
    public GUItest() {
        myEditorPane = new JEditorPane();
        myScrollPane = new JScrollPane(myEditorPane);
        myScrollPane.setPreferredSize(new Dimension(400, 200));
        getContentPane().add(myScrollPane);
        myEditorPane.setContentType("text/html");
        myEditorPane.setText("<html>" + "test<br>test<br>test<br>test<br>test<br>test<br>test<br>test<br>test<br>test<br>test<br>test<br>" + "</html>");
        Rectangle rect = new Rectangle(1, 1, 1, 1);
        myEditorPane.scrollRectToVisible(rect);
        pack();
        setVisible(true);
    }
}

Answer 1

如果在 JFrame 可见后滚动 "in the next frame render cycle"，它会起作用：

import javax.swing.SwingUtilities;
import java.awt.Dimension;
import java.awt.Rectangle;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JScrollPane;

public class GUItest extends JFrame  {
    private JEditorPane myEditorPane;
    private JScrollPane myScrollPane;

    public GUItest(){
        myEditorPane = new JEditorPane(); 
        myScrollPane = new JScrollPane(myEditorPane);
        myScrollPane.setPreferredSize(new Dimension(400, 100));
        getContentPane().add(myScrollPane);
        myEditorPane.setContentType("text/html");
        myEditorPane.setText("<html>" + "test<br>test<br>test<br>test<br>test<br>test<br>test<br>test<br>test<br>test<br>test<br>test<br>" + "</html>");
        Rectangle rect = new Rectangle(1,1,1,1);
        pack();
        setVisible(true);

        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                myEditorPane.scrollRectToVisible(rect);
            }
        });
    }    


    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable(){
            public void run(){
                new GUItest();
            }
        });
    }
}

看起来 JFrame 必须是 valid/visible 才能发出滚动命令。

scrollRectToVisible 不会将滚动窗格移动到顶部

scrollRectToVisible doesn't move scrollpane to top

java

swing

jscrollpane