java - 将文本添加到我的 JScrollPane/JArea 时如何自动滚动？

Question

我在一个小应用程序中有一个 JTextArea，它显示所有异常 e.getMessage 和其他内容。但是，JScrollPane 不显示最新结果。我必须手动滚动它才能看到刚刚发生的事情。

我希望它与 Eclipse 控制台完全一样

如何设置光标？

这是我的代码

publiv void createGUI)( {

                JTextArea progress = new JTextArea("");

        JScrollPane jsp = new JScrollPane(progress);
        jsp.setBounds(320, 10, 280, 300); 
        j.add(jsp) ;

        JScrollBar max = jsp.getVerticalScrollBar() ;
        max.setValue(max.getMaximum() ) ;        // I tried this as suggested by Yasmani Llanes, but it did not work
...

Answer 1

尝试在文本末尾设置插入符位置:

progress.setCaretPosition(progress.getText().length()) 

以下示例适用于我:

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

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;


public class Test extends JFrame {
    private JTextArea txtTest;

    Test() {
        this.setSize(500, 300);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setLayout(new BorderLayout());

        JScrollPane pane = new JScrollPane();
        txtTest = new JTextArea();
        pane.setViewportView(txtTest);
        this.add(pane, BorderLayout.CENTER);

        JButton btnAddText = new JButton("Add Text");
        btnAddText.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                txtTest.setText(txtTest.getText() + "\nLorem ipsum dolor sit amet, consectetur adipiscing elit. Morbi sagittis id nibh vel rhoncus. ");

                String text = txtTest.getText();

                txtTest.setCaretPosition(text != null ? text.length() : 0);
            }
        });
        this.add(btnAddText, BorderLayout.SOUTH);

        this.setVisible(true);
    }

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