白板的微信
JTextArea您可以设置using的高度(可见行数)setRows()。试试下面的例子。我从你的代码开始,做了一些改动。import javax.swing.*;import java.awt.*;public class ThreeLinesTextArea{ public static void main(String[] args) { JPanel pane = new JPanel(); // Change to GridBagLayout pane.setLayout(new GridBagLayout()); JTextField url = new JTextField("https:testin.com"); JTextField username = new JTextField("theDude"); JTextArea statement = new JTextArea("This statement can becomme very very very long :)"); statement.setLineWrap(true); statement.setWrapStyleWord(true); // Use setRows() to make text area have multiple lines statement.setRows(3); JScrollPane scrollPane = new JScrollPane(statement); //This line is removed. scrollPane is added at the end. //pane.add(scrollPane); pane.add(new JLabel("Enter url: "), new GridBagConstraints(0, 0, 1, 1, 1.0, 1.0, GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(2, 2, 2, 2), 0, 0)); pane.add(url, new GridBagConstraints(1, 0, 1, 1, 1.0, 1.0, GridBagConstraints.WEST, GridBagConstraints.HORIZONTAL, new Insets(2, 2, 2, 2), 0, 0)); pane.add(new JLabel("Enter username: "), new GridBagConstraints(0, 1, 1, 1, 1.0, 1.0, GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(2, 2, 2, 2), 0, 0)); pane.add(username, new GridBagConstraints(1, 1, 1, 1, 1.0, 1.0, GridBagConstraints.WEST, GridBagConstraints.HORIZONTAL, new Insets(2, 2, 2, 2), 0, 0)); pane.add(new JLabel("Enter password: "), new GridBagConstraints(0, 2, 1, 1, 1.0, 1.0, GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(2, 2, 2, 2), 0, 0)); pane.add(new JPasswordField(15), new GridBagConstraints(1, 2, 1, 1, 1.0, 1.0, GridBagConstraints.WEST, GridBagConstraints.HORIZONTAL, new Insets(2, 2, 2, 2), 0, 0)); pane.add(new JLabel("Enter statement: "), new GridBagConstraints(0, 3, 1, 1, 1.0, 1.0, GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(2, 2, 2, 2), 0, 0)); pane.add(scrollPane, new GridBagConstraints(1, 3, 1, 1, 1.0, 1.0, GridBagConstraints.WEST, GridBagConstraints.HORIZONTAL, new Insets(2, 2, 2, 2), 0, 0)); int option = JOptionPane.showConfirmDialog(null, pane, "Fill all the fields", JOptionPane.OK_CANCEL_OPTION, JOptionPane.INFORMATION_MESSAGE); }}输出: