java - 中心 JTEXTAREA 网格袋

Question

我希望将我在摇摆应用程序底部的 JTextArea 居中。我一直在玩 gridbag 布局的坐标，但似乎无法弄清楚如何扩展 JTEXT AREA 以填充回车按钮下的空间。

package guiprojj;

import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Map;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;

import com.json.parsers.JSONParser;
import com.json.parsers.JsonParserFactory;


public class gui {
    public static void main(String[] args)
    {
        JFrame maingui = new JFrame("Gui");
        maingui.setLayout(new GridBagLayout());
        GridBagConstraints c = new GridBagConstraints();
        c.fill = GridBagConstraints.VERTICAL;
        JButton enter = new JButton("Enter");
        c.gridx = 2;
        c.gridy = 1;
        maingui.add(enter, c);
        final JTextArea movieinfo = new JTextArea(5,20);
        movieinfo.setBorder(BorderFactory.createMatteBorder(2,2,2,2,Color.red));
        final JTextField movietext = new JTextField(18);
        c.gridx = 1;
        c.gridy = 1;
        maingui.add(movietext, c);
        final JScrollPane scrolll = new JScrollPane(movieinfo);
        c.gridx = 1;
        c.gridy = 4;
        maingui.add(scrolll, c);

        final JLabel titlee = new JLabel("Enter movie name below!");
        c.gridx = 1;
        c.gridy = 0;
        maingui.add(titlee, c);
        maingui.setResizable(false);
        maingui.setVisible(true);
        movieinfo.setLineWrap(true);
        movieinfo.setWrapStyleWord(true);
        movieinfo.setEditable(false);

        scrolll.getPreferredSize();
        //pangui.setPreferredSize(new Dimension(300, 150));
        //pangui.add(scrolll, BorderLayout.CENTER);
        //movieinfo.add(scrolll);
        maingui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        maingui.pack();
        enter.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e)  
            {
                System.out.println(Test.getMovieInfo(movietext.getText()));
                 JsonParserFactory factory=JsonParserFactory.getInstance();
                 JSONParser parser=factory.newJsonParser();
                 Map jsonData=parser.parseJson(Test.getMovieInfo(movietext.getText()));
                 String Title = (String)jsonData.get("Title");
                 String Year = (String)jsonData.get("Year");
                 String Plot = (String)jsonData.get("Plot");
                 movieinfo.setText("Title: "+Title+"\nYear: "+ Year +"\nPlot: "+Plot);
            }
            });

        }
}

Answer 1

• 使用未指定行数和列数的构造函数JTextArea
• 为to设置fill属性GridBagConstraintsBOTH
• 为沿 Y 轴扩展设置非零值weighty，例如c.weighty = 1

Answer 2

您可以通过添加网格宽度约束来实现它，如下所示：

    final JScrollPane scrolll = new JScrollPane(movieinfo);
    c.gridx = 1;
    c.gridy = 4;
    c.gridwidth = 2;
    maingui.add(scrolll, c);