java - 如何在 GridLayout 中设置组件的大小并在键入时展开 JTextArea？

Question

我正在创建一个聊天，但这并不重要。我还没有遇到任何问题，一切工作正常，但我想更改 UI 外观，以便用户可以拥有更大的 JTextArea，而不是占用比需要更多空间的按钮。另外，我想调整 JTextArea 的大小，而不是只在一行中写入多个文本。最后，我要感谢您花时间帮助我:D

目标:

• 设置 JLabel 或 JTextArea 的大小，使按钮保持较小。

• 当文本达到正确限制时展开 JLabel 并将其放入新行(有点像 WhatsApp)。

代码:

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JTextArea;
import javax.swing.BorderFactory;
import javax.swing.JLabel;
import javax.swing.JTextField;

class MyFirstChatSO extends JFrame {

  JLabel title;
  JTextArea messages;
  JTextField text;
  JButton send;

    public MyFirstChatSO () {
      setLayout(new BorderLayout(0,10));

        title = new JLabel("-Chat-");
          title.setHorizontalAlignment(JLabel.CENTER);
          title.setFont(new Font("Gabriola",Font.ITALIC,34));
        add(title, BorderLayout.NORTH);

        messages = new JTextArea();
          messages.setEnabled(false);
          messages.setBorder(BorderFactory.createLineBorder(new Color(168,168,168),2,true));
        add(messages, BorderLayout.CENTER);

        JPanel subPanel = new JPanel();
          subPanel.setLayout(new GridLayout(0,2));
            text = new JTextField();
          subPanel.add(text);
            send = new JButton("Send");
          subPanel.add(send);
        add(subPanel, BorderLayout.SOUTH);
    }

    public static void main(String[] args) {
        MyFirstChatSO chat = new MyFirstChatSO();
          chat.setSize(600,450);
          chat.setLocationRelativeTo(null);
          chat.setVisible(true);
          chat.setDefaultCloseOperation(EXIT_ON_CLOSE);
    }
}

If any other methods such as using different layoutsManagers are the solution it would be good to know about it.

再次失败，但这次使用 GridBagLayout (我不知道如何使用它，请帮助我):

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JTextArea;
import javax.swing.BorderFactory;
import javax.swing.JLabel;
import javax.swing.JTextField;

class MyFirstChatSO extends JFrame {

  JLabel title;
  JTextArea messages;
  JTextField text;
  JButton send;

    public MyFirstChatSO () {
      setLayout(new BorderLayout(0,10));

        title = new JLabel("-Chat-");
          title.setHorizontalAlignment(JLabel.CENTER);
          title.setFont(new Font("Gabriola",Font.ITALIC,34));
        add(title, BorderLayout.NORTH);

        messages = new JTextArea();
          messages.setEnabled(false);
          messages.setBorder(BorderFactory.createLineBorder(new Color(168,168,168),2,true));
        add(messages, BorderLayout.CENTER);

    JPanel subPanel = new JPanel();
      subPanel.setLayout(new GridBagLayout());
      GridBagConstraints gb = new GridBagConstraints();
      gb.weightx = 1;
      gb.weighty = 1;
      gb.fill = GridBagConstraints.HORIZONTAL;
        text = new JTextField();
        gb.gridx = 0;
        gb.gridy = 0;
        gb.gridwidth = 6;
        gb.fill = GridBagConstraints.HORIZONTAL;
      subPanel.add(text,gb);
        send = new JButton("Send");
        gb.gridx = 7;
        gb.gridy = 0;
      subPanel.add(send,gb);
    add(subPanel, BorderLayout.SOUTH);
    }

    public static void main(String[] args) {
        MyFirstChatSO chat = new MyFirstChatSO();
          chat.setSize(600,450);
          chat.setLocationRelativeTo(null);
          chat.setVisible(true);
          chat.setDefaultCloseOperation(EXIT_ON_CLOSE);
    }
}

Answer 1

Another fail, but this time with GridBagLayout (I don't know how to use it, help me pls):

是的，您需要了解它是如何工作的。一直有How to Use GridBagLayout以及可用的 JavaDocs ;)

所以，我从...开始

JPanel subPanel = new JPanel(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.weightx = 1;
gbc.weighty = 1;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.insets = new Insets(4, 4, 4, 4);

text = new JTextArea(1, 80);
text.setBorder(new CompoundBorder(new LineBorder(Color.DARK_GRAY), new EmptyBorder(4, 4, 4, 4)));
subPanel.add(text, gbc);

gbc.insets = new Insets(0, 0, 0, 0);
gbc.weightx = 0;
gbc.weighty = 0;
gbc.fill = GridBagConstraints.HORIZONTAL;
send = new JButton("Send");
subPanel.add(send, gbc);

我最终得到了类似的东西......

但是等一下，这个示例使用的是 JTextArea？!为什么!？

啊，那是因为我是一条鬼鬼祟祟、作弊的裤子;)

通过这种方式使用JTextArea，您可以免费获得一个自动扩展文本字段。现在，重要的是要记住，这是不受约束的，这意味着用户可以继续按 Enter 并使 JTextArea 填充越来越多的空间。

要解决这个问题会变得很复杂，我会研究 Scrollable interface 来寻找一些想法