在正确的窗口中创建 GUI

Question

我正在尝试创建一个包含 4 个字段的 GUI。

1. 网址
2. 用户名
3. 密码
4. 声明

在第一次时，这些字段应该是空的。稍后，密码字段旁边的所有字段都应包含上次的信息。

问题：

1. GUI 窗口不应有标准尺寸

   我想要达到的目标：

   • 当窗口打开时，它应该动态调整到笔记本电脑的屏幕尺寸，例如居中，占屏幕的 20%

2. 第四个字段（语句）可能很长，GUI 窗口会自动变得过长。

   我想要达到的目标：

   • 对于第四个字段，应将字符串分解为多行。在将字段拆分为三行而不是继续拆分为第四行后，一个选项可能是滚动条。

到目前为止，我已经找到了一些可以提供帮助的对象。

• JOptionPane
• JPanel

• JTextArea 用于第四个长字段

  对于JTextArea，还有

  • JScrollPane
  • .setLineWrap(true) 换行
  • .setWrapStyleWord(true) 在单词后换行

我的代码示例：

JPanel pane = new JPanel();
// adding GridLayout
pane.setLayout(new GridLayout(4,2));
// fields are filled just as an example
// later they will get substituted by variables
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);
JScrollPane scrollPane = new JScrollPane(statement);
pane.add(scrollPane);
// add infos to pane
pane.add(new JLabel ("Enter url: "));
pane.add(url);
pane.add(new JLabel ("Enter username: "));
pane.add(username);
pane.add(new JLabel ("Enter password: "));
pane.add(new JPasswordField());
pane.add(new JLabel ("Enter statement: "));
pane.add(statement);
//write it to a OK_CANCEL JOptionPane
int option = JOptionPane.showConfirmDialog(null,pane, "Fill all the fields",JOptionPane.OK_CANCEL_OPTION,JOptionPane.INFORMATION_MESSAGE);

Answer 1

您可以使用setRows() 设置JTextArea 的高度（可见行数）。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：