使用 GridBagLayout 时组件无法正确显示
The component doesn't display correctly with GridBagLayout
我正在学习 java 挥杆,这让我很困惑。退出按钮不显示。但是,如果我将 textArea
的代码部分移到按钮的两部分之后,它将正确显示。那为什么?
package exercise1;
import javax.swing.*;
import java.awt.*;
public class ChatClient {
private JTextArea textArea;
private JTextField textField;
private JButton btnSend;
private JButton btnQuit;
private JFrame frame;
private JPanel panel;
private JScrollPane scrollPane;
private void launchFrame() {
panel = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
textArea = new JTextArea(10, 50);
scrollPane = new JScrollPane(textArea);
c.gridx = 0;
c.gridy = 0;
c.gridheight = 3;
panel.add(scrollPane, c);
btnSend = new JButton("Send");
c.gridx = 1;
c.gridy = 0;
c.anchor = GridBagConstraints.NORTH;
panel.add(btnSend, c);
btnQuit = new JButton("Quit");
c.gridx = 1;
c.gridy = 1;
c.anchor = GridBagConstraints.NORTH;
panel.add(btnQuit, c);
}
protected ChatClient() {
frame = new JFrame("Chat Room");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
launchFrame();
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
ChatClient client = new ChatClient();
}
}
简单:您在添加 JScrollPane 后忘记重置 c.gridheight = 1;
。如果不这样做,发送按钮将覆盖退出按钮。
private void launchFrame() {
panel = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL; // ** This is also worthwhile **
textArea = new JTextArea(10, 50);
scrollPane = new JScrollPane(textArea);
c.gridx = 0;
c.gridy = 0;
c.gridheight = 3;
panel.add(scrollPane, c);
btnSend = new JButton("Send");
c.gridx = 1;
c.gridy = 0;
c.gridheight = 1; // ********* ADD THIS *********
c.anchor = GridBagConstraints.NORTH;
panel.add(btnSend, c);
btnQuit = new JButton("Quit");
c.gridx = 1;
c.gridy = 1;
c.anchor = GridBagConstraints.NORTH;
panel.add(btnQuit, c);
}
我正在学习 java 挥杆,这让我很困惑。退出按钮不显示。但是,如果我将 textArea
的代码部分移到按钮的两部分之后,它将正确显示。那为什么?
package exercise1;
import javax.swing.*;
import java.awt.*;
public class ChatClient {
private JTextArea textArea;
private JTextField textField;
private JButton btnSend;
private JButton btnQuit;
private JFrame frame;
private JPanel panel;
private JScrollPane scrollPane;
private void launchFrame() {
panel = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
textArea = new JTextArea(10, 50);
scrollPane = new JScrollPane(textArea);
c.gridx = 0;
c.gridy = 0;
c.gridheight = 3;
panel.add(scrollPane, c);
btnSend = new JButton("Send");
c.gridx = 1;
c.gridy = 0;
c.anchor = GridBagConstraints.NORTH;
panel.add(btnSend, c);
btnQuit = new JButton("Quit");
c.gridx = 1;
c.gridy = 1;
c.anchor = GridBagConstraints.NORTH;
panel.add(btnQuit, c);
}
protected ChatClient() {
frame = new JFrame("Chat Room");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
launchFrame();
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
ChatClient client = new ChatClient();
}
}
简单:您在添加 JScrollPane 后忘记重置 c.gridheight = 1;
。如果不这样做,发送按钮将覆盖退出按钮。
private void launchFrame() {
panel = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL; // ** This is also worthwhile **
textArea = new JTextArea(10, 50);
scrollPane = new JScrollPane(textArea);
c.gridx = 0;
c.gridy = 0;
c.gridheight = 3;
panel.add(scrollPane, c);
btnSend = new JButton("Send");
c.gridx = 1;
c.gridy = 0;
c.gridheight = 1; // ********* ADD THIS *********
c.anchor = GridBagConstraints.NORTH;
panel.add(btnSend, c);
btnQuit = new JButton("Quit");
c.gridx = 1;
c.gridy = 1;
c.anchor = GridBagConstraints.NORTH;
panel.add(btnQuit, c);
}