所以我一直在尝试为牙医创建这个简单的UI,当我在标题下添加顶部菜单时,我注意到“setPreferredSize”没有按预期工作。基本上,我希望菜单水平扩展,所以我使用了GridBagLayout。我还将包含按钮的JPanel的大小设置为我的contentPane的全宽大小。
奇怪的是,如果我调整窗口(JFrame)的大小并使其水平变大,那么JPanel也会调整为首选大小。
JFrame创建时:
这是创建后手动调整大小的JFrame(通过拖动侧面横向变大):
正如你所看到的,一旦我把窗口变大,JPanel的大小就会得到修正。此外,我确保窗口有足够的空间容纳顶部菜单(即使制作出来也比顶部菜单大50像素),但当设置为可见时,它仍然会像第一张图像一样被绘制。
主窗口的代码是:
import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.io.File;
/**
* Created by Matheus on 27/10/2016.
*/
public class WindowTest extends JFrame {
private JPanel contentPane;
private JPanel topMenu;
private JPanel header;
private JPanel dummy;
private JButton home, appointments, healthCare,
patients, contact;
public WindowTest(final int w,final int h) {
super();
// Colours we'll need to paint the UI (RGB format)
final Color lightBlue = new Color(200, 200, 255);
final Color bgBlue = new Color(112, 205, 255);
final Color grey = new Color(128, 128, 128, 40);
final Color white = new Color(255,255,255);
final Color transWhite = new Color(255,255,255, 100);
// Gradient drawing in this area
JPanel contentPane = new JPanel(new GridBagLayout()) {
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D gb = (Graphics2D) g;
gb.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
GradientPaint gp = new GradientPaint(0, 100, bgBlue, 0, h, white);
gb.setPaint(gp);
gb.fillRect(0, 0, w, h);
}
};
contentPane.setPreferredSize(new Dimension(w, h));
// Grid bag contraints here - Initial settings
GridBagConstraints gbc = new GridBagConstraints();
gbc.anchor = GridBagConstraints.FIRST_LINE_START;
// Create the header stuff here.
gbc.gridy = 0;
gbc.gridx = 0;
gbc.weighty = 0;
gbc.weightx = 0;
try{
File imgFile = new File(getClass().getResource("header.jpg").toURI());
Image headerImg = ImageIO.read(imgFile);
header = new ImagePanel(headerImg);
contentPane.add(header, gbc);
}
catch (Exception e){
System.out.println("Failed to load image");
}
// Top menu stuff here
topMenu = new JPanel(new FlowLayout());
topMenu.setBackground(new Color(0,0,0));
topMenu.setPreferredSize(new Dimension(w, 60));
System.out.println(topMenu.getSize());
// Creating menu items
home = new MenuButton(300, 75, "Home", transWhite);
appointments = new MenuButton(300, 75, "Appointments", transWhite);
patients = new MenuButton(300, 75, "Patients", transWhite);
healthCare = new MenuButton(300, 75, "Health Care", transWhite);
contact = new MenuButton(300, 75, "Contact", transWhite);
home = new JButton("Home");
appointments = new JButton("Appointments");
patients = new JButton("Patients");
healthCare = new JButton("Health Care Plan");
contact = new JButton("Contact");
topMenu.add(home);
topMenu.add(appointments);
topMenu.add(patients);
topMenu.add(healthCare);
topMenu.add(contact);
topMenu.revalidate();
gbc.gridy = 1;
gbc.weightx = 1;
gbc.weighty = 0;
contentPane.add(topMenu, gbc);
// Dummy here for the rest of the screen
JPanel dummy = new JPanel();
gbc.gridy = 1;
gbc.weighty = 1;
gbc.weightx = 1;
contentPane.add(dummy, gbc);
// Main window settings
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.add(contentPane);
this.pack();
this.revalidate();
this.setVisible(true);
}
}
我也尝试使用不同的布局管理器,但它们给出了相同的结果。有人能帮我吗?
强制组件填充所有空间的最简单方法是使用BorderLayout。在您的情况下,它应该使用两次。
// Initialize topMenu as before
// Create a panel for image and buttons
JPanel head = new JPanel(new BorderLayout());
// Image will be centered and its height will be preserved
head.add(new JLabel(new ImageIcon(getClass().getResource("header.jpg"))), BorderLayout.PAGE_START);
// Buttons also will be centered and their height will be preserved
head.add(topMenu, BorderLayout.PAGE_END);
// Gradient drawing in this area
JPanel contentPane = new JPanel(new BorderLayout()) {
// paintComponent ...
};
// The height of the head will be preserver,
// but the width will be equal to the window width
contentPane.add(head, BorderLayout.PAGE_START);
// Main component
// Just for the example
final JButton main = new JButton("Test");
main.setOpaque(false);
main.setBackground(Color.MAGENTA);
// Main component will be stretched both vertically and horizontally
contentPane.add(main, BorderLayout.CENTER);