复制JPanel - （将JPanel的静态图像复制到不同的JPanel） [英] Duplicating a JPanel - (Copy JPanel's static image to different JPanel)
问题描述
我很擅长摇摆，我希望得到一些帮助，因为我坚持完成任务。
I'm pretty new to swing and I would like to receive some help as Im stuck with a task.
当前状态：
我有一个不错的 JFrame 对象（guiFrame）有两个 JPanel 就可以了（tabsPanel和cardPanel）（一个是简单的 JPanel 带按钮，另一个有 CardLayout 由tabsPanel按钮切换）。
Im having a nice JFrame object (guiFrame) which is having two JPanel on it (tabsPanel and cardPanel)(one is a simple JPanel with buttons, the other has CardLayout which is switched by the tabsPanel buttons).
问题：
任务是如果我按按钮 在tabsPanel上我需要将cardPanel作为静态图像发送到另一个窗口（ShowFrame），而在上一个窗口中，程序仍然运行且很好。所以基本上我试图复制/克隆cardPanel。
The task is that if I press the button "Show" on tabsPanel I need to send the cardPanel to a different window (ShowFrame) as a static "image", while on the previous window the program is still running and nice. So basicly Im trying to copy / clone the cardPanel.
我尝试了什么：
-
我试过简单地
I have tried to simply
JPanel jPanelShow = cardPanel;
show.add(jPanelShow);
当然无法正常工作，因为正在复制参考编号，如果我运行程序，则为cardPanel消失。
Of course not working because the reference number is being copied and if I run the program, the cardPanel "disappears".
我试图使用 clone（）
为此它几乎工作，但我得到一些奇怪的 NullPointerException 这不是我的代码造成的。
I have tried to use clone()
For this its almost working but I'm getting some weird NullPointerException which isn't caused by my code.
当前代码（克隆尝试）：
CardPanel.java
CardPanel.java
/**
* This is basicly a JPanel, just with a clone() implemented
*/
package javaapplication5;
import javax.swing.JPanel;
import java.util.Stack;
public class CardPanel extends JPanel implements Cloneable {
public CardPanel() {
super();
}
@Override
public CardPanel clone() throws NullPointerException {
/* Creating return object */
final CardPanel copy;
try {
/* Cloning */
copy = (CardPanel) super.clone();
} catch (CloneNotSupportedException e) {
/* Exception (should not happen though) */
e.printStackTrace();
return null;
}
return copy;
}
}
CardLayoutExample.java
CardLayoutExample.java
package javaapplication5;
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.Border;
public class CardLayoutExample {
JFrame guiFrame;
CardLayout cards;
CardPanel cardPanel;
private int showFrameNotShownYet = 1;
public ShowFrame show = new ShowFrame();
public static void main(String[] args) {
/* Random things for Swing */
EventQueue.invokeLater(new Runnable()
{
@Override
public void run()
{
new CardLayoutExample();
}
});
}
public CardLayoutExample()
{
/* Creating the main JFrame */
guiFrame = new JFrame();
/* Making sure the program exits when the frame closes */
guiFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
guiFrame.setTitle("CardLayout Example");
guiFrame.setSize(400,300);
/* This will center the JFrame in the middle of the screen */
guiFrame.setLocationRelativeTo(null);
guiFrame.setLayout(new BorderLayout());
/* Border for JPanel separation */
Border outline = BorderFactory.createLineBorder(Color.black);
/* Creating JButton1 for tabsPanel */
JButton switchCards1 = new JButton("1");
switchCards1.setActionCommand("1");
switchCards1.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent event)
{
cards.show(cardPanel, "TestContent");
}
});
/* Creating JButton2 for tabsPanel */
JButton switchCards2 = new JButton("2");
switchCards2.setActionCommand("2");
switchCards2.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent event)
{
cards.show(cardPanel, "TestContent1");
}
});
/* Creating JButton3 for tabsPanel */
JButton switchCards3 = new JButton("3");
switchCards3.setActionCommand("3");
switchCards3.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent event)
{
cards.show(cardPanel, "TestContent2");
}
});
JButton switchCards4 = new JButton("Show");
switchCards4.setActionCommand("Show");
switchCards4.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent event)
{
/* If there is no ShowFrame yet */
if(showFrameNotShownYet == 1){
show.add((JPanel)cardPanel.clone());
show.setVisible(true);
showFrameNotShownYet = 0;
}
/* If there is a ShowFrame already */
else {
show.setVisible(false);
showFrameNotShownYet = 1;
guiFrame.repaint();
}
}
});
JButton switchCards5 = new JButton("Refresh");
switchCards5.setActionCommand("Refresh");
switchCards5.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent event)
{
show.setVisible(false);
show.add((JPanel)cardPanel.clone());
show.setVisible(true);
showFrameNotShownYet = 0;
}
});
/* Creating JPanel for buttons */
JPanel tabsPanel = new JPanel();
tabsPanel.setBorder(outline);
tabsPanel.add(switchCards1);
tabsPanel.add(switchCards2);
tabsPanel.add(switchCards3);
tabsPanel.add(switchCards4);
tabsPanel.add(switchCards5);
/* Creating JPanel for CardLayout */
cards = new CardLayout();
cardPanel = new CardPanel();
cardPanel.setLayout(cards);
cards.show(cardPanel, "TestContent");
/* Adding 1st card */
JPanel firstCard = new TestContent();
cardPanel.add(firstCard, "TestContent");
/* Adding 2nd card */
JPanel secondCard = new TestContent1();
cardPanel.add(secondCard, "TestContent1");
/* Adding 3rd card */
JPanel thirdCard = new TestContent2();
cardPanel.add(thirdCard, "TestContent2");
/* Filling up JFrame with stuff */
guiFrame.add(tabsPanel,BorderLayout.NORTH);
guiFrame.add(cardPanel,BorderLayout.CENTER);
guiFrame.setVisible(true);
}
}
TestContent，TestContent1和TestContent2很简单带有SwingGUI生成的随机内容的JPanel，就像ShowFrame是空的JFrame一样。但如果需要，我也会粘贴这些代码。
TestContent, TestContent1 and TestContent2 are simple JPanels with random stuff generated by SwingGUI, just as ShowFrame is empty JFrame. But if needed I will paste in those codes too.
推荐答案
如果您只需要<$ c $的图像 c> cardPanel ，您只需创建一个图像并使用 JLabel 来显示，例如......
If you only need an "image" of the cardPanel, you can simply create an image and use a JLabel to show, for example...
BufferedImage img = new BufferedImage(cardPanel.getWidth(), cardPane.getHeight(), BufferedImage.BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = img.createGraphics();
cardPanel.printAll(g2d);
g2d.dispose();
现在您拥有 cardPanel的副本，您只需使用 JLabel 即可显示它，例如......
Now you have a "copy" of the cardPanel, you can simply use a JLabel to display it, for example...
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.DIPOSE_ON_CLOSE);
frame.add(new JLabel(new ImageIcon(img)));
frame.pack();
frame.setLocationRelativeTo(this);
frame.setVisible(true);
这篇关于复制JPanel - （将JPanel的静态图像复制到不同的JPanel）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
