Java CardLayout主菜单问题 [英] Java CardLayout Main Menu Problem
问题描述
好的，所以即时通讯工作在java中称为8位嵌合体。我现在在主菜单上工作但是当我使用卡片布局时，窗口由于某种原因不会打开。这是一些代码。
Ok so im working on this game in java called 8 bit chimera. Im working on the main menu right now but when im using the card layout the window wont open for some reason. Here is some code.
import javax.swing.*;
import java.awt.*;
public class MainScreen extends JFrame{
String Title = "MainMenu";
MainMenuComp MMC = new MainMenuComp();
BreedingGround BGR = new BreedingGround();
public MainScreen() {
setTitle("8-bit Chimera "+Title);
setSize(800,600);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
add(MMC);
add(BGR);
}
public static void main(String[] args){
new MainScreen();
}
}
这是主窗口
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class MainMenuComp extends JPanel implements ActionListener{
BreedingGround BGR = new BreedingGround();
ImageData ID = new ImageData();
Image TitleBg;
Image Title;
CardLayout CL;
JButton Play;
public MainMenuComp() {
setLayout(new GridBagLayout());
GridBagConstraints GBC = new GridBagConstraints();
ImageIcon TitleData = new ImageIcon(ID.TitleSource);
ImageIcon TitleBackGroundData = new ImageIcon(ID.TitleBackGroundSource);
ImageIcon PlayData = new ImageIcon(ID.PlaySource);
TitleBg = TitleBackGroundData.getImage();
Title = TitleData.getImage();
Play = new JButton();
Play.setIcon(PlayData);
add(Play,GBC);
add(BGR,"Breed");
}
public void actionPerformed(ActionEvent AE){
if(AE.getSource() == Play){
CL.show(this, "Breed");
}
}
public void paintComponent(Graphics g){
g.drawImage(TitleBg,0,0,800,600,this);
g.drawImage(Title,250,80,280,140,this);
}
}
这是卡片布局
import javax.swing.*;
import java.awt.*;
public class BreedingGround extends JPanel{
ImageData ID = new ImageData();
Image Swamp;
CardLayout CL;
public BreedingGround(){
setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
ImageIcon SwampData = new ImageIcon(ID.SwampSource);
Swamp = SwampData.getImage();
}
public void paintComponent(Graphics g){
g.drawImage(Swamp,0,0,800,600,this);
}
}
这就是我想要的CardLayout打开。问题是，当我尝试运行它时窗口不会运行，这会在编译器中显示。
and that was what i wanted the CardLayout to open. The problem is that when i try to run it the window wont run and this keeps showing in the compiler.
------------- -------配置：8位嵌合体 - JDK版本1.6.0_26 - --------------------
--------------------Configuration: 8-bit Chimera - JDK version 1.6.0_26 - --------------------
Exception in thread "main" java.lang.IllegalArgumentException: cannot add to layout: constraints must be a GridBagConstraint
at java.awt.GridBagLayout.addLayoutComponent(GridBagLayout.java:685)
at java.awt.Container.addImpl(Container.java:1074)
at java.awt.Container.add(Container.java:927)
at MainMenuComp.<init>(MainMenuComp.java:26)
at MainScreen.<init>(MainScreen.java:7)
at MainScreen.main(MainScreen.java:23)
流程已完成。
所有我真的想知道的是这是什么是的。
All i really want to know is what this is saying.
推荐答案
我没看到你把容器的布局设置为CardLayout，如果你不喜欢没有设置布局到此，你不能神奇地使用它。如果您尚未完成 CardLayout教程，请考虑这样做就完全解释了。
I don't see where you ever set the layout of a container to be CardLayout, and if you don't set the layout to this, you can't magically use it. If you haven't yet gone through the CardLayout tutorial, consider doing so as it's all explained there.
编辑1
来自Alexander Kim的评论：
Edit 1
Comment from Alexander Kim:
当我添加cardbagLayout时它不会加载图像并且按钮大小填满整个屏幕。我还带走了网格
when i added the cardbagLayout it wont load the image and the button size filled the whole screen. I also took away the grids
您需要嵌套JPanel以嵌套布局。使用单个JPanel作为CardLayout容器，其单个功能是显示其他JPanel（卡）。这些其他JPanel将使用正确显示它们所持有的组件所需的任何布局，例如JButton或网格（无论它们是什么）。甚至这些JPanels也可能拥有其他使用其他布局的JPanel。
You need to nest your JPanels in order to nest layouts. Use a single JPanel as the CardLayout container whose single function it is is to display other JPanels (the "cards"). These other JPanels will use whatever layouts that are necessary to properly display the components that they hold such as your JButton or "grids" (whatever they are). And even these JPanels may hold other JPanels that use other layouts.
再次，请阅读布局教程，因为它在那里都很好。你不会后悔这样做。
Again, please read the layout tutorials as it's all described well there. You will not regret doing this.
编辑2
这是一个使用CardLayout的非常简单的例子。 CardLayout使用JPanel（称为cardContainer）显示的组件根据组合框中选择的项目而改变。
Edit 2
Here's a very simple example that uses a CardLayout. The component displayed by the CardLayout using JPanel (called the cardContainer) is changed depending on which item is selected in a combobox.
这是CardLayout和使用它的JPanel：
Here's the CardLayout and the JPanel that uses it:
私人CardLayout cardLayout = new CardLayout（）;
private CardLayout cardLayout = new CardLayout();
// *** JPanel to hold the "cards" and to use the CardLayout:
private JPanel cardContainer = new JPanel(cardLayout);
以下是我使用JPanel向cardlayout添加组件的方法：
And here's how I add a component to the cardlayout-using JPanel:
JPanel redPanel = new JPanel();
//...
String red = "Red Panel";
cardContainer.add(redPanel, red); // add the JPanel to the container with the String
我还将字符串添加到JComboBox中，所以我如果用户在同一个JComboBox中选择项目Red，可以稍后使用此组合框告诉CardLayout显示此JPanel（redPanel）：
I also add the String to a JComboBox so I can use this combo box later to tell the CardLayout to display this JPanel (redPanel) if the user selects the item "Red" in this same JComboBox:
cardCombo.addItem(red); // also add the String to the JComboBox
这是JComboBox中允许我更改项目的ActionListener使用JPanel在cardlayout中显示：
Here's the ActionListener in the JComboBox that lets me change the item displayed in the cardlayout using JPanel:
cardCombo.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String item = cardCombo.getSelectedItem().toString();
// *** if combo box changes it tells the CardLayout to
// *** swap views based on the item selected in the combo box:
cardLayout.show(cardContainer, item);
}
});
这是整个shebang：
And here's the whole shebang:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class SimpleCardLayoutDemo {
private CardLayout cardLayout = new CardLayout();
// *** JPanel to hold the "cards" and to use the CardLayout:
private JPanel cardContainer = new JPanel(cardLayout);
private JComboBox cardCombo = new JComboBox();
private JPanel comboPanel = new JPanel();;
public SimpleCardLayoutDemo() {
JPanel greenPanel = new JPanel(new BorderLayout());
greenPanel.setBackground(Color.green);
greenPanel.add(new JScrollPane(new JTextArea(10, 25)), BorderLayout.CENTER);
greenPanel.setBorder(BorderFactory.createEmptyBorder(15, 15, 15, 15));
greenPanel.add(new JButton("Bottom Button"), BorderLayout.PAGE_END);
String green = "Green Panel";
cardContainer.add(greenPanel, green);
cardCombo.addItem(green);
JPanel redPanel = new JPanel();
redPanel.setBackground(Color.red);
redPanel.add(new JButton("Foo"));
redPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
String red = "Red Panel";
cardContainer.add(redPanel, red);
cardCombo.addItem(red);
JPanel bluePanel = new JPanel();
bluePanel.setBackground(Color.blue);
JLabel label = new JLabel("Blue Panel", SwingConstants.CENTER);
label.setForeground(Color.white);
label.setFont(label.getFont().deriveFont(Font.BOLD, 32f));
bluePanel.add(label);
String blue = "Blue Panel";
cardContainer.add(bluePanel, blue);
cardCombo.addItem(blue);
comboPanel.add(cardCombo);
cardCombo.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String item = cardCombo.getSelectedItem().toString();
// *** if combo box changes it tells the CardLayout to
// *** swap views based on the item selected in the combo box:
cardLayout.show(cardContainer, item);
}
});
}
public JPanel getCardContainerPanel() {
return cardContainer;
}
public Component getComboPanel() {
return comboPanel ;
}
private static void createAndShowUI() {
SimpleCardLayoutDemo simplecardDemo = new SimpleCardLayoutDemo();
JFrame frame = new JFrame("Simple CardLayout Demo");
frame.getContentPane().add(simplecardDemo.getCardContainerPanel(), BorderLayout.CENTER);
frame.getContentPane().add(simplecardDemo.getComboPanel(), BorderLayout.PAGE_END);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
// to run Swing in a thread-safe way
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
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