我正在尝试为比萨饼定购单设置框架,而orderPanel和buttonsPanel遇到了麻烦。我可以显示一个或另一个,但不能同时显示吗?在我发布的当前代码中,按钮正在显示,但textbox / orderPanel未显示。而且我已经知道了,所以可以显示orderPanel,但是随后它隐藏了按钮,这也不是一件好事。我希望按钮位于最底部,而orderPanel位于其上方;我怎样才能做到这一点?
class PizzaOrderFrame extends JFrame
{
final private JPanel crustPanel, sizePanel, toppingsPanel, orderPanel, buttonsPanel;
final private TitledBorder crustBorder, sizeBorder, toppingsBorder, orderBorder;
final private JButton quitButton, clearButton, orderButton;
final private JTextArea orderTextArea;
final private JRadioButton thin, regular, deepDish;
final private JCheckBox pepperoni, sausage, bacon, extraCheese, olives, mushrooms;
double smallSizeCost = 8.0;
double mediumSizeCost = 12.0;
double largeSizeCost = 16.0;
double superSizeCost = 20.0;
double toppingsCost = 1.0;
double toppingsCount = 0;
double tax = 0.07;
double orderSubTotal = 0;
double orderTotal = 0;
public PizzaOrderFrame()
{
setTitle("Pizza Order Form");
Toolkit kit = Toolkit.getDefaultToolkit();
Dimension screenSize = kit.getScreenSize();
int screenHeight = screenSize.height;
int screenWidth = screenSize.width;
double setScreen = screenWidth * .80;
double setScreen3 = screenHeight * .80;
int setScreen2 = (int) setScreen;
int setScreen4 = (int) setScreen3;
setSize(setScreen2, setScreen4);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
crustPanel = new JPanel();
crustBorder = new TitledBorder("Select your crust");
crustBorder.setTitleJustification(TitledBorder.CENTER);
crustBorder.setTitlePosition(TitledBorder.TOP);
crustPanel.setBorder(crustBorder);
thin = new JRadioButton("Thin");
regular = new JRadioButton("Regular");
deepDish = new JRadioButton("Deep-Dish");
ButtonGroup group = new ButtonGroup();
group.add(thin);
group.add(regular);
group.add(deepDish);
crustPanel.add(thin);
crustPanel.add(regular);
crustPanel.add(deepDish);
add(crustPanel, BorderLayout.WEST);
sizePanel = new JPanel();
sizeBorder = new TitledBorder("Select your size");
sizeBorder.setTitleJustification(TitledBorder.CENTER);
sizeBorder.setTitlePosition(TitledBorder.TOP);
sizePanel.setBorder(sizeBorder);
String[] sizeOptions = new String [] {"Small", "Medium", "Large", "Super" };
JComboBox<String> size = new JComboBox<>(sizeOptions);
String selectedSize = (String) size.getSelectedItem();
sizePanel.add(size);
add(sizePanel, BorderLayout.CENTER);
toppingsPanel = new JPanel();
toppingsBorder = new TitledBorder("Select your toppings");
toppingsBorder.setTitleJustification(TitledBorder.CENTER);
toppingsBorder.setTitlePosition(TitledBorder.TOP);
toppingsPanel.setBorder(toppingsBorder);
pepperoni = new JCheckBox("Pepperoni");
sausage = new JCheckBox("Sausage");
extraCheese = new JCheckBox("Extra Cheese");
mushrooms = new JCheckBox("Mushrooms");
olives = new JCheckBox("Olives");
bacon = new JCheckBox("Bacon");
toppingsPanel.add(pepperoni);
toppingsPanel.add(sausage);
toppingsPanel.add(extraCheese);
toppingsPanel.add(mushrooms);
toppingsPanel.add(olives);
toppingsPanel.add(bacon);
add(toppingsPanel, BorderLayout.EAST);
orderPanel = new JPanel();
orderBorder = new TitledBorder("Your Order");
orderBorder.setTitleJustification(TitledBorder.CENTER);
orderBorder.setTitlePosition(TitledBorder.TOP);
orderPanel.setBorder(orderBorder);
orderTextArea = new JTextArea();
JScrollPane orderSP = new JScrollPane(orderTextArea);
orderSP.setPreferredSize( new Dimension( 300, 100 ) );
orderPanel.add(orderSP);
add(orderPanel, BorderLayout.SOUTH);
buttonsPanel = new JPanel();
quitButton = new JButton("Quit");
clearButton = new JButton("Clear");
orderButton = new JButton("Order");
buttonsPanel.add(quitButton);
buttonsPanel.add(clearButton);
buttonsPanel.add(orderButton);
add(buttonsPanel, BorderLayout.PAGE_END);
}
}
最佳答案
根据JavaDoc for PAGE_END
对于Western,从左到右和从上到下的方向,这等效于SOUTH。
BorderLayout“区域”只能包含一个组件,因此,如果使用同一“区域”多次调用add(),则仅显示最后一个。
获得所需布局的一种方法是创建另一个Panel,为其提供BorderLayout,将orderPanel添加到新Panel的NORTH,将buttonPanel添加到新Panel的SOUTH,然后将新Panel添加到现有pizzaOrderFrame的SOUTH。
关于java - BorderLayout带来的小麻烦,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/43263716/