处理多个操作侦听器

Question

我无法获得小计，税款和总计以显示我的程序。我知道我需要，我只是有与实施的不同组合框多的听众以及复选框

import java.awt.BorderLayout; 
import java.awt.FlowLayout; 
import java.awt.GridLayout; 
import java.text.DecimalFormat; 
import javax.swing.*; 
import javax.swing.event.*; 
import java.awt.*; 

public class SB2_Designer extends JFrame { 
    private final int WINDOW_WIDTH = 400; // Window width 
    private final int WINDOW_HEIGHT = 500; // Window height 

    //Deck 
    private JLabel Dlabel; 
    private JComboBox Dbox; 
    //Prices for boards 
    public final double _Master = 60.00; 
    public final double _Dictat = 45.00; 
    public final double _Street = 50.00; 

    //Trucks 
    private JLabel Trlabel; 
    private JComboBox Trbox; 
    // Prices for Tucks 
    public final double _sevenSeven = 35.00; 
    public final double _eight = 40.00; 
    public final double _eightFive = 45.00; 

    //Wheels 
    private JLabel Wlabel; 
    private JComboBox Wbox; 
    // Prices for Wheels 
    public final double _fiveOne = 20.00; 
    public final double _fiveFive = 22.00; 
    public final double _fiveEight = 24.00; 
    public final double _sixOne = 24.00; 

    //Arrays for ComboBox 
    private String[] Decks = {"The Master Thrasher: $60", 
      "The Dictator: $45", "The Street King: $50"}; 
    private String[] Trucks = {"7.75 inch axle: $35", 
      "8 inch axle: $40", "8.5 inch axle: $45"}; 
    private String[] Wheels = {"51 mm: $20", 
      "55 mm: $22", "58 mm: $24", 
      "61 mm: $28"}; 

    // accessories check box and label 
    private JLabel Atitle; 
    private JCheckBox GripBox; 
    private JCheckBox BearBox; 
    private JCheckBox RiseBox; 
    private JCheckBox BoltBox; 
    public final double _Grip = 10.00; 
    public final double _Bear = 30.00; 
    public final double _Rise = 2.00; 
    public final double _Bolt = 3.00; 


    // Subtotal and textfield 
    private JLabel StLabel; 
    private JTextField Stfield; 
    //Tax and text field 
    private JLabel TaxLabel; 
    private JTextField Taxfield; 
    // Total and text field 
    private JLabel TotLabel; 
    private JTextField Totfield; 

    // Panels 
    private JPanel Dpanel; // Deck panel 
    private JPanel Trpanel; // Trucks panel 
    private JPanel Wpanel; // Wheel panel 
    private JPanel ATitleP;  // Accessories Title 
    private JPanel Apanel; //accessories panel 
    private JPanel Stpanel; // Subtotal panel 
    private JPanel Taxpanel; // Tax panel 
    private JPanel Totpanel; // Total panel 


    public SB2_Designer() { 
     // Set the title bar text. 
     setTitle("Skateboard Designer"); 

     // Set the size of the window. 
     setSize(WINDOW_WIDTH, WINDOW_HEIGHT); 

     // Specify an action for the close button. 
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

     // Add a GridLayout manager to the content pane. 
     setLayout(new GridLayout(9, 1)); 

     // Build the panels. 
     buildDpanel(); 
     buildTrpanel(); 
     buildWpanel(); 
     buildATitle(); 
     buildApanel(); 
     buildStpanel(); 
     buildTaxpanel(); 
     buildTotpanel(); 


     add(Dpanel); 
     add(Trpanel); 
     add(Wpanel); 
     add(ATitleP); 
     add(Apanel); 
     add(Stpanel); 
     add(Taxpanel); 
     add(Totpanel); 

     pack(); 
     setVisible(true); 
    } 


    // Deck panel 
    private void buildDpanel() { 

     Dpanel = new JPanel(); 
     Dlabel = new JLabel("Decks"); 
     Dpanel.add(Dlabel); 
     Dbox = new JComboBox(Decks); 
     Dpanel.add(Dbox); 
    } 

    public double getDeckPrice() { 
     double deckPrice = 0.0; 

     if (Dbox.getSelectedItem().equals("The Master Thrasher: $60")) 
      deckPrice = _Master; 

     else if (Dbox.getSelectedItem().equals("The Dictator: $45")) 
      deckPrice = _Dictat; 

     else if (Dbox.getSelectedItem().equals("The Street King: $50")) 
      deckPrice = _Street; 

     return deckPrice; 
    } 


    // Truck panel 
    private void buildTrpanel() { 

     Trpanel = new JPanel(); 
     Trlabel = new JLabel("Trucks"); 
     Trbox = new JComboBox(Trucks); 
     Trpanel.add(Trlabel); 
     Trpanel.add(Trbox); 
    } 

    public double getTruckPrice() { 
     double TruckPrice = 0.0; 

     if (Trbox.getSelectedItem().equals("7.75 inch axle: $35")) 
      TruckPrice = _sevenSeven; 

     else if (Trbox.getSelectedItem().equals("8 inch axle: $40")) 
      TruckPrice = _eight; 

     else if (Trbox.getSelectedItem().equals("8.5 inch axle: $45")) 
      TruckPrice = _eightFive; 

     return TruckPrice; 
    } 

    // Wheel panel 
    private void buildWpanel() { 

     Wpanel = new JPanel(); 
     Wlabel = new JLabel("Wheels"); 
     Wbox = new JComboBox(Wheels); 
     Wpanel.add(Wlabel); 

     Wpanel.add(Wbox); 
    } 

    public double getWheelPrice() { 
     double WheelPrice = 0.0; 

     if (Wbox.getSelectedItem().equals("51 mm: $20")) 
      WheelPrice = _fiveOne; 

     else if (Wbox.getSelectedItem().equals("55 mm: $22")) 
      WheelPrice = _fiveFive; 

     else if (Wbox.getSelectedItem().equals("58 mm: $24")) 
      WheelPrice = _fiveEight; 

     else if (Wbox.getSelectedItem().equals("61 mm: $28")) 
      WheelPrice = _sixOne; 

     return WheelPrice; 
    } 


    private void buildATitle() { 
     // Create a label. 
     Atitle = new JLabel("Select from the differect accessories below"); 
     ATitleP = new JPanel(); 
     ATitleP.add(Atitle); 

    } 

    private void buildApanel() { 

     // Create the check boxes. 
     GripBox = new JCheckBox("Grip Tape: $10"); 
     BearBox = new JCheckBox("Bearings: $30"); 
     RiseBox = new JCheckBox("Riser Pads: $2"); 
     BoltBox = new JCheckBox("Nuts & Bolts Kit: $3"); 

     // adds check box panel 
     Apanel = new JPanel(); 
     Apanel.add(GripBox); 
     Apanel.add(BearBox); 
     Apanel.add(RiseBox); 
     Apanel.add(BoltBox); 
    } 

    public double getAccprice() { 
     double Accprice = 0; 

     if (GripBox.isSelected()) 
      Accprice += _Grip; 
     if (BearBox.isSelected()) 
      Accprice += _Bear; 
     if (RiseBox.isSelected()) 
      Accprice += _Rise; 
     if (BoltBox.isSelected()) 
      Accprice += _Bolt; 

     return Accprice; 
    } 

    private void buildStpanel() { 
     StLabel = new JLabel("Sub-Total:"); 
     Stfield = new JTextField(10); 
     Stfield.setEditable(false); 
     Stfield.setText("0.00"); 

     Stpanel = new JPanel(); 
     Stpanel.add(StLabel); 
     Stpanel.add(Stfield); 
    } 

    private void buildTaxpanel() { 
     TaxLabel = new JLabel("Tax:"); 
     Taxfield = new JTextField(10); 
     Taxfield.setEditable(false); 
     Taxfield.setText("0.00"); 

     Taxpanel = new JPanel(); 
     Taxpanel.add(TaxLabel); 
     Taxpanel.add(Taxfield); 
    } 

    private void buildTotpanel() { 
     TotLabel = new JLabel("Total:"); 
     Totfield = new JTextField(10); 
     Totfield.setEditable(false); 
     Totfield.setText("0.00"); 

     Totpanel = new JPanel(); 
     Totpanel.add(TotLabel); 
     Totpanel.add(Totfield); 
    } 


    public void calc() { 
     double subtotal; 
     double salestax = 0.06; 
     double total; 
     double tax; 


     DecimalFormat dollar = new DecimalFormat("#,##0.00"); 

     subtotal = getDeckPrice() + getTruckPrice() + getWheelPrice(); 

     //get tax rate 
     tax = subtotal * salestax; 

     //calc tax amount 
     total = subtotal + tax; 

     //parse and format tax amount 
     //set tax text field with tax amount 
     Stfield.setText(dollar.format(subtotal)); 
     Taxfield.setText(dollar.format(tax)); 
     Totfield.setText(dollar.format(total)); 

    } 


    public static void main(String[] args) { 
     new SB2_Designer(); 
    } 
} 

Answer 1

我自己问题的动作侦听器，我会从所有这些组件删除监听器，而是添加一个到的JButton你的图形用户界面，一个“全部”JButton，一个按钮，它的责任是让用户告诉应用程序他已经完成了GUI中的所有信息输入，现在需要计算他的账单。一个监听器会被添加到那个JButton中，并且当它被按下时，它将会查询你的JComboBoxes，你的JRadioButtons和你的JCheckBoxes的状态，并且总结一切。

Answer 2

那么你已经拥有的方法称为计算（），所有你需要做的就是添加一个ActionListener您希望加入到每个组件，并调用该方法：

oneOfYourComboBoxes.addActionListener(new ActionListener(){ 

    @Override 
    public void onActionPerformed(ActionEvent evt){ 

     //just call calc 
     calc(); 

    } 

}); 

Answer 3

的三个组合框可以使用一个调用calc方法的ActionListener，四个复选框可以以类似的方式使用ItemListener。您可以将下面的代码添加到SB2_Designer构造函数（使用Java 8语法两个听众）：

add(Dpanel); 
add(Trpanel); 
add(Wpanel); 
add(ATitleP); 
add(Apanel); 
add(Stpanel); 
add(Taxpanel); 
add(Totpanel); 

// New code starts here. 
calc(); 

ActionListener actionListener = actionEvent -> calc(); 
Dbox.addActionListener(actionListener); 
Trbox.addActionListener(actionListener); 
Wbox.addActionListener(actionListener); 

ItemListener itemListener = itemEvent -> calc(); 
GripBox.addItemListener(itemListener); 
BearBox.addItemListener(itemListener); 
RiseBox.addItemListener(itemListener); 
BoltBox.addItemListener(itemListener); 
// New code ends here. 

pack(); 
setVisible(true); 

对于Java 7之前，您可以创建两个监听器是这样的：

​​3210

在calc方法中，附件的价格尚未考虑在内。如果你更换下面的线，它应该工作：

//subtotal = getDeckPrice()+ getTruckPrice() + getWheelPrice(); 
subtotal = getDeckPrice()+ getTruckPrice() + getWheelPrice() + getAccprice();