我这里有一个简单的订购系统，要求用户输入收银员名称，客户名称和密码。用户完成该过程后，将显示包含不同餐点的组合框。
我想要发生的是，一旦我点击了一顿饭，它应该显示我选择的一餐的名称，并且应该执行我在actionlistener中声明的动作。
程序编译得很好，但我想要发生的逻辑不起作用，我正在尽力解决这个问题，但我想我自己不能这样做请帮助我谢谢！
import java.util.Scanner;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class SubokUlit {
private JComboBox combo;
private String a = "";
private static int answer;
private static int total = 0;
private static int total1 = 0;
private static int wew = 0;
private static String order1 = "";
private static String order2 = "";
private static Scanner inp = new Scanner(System.in);
public SubokUlit(){
String mgaPagkainTo[] = {"PM1 (Paa/ Spicy Paa with Thigh part)","PM2 (Pecho)"};
JFrame frame = new JFrame("Mang Inasal Ordering System");
JPanel panel = new JPanel();
combo = new JComboBox(mgaPagkainTo);
combo.setBackground(Color.gray);
combo.setForeground(Color.red);
panel.add(combo);
frame.add(panel);
combo.addActionListener(new ActionListener(){ // The logic in here does not work
public void actionPerformed(ActionEvent e){
String str = (String)combo.getSelectedItem();
a = str;
if(a.equals("PM1 (Paa/ Spicy Paa with Thigh part)")){ // If I select PM1 in the combo box it should do the following. But it doesn't work
System.out.print ("\n\n\n\t\tYou have chosen Paborito Meal 1.\n");
System.out.print ("\t\t\tPlease enter the quantity: ");
int quantity1 = inp.nextInt();
total = quantity1 * 99;
order1 = quantity1 + " " + "PM1 " + " " + total +"\n";
}
else if(a.equals("PM2 (Pecho)")){ // The same thing should alaso happen here in PM2
System.out.print ("\n\n\n\t\tYou have chosen Paborito Meal 2.\n");
System.out.print ("\t\t\tPlease enter the quantity: ");
int quantity2 = inp.nextInt();
total1 = quantity2 * 99;
order2 = quantity2 + " " + "PM2 " + " " + total1 +"\n";
}
}
});
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300,100);
frame.setVisible(true);
}
public static void main(String[]args) {
Scanner inp = new Scanner(System.in);
String userNamePoe = "";
String customerNamePoe = "";
String sanKaKain = "";
boolean ulitinMoPows = true;
boolean tryAgain = true;
System.out.print("\nInput Customer Name: ");
String customerName = inp.nextLine();
customerNamePoe = customerName;
System.out.print("\nInput Cashier Name: ");
String user = inp.nextLine();
userNamePoe = user;
do{
System.out.print("\nInput either Dine In or Take Out: ");
String dInDOut = inp.nextLine();
sanKaKain = dInDOut;
if (sanKaKain.equals("Dine In") || sanKaKain.equals("Take Out")){
System.out.print("");
ulitinMoPows = false;
}
else{
JOptionPane.showMessageDialog(null, "Try again! Please input Dine In or Take Out only!","Error", JOptionPane.ERROR_MESSAGE);
ulitinMoPows = true;
System.out.print ("\f");
}
}while(ulitinMoPows);
do{
System.out.print("\nInput password: ");
String pass = inp.nextLine();
if(pass.equals("admin")){
System.out.print("");
tryAgain = false;
}
if(!pass.equals("admin")){
JOptionPane.showMessageDialog(null, "Try again! Invalid password!","Error Logging-In", JOptionPane.ERROR_MESSAGE);
tryAgain = true;
System.out.print ("\f");
}
}while(tryAgain);
System.out.print("\n\n\t\tCashier: " +userNamePoe);
System.out.print(" "+sanKaKain);
System.out.print("\n\t\tCustomer Name: " +customerNamePoe);
SubokUlit j = new SubokUlit(); //Supposedly, once the selecting of meal is done, it should now go to the next part wherein the total bill will display and asks the user how much is his cash.
int lahatNgOrderMo = total + total1;
double multiplierVat = 0.12;
double vatCollected = lahatNgOrderMo * multiplierVat;
System.out.print("\n\n\tYour total bill is: "+lahatNgOrderMo); // Displays the bill
System.out.print("\n\tCash Tendered: "); // Asks the user how much is his cash
double cashTendered = inp.nextInt();
double sukliMo = cashTendered - lahatNgOrderMo;
System.out.print("\n\n\t\t MANG INASAL");
System.out.print("\n\t\t BLUMENTRITT BRANCH");
System.out.print("\n\t\t #1631-1633 BLUMENTRITT ST.,");
System.out.print("\n\t\t STA CRUZ. MANILA 0000");
System.out.print("\n\t\t (932) 885-5844\n");
System.out.print("\n\t\t Operated by: R L YU");
System.out.print("\n\t\t TIN 202-161-017-000 VAT");
System.out.print("\n\t\t ACC. NO.: 050-204079836-000019");
System.out.print("\n\t\t Tel. #: (02)493-6801");
System.out.print("\n\n\t\tCashier: " +userNamePoe);
System.out.print("\t\t STATION: 2");
System.out.print("\n\t\t---------------------------------------------");
System.out.print("\n\t\tO.R #: 84486");
System.out.print(" "+sanKaKain);
System.out.print("\t\t\n Customer Name: " +customerNamePoe);
System.out.print(" 24");
System.out.print("\n\t\t---------------------------------------------");
System.out.print("\n\t\t >>SETTLED<<\n\n");
System.out.print(""+order1);
System.out.print(""+order2);
System.out.print("\n\n\t\tSUB TOTAL: "+lahatNgOrderMo);
System.out.print("\n\t\tDELIVERY VAT: 0.00");
System.out.print("\n\t\t ======");
System.out.print("\n\t\tAMOUNT DUE: "+lahatNgOrderMo);
System.out.print("\n\n\t\tVAT 12% COLLECTED "+vatCollected);
System.out.print("\n\n\t\tCASH Tendered: "+cashTendered);
System.out.print("\n\t\t ======");
System.out.print("\n\t\tCHANGE: "+sukliMo);
System.out.print("\n\t\t >>Ticket #: 62<<");
System.out.print("\n\t\t Created: ");
System.out.print("\n\t\t SETTLED: ");
System.out.print("\n\n\t\t*********************************************");
System.out.print("\n\t\tTHIS SERVES AS AN OFFICIAL RECEIPT.");
System.out.print("\n\n\t\tFor Feedback: TEXT MIO467(Comments/ Suggest");
System.out.print("\n\t\tions) and SEND to 0917-5941111 or CALL US");
System.out.print("\n\t\tat 0917-5596258");
System.out.print("\n\t\tEmail: feedback@manginasal.com");
System.out.print("\n\n\t\t THANK YOU FOR DINING WITH US!");
System.out.print("\n\n\t\t*********************************************");
System.out.print("\n\t\tS/N: 120416ASL03/1105-6105-9230");
System.out.print("\n\t\tDT S/N: 41-L6971 (P0S1)");
System.out.print("\n\t\tPERMIT NO: 0412-031-125295-000");
System.out.print("\n\t\tMIN: 120276752");
}
}
答案 0 :(得分：1)
您必须确保将eventlistener附加到JComboBox，以便应用程序知道在发生某些事情时该怎么做。
在这种情况下，您要附加ItemListener()。
您可以使用以下内容：
combo.addItemListener(new ItemListener() {
@Override
public void itemStateChanged(ItemEvent e) {
System.out.println("Meal chosen: " + combo.getSelectedItem().toString());
String optionalParameter = combo.getSelectedItem().toString();
DoMethodWhatYouNeedToDoWhenYouSelectedSomething(optionalParameter);
}
});
编辑：你的代码应该是这样的：
combo.addActionListener(new ItemListener(){
@Override
public void itemStateChanged(ItemEvent e){
String str = (String)combo.getSelectedItem();
a = str;
if(a.equals("PM1 (Paa/ Spicy Paa with Thigh part)")){
System.out.print ("\n\n\n\t\tYou have chosen Paborito Meal 1.\n");
System.out.print ("\t\t\tPlease enter the quantity: ");
int quantity1 = inp.nextInt();
total = quantity1 * 99;
order1 = quantity1 + " " + "PM1 " + " " + total +"\n";
}
else if(a.equals("PM2 (Pecho)")){
System.out.print ("\n\n\n\t\tYou have chosen Paborito Meal 2.\n");
System.out.print ("\t\t\tPlease enter the quantity: ");
int quantity2 = inp.nextInt();
total1 = quantity2 * 99;
order2 = quantity2 + " " + "PM2 " + " " + total1 +"\n";
}
}
});