Question

我之前没有在java中使用过很多comboBox，而且我在显示文本文件时遇到了一些麻烦。我相信我正确加载文件，但似乎我发现很难在代码中实现它。我在文本文件中有多个电影名称。当在组合框中选择不同的电影时，它会更改价格，评级等......

使用初始化数组后，我正确地完成了这项工作。

文本文件的示例[Taken，PG-13,8：00Am，7,50

import java.awt.event.*;
import java.io.File;
import java.util.ArrayList;
import java.util.Scanner;
import java.util.*;

import javax.swing.*;

public class MovieSelection extends JFrame {
private JPanel ratingPanel;
private JPanel panel;
private JLabel priceLabel;
private JLabel label;
private JButton addCart;    
private JButton backButton;
private JButton resetButton;
private JTextField selectedRatingPanel;
private JTextField amountTextField;
private JComboBox movieBox;

private ArrayList<String> movieName;
private ArrayList<String> movieRating;
private ArrayList<String> movieTime;
private ArrayList<String> moviePrice;

public MovieSelection() {
    super("Please select your movie");
    setSize(575,400);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLocationRelativeTo(null);
    buildMoviePanel();
    buildRatingPanel();
    add(panel);
    setVisible(true);
    movieName = new ArrayList<>();
    movieRating = new ArrayList<>();
    movieTime = new ArrayList<>();
    moviePrice = new ArrayList<>();



}
private void readMovies() {
    Scanner input=null;

try{

     input  = new Scanner(new File("TheMovies.txt"));

     while(input.hasNext()){

        String str = input.nextLine();
        StringTokenizer strT = new StringTokenizer(str, ",");

        movieName.add(strT.nextToken());
        movieRating.add(strT.nextToken());
        moviePrice.add(strT.nextToken());
        movieTime.add(strT.nextToken());


    }

}

catch(Exception element){
    input.close();
    JOptionPane.showMessageDialog(null, "Error");
}


}
private void buildMoviePanel() {

    panel = new JPanel();
    priceLabel = new JLabel("Cost:");
    backButton = new JButton("Back");
    resetButton = new JButton("Rest");

    backButton.addActionListener(new BackButton());
    resetButton.addActionListener(new ResetButton());

    addCart = new JButton("Add to cart");

    JTextField totalTextField = new JTextField(10);
    JTextField priceTextField = new JTextField(5);
    JTextField amountTextField =  new JTextField(4);
    priceTextField.setEditable(false);
    priceTextField.setText(moviePrice);

    totalTextField.setEditable(false);


    JComboBox movieLists = new JComboBox(movieName);



    movieLists.setSelectedIndex(0);
    movieLists.addActionListener(new MovieLists());

    panel.add(movieLists).setBounds(20,52,80,40);
    panel.add(priceLabel).setBounds(375,0,80,40);

    panel.add(priceTextField).setBounds(375,52,75,40);
    panel.add(backButton).setBounds(20,310,80,40);
    panel.add(addCart).setBounds(380,310,100,40);
    panel.add(resetButton).setBounds(200, 310, 80, 40);
    panel.add(amountTextField);

    panel.setLayout(null);
}//buildPanel


private void buildRatingPanel(){
    ratingPanel = new JPanel();
    label = new JLabel("Rating:");
    selectedRatingPanel =  new JTextField(9);
    selectedRatingPanel.setEditable(false);
    selectedRatingPanel.setText("R");

    panel.add(label).setBounds(245, 0, 100,40);

    panel.add(selectedRatingPanel).setBounds(245,52,100,40);
}

private class MovieLists implements ActionListener {
    public void actionPerformed(ActionEvent e) {

        JComboBox cb = (JComboBox) e.getSource();
        String theMovie = (String) cb.getSelectedItem();

        System.out.println(cb.getSelectedIndex());


    }

}
    private class BackButton implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            // return back to home page
            if (e.getSource() == backButton)
                new SelectUserWindow();
                setVisible(false);

        }
    }

    private class ResetButton implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            // return back to home page
            if (e.getSource() == resetButton);


        }
    }
}

Answer 1

学习使用布局管理器
JComboBox不会将ArrayList（或Collection）作为可行参数（可能需要Object[]或Vector）
movieName，movieRating，movieTime，moviePrice都未初始化，因为您在创建UI后初始化它们。
JTextField#setText不会将ArrayList作为可行参数
学习从控制台或IDE中读取应用程序的输出
学习使用调试器 - 它可以为您节省数小时的挫折和烦恼;）

在组合框中获取文本文件

1 个答案: