如何从 JFrame 表单中获取输入？

Question

我正在尝试获取我在 JFrame 表单中提交的输入并将其存储在 arraylist 中。当我的 ActionEvent 发生时，我不确定如何获取我在文本字段中输入的内容。谁能告诉我怎么做？

我的表单目前看起来像

这是我的代码：

public class SpringDemo {
    private static void createAndShowGUI() {
        final String[] labels = {"Bill: ", "Last Top Up Date: ", "Same Network? "};
        int labelsLength = labels.length;

        //Create and populate the panel.
        JPanel p = new JPanel(new SpringLayout());
        for (int i = 0; i < labelsLength; i++) {
            JLabel l = new JLabel(labels[i], JLabel.TRAILING);
            p.add(l);
            JTextField textField = new JTextField(10);
            l.setLabelFor(textField);
            p.add(textField);
        }
        JButton button = new JButton("Submit");
        p.add(new JLabel());
        p.add(button);

        //Lay out the panel.
        SpringUtilities.makeCompactGrid(p,
                                    labelsLength + 1, 2, //rows, cols
                                    7, 7,        //initX, initY
                                    7, 7);       //xPad, yPad

        button.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                //Execute when button is pressed
                System.out.println("Test");
            }
        });  
        //Create and set up the window.
        JFrame frame = new JFrame("SpringForm");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Set up the content pane.
        p.setOpaque(true);  //content panes must be opaque
        frame.setContentPane(p);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

Answer 1

为此，您的createAndShowGUI 方法应如下所示：

private static void createAndShowGUI() {
    final String[] labels = {"Bill: ", "Last Top Up Date: ", "Same Network? "};
    int labelsLength = labels.length;
    final JTextField[] textField = new JTextField[labels.length];
    //Create and populate the panel.
    JPanel p = new JPanel(new SpringLayout());
    for (int i = 0; i < labelsLength; i++) {
        JLabel l = new JLabel(labels[i], JLabel.TRAILING);
        p.add(l);
        textField[i] = new JTextField(10);
        l.setLabelFor(textField[i]);
        p.add(textField[i]);
    }
    JButton button = new JButton("Submit");
    p.add(new JLabel());
    p.add(button);

    //Lay out the panel.
    SpringUtilities.makeCompactGrid(p,
                                    labelsLength + 1, 2, //rows, cols
                                    7, 7,        //initX, initY
                                    7, 7);       //xPad, yPad

    button.addActionListener(new ActionListener() {

        public void actionPerformed(ActionEvent e)
        {
            for (int i = 0 ; i < labels.length ; i++)
            {
                System.out.println(labels[i]+"->"+textField[i].getText());
            }
        }
    });  
    //Create and set up the window.
    JFrame frame = new JFrame("SpringForm");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    //Set up the content pane.
    p.setOpaque(true);  //content panes must be opaque
    frame.setContentPane(p);

    //Display the window.
    frame.pack();
    frame.setVisible(true);
}

Answer 2

将JTextFields 保存在一个列表中，并在您的动作监听器中引用它们。

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SpringLayout;

public class SpringDemo {
    private static void createAndShowGUI() {
        final String[] labels = { "Bill: ", "Last Top Up Date: ",
                "Same Network? " };
        int labelsLength = labels.length;
        final List<JTextField> textFields = new ArrayList<JTextField>();

        // Create and populate the panel.
        JPanel p = new JPanel(new SpringLayout());
        for (int i = 0; i < labelsLength; i++) {
            JLabel l = new JLabel(labels[i], JLabel.TRAILING);
            p.add(l);
            JTextField textField = new JTextField(10);
            textFields.add(textField);
            l.setLabelFor(textField);
            p.add(textField);
        }
        JButton button = new JButton("Submit");
        p.add(new JLabel());
        p.add(button);

        // Lay out the panel.
        SpringUtilities.makeCompactGrid(p, labelsLength + 1, 2, // rows, cols
                7, 7, // initX, initY
                7, 7); // xPad, yPad

        button.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                // Execute when button is pressed
                System.out.println("Test");
                for (JTextField jTextField : textFields) {
                    String s = jTextField.getText();
                }
            }
        });
        // Create and set up the window.
        JFrame frame = new JFrame("SpringForm");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Set up the content pane.
        p.setOpaque(true); // content panes must be opaque
        frame.setContentPane(p);

        // Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        // Schedule a job for the event-dispatching thread:
        // creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

Answer 3

你只需要使用

textField.getText();

除非我错了。

老实说，虽然这可能不适用于每个人，但我只是将它们作为单独的文本字段而不是通过 for 循环创建新的文本字段

JTextField a = new JTextField();
and so on.....