Question

我声明的类并设置变量。每次用户激活按钮时，都会设置变量userQuestion。目的是使它可以在下一个类中用来重新解决这个问题。但是，似乎没有设置userQuestion变量。对于凌乱的代码感到抱歉，它是在Eclipse中使用Window Builder制作的。

https://pastebin.com/azP6SbRa

import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Insets;


public class createprojecte extends JFrame {

private JPanel contentPane;
private JTextField textField;
private JButton btnWhatIsYour;
private JButton btnWhereDidYour;
private JButton btnWhatWasThe;
private JButton btnWhoIsYour;
private JButton btnWhatIsYour_1;
private JButton btnWhatIsYour_2;



public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                createprojecte frame = new createprojecte();
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    })
    ;
}

String userQuestion;

public createprojecte() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 450, 300);
    contentPane = new JPanel();
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    setContentPane(contentPane);
    GridBagLayout gbl_contentPane = new GridBagLayout();
    gbl_contentPane.columnWidths = new int[]{424, 0};
    gbl_contentPane.rowHeights = new int[]{20, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    gbl_contentPane.columnWeights = new double[]{0.0, Double.MIN_VALUE};
    gbl_contentPane.rowWeights = new double[]{0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE};
    contentPane.setLayout(gbl_contentPane);

    textField = new JTextField();
    textField.setText("Choose what security option you want:");
    textField.setColumns(10);
    GridBagConstraints gbc_textField = new GridBagConstraints();
    gbc_textField.insets = new Insets(0, 0, 5, 0);
    gbc_textField.anchor = GridBagConstraints.NORTH;
    gbc_textField.fill = GridBagConstraints.HORIZONTAL;
    gbc_textField.gridx = 0;
    gbc_textField.gridy = 0;
    contentPane.add(textField, gbc_textField);


    btnWhatIsYour = new JButton("What is your mother's maiden name?");
    btnWhatIsYour.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            input frame = new input();
            frame.setVisible(true);
            String userQuestion = "What is your mother's maiden name?";
            frame.SetUserQuestion(userQuestion);
        }
    });
    GridBagConstraints gbc_btnWhatIsYour = new GridBagConstraints();
    gbc_btnWhatIsYour.insets = new Insets(0, 0, 5, 0);
    gbc_btnWhatIsYour.gridx = 0;
    gbc_btnWhatIsYour.gridy = 2;
    contentPane.add(btnWhatIsYour, gbc_btnWhatIsYour);

    btnWhereDidYour = new JButton("Where did your parents meet?");
    btnWhereDidYour.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            input frame = new input();
            frame.setVisible(true);
            String userQuestion = "Where did your parents meet?";

        }
    });
    GridBagConstraints gbc_btnWhereDidYour = new GridBagConstraints();
    gbc_btnWhereDidYour.insets = new Insets(0, 0, 5, 0);
    gbc_btnWhereDidYour.gridx = 0;
    gbc_btnWhereDidYour.gridy = 3;
    contentPane.add(btnWhereDidYour, gbc_btnWhereDidYour);

    btnWhatWasThe = new JButton("What was the first street you lived on?");
    btnWhatWasThe.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            input frame = new input();
            frame.setVisible(true);
            String userQuestion = "What was the first street you lived on?";
        }
    });
    GridBagConstraints gbc_btnWhatWasThe = new GridBagConstraints();
    gbc_btnWhatWasThe.insets = new Insets(0, 0, 5, 0);
    gbc_btnWhatWasThe.gridx = 0;
    gbc_btnWhatWasThe.gridy = 4;
    contentPane.add(btnWhatWasThe, gbc_btnWhatWasThe);

    btnWhoIsYour = new JButton("Who is your favorite music group?");
    btnWhoIsYour.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            input frame = new input();
            frame.setVisible(true);
            String userQuestion = "Who is your favorite music group?";
        }
    });
    GridBagConstraints gbc_btnWhoIsYour = new GridBagConstraints();
    gbc_btnWhoIsYour.insets = new Insets(0, 0, 5, 0);
    gbc_btnWhoIsYour.gridx = 0;
    gbc_btnWhoIsYour.gridy = 5;
    contentPane.add(btnWhoIsYour, gbc_btnWhoIsYour);

    btnWhatIsYour_1 = new JButton("What is your favorite book?");
    btnWhatIsYour_1.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            input frame = new input();
            frame.setVisible(true);
            String userQuestion = "What is your favorite book?";
        }
    });
    GridBagConstraints gbc_btnWhatIsYour_1 = new GridBagConstraints();
    gbc_btnWhatIsYour_1.insets = new Insets(0, 0, 5, 0);
    gbc_btnWhatIsYour_1.gridx = 0;
    gbc_btnWhatIsYour_1.gridy = 6;
    contentPane.add(btnWhatIsYour_1, gbc_btnWhatIsYour_1);

    btnWhatIsYour_2 = new JButton("What is your favorite sports team?");
    btnWhatIsYour_2.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            input frame = new input();
            frame.setVisible(true);
            String userQuestion = "What is your favorite sports team?";
        }
    });
    GridBagConstraints gbc_btnWhatIsYour_2 = new GridBagConstraints();
    gbc_btnWhatIsYour_2.insets = new Insets(0, 0, 5, 0);
    gbc_btnWhatIsYour_2.gridx = 0;
    gbc_btnWhatIsYour_2.gridy = 7;
    contentPane.add(btnWhatIsYour_2, gbc_btnWhatIsYour_2);
}
}

我尝试访问变量的类。 https://pastebin.com/vb6MWeba

import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import java.awt.GridBagLayout;
import javax.swing.JTextField;
import java.awt.GridBagConstraints;
import javax.swing.JPasswordField;
import java.awt.Insets;

public class input extends JFrame {
private JTextField txtWhatIsThe;

/**
 * Launch the application.
 */ 
public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                input frame = new input();
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}
String userQuestion;

public void SetUserQuestion(String question)
{
    this.userQuestion = question;
}

public input() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 450, 300);
    getContentPane().setLayout(null);
    GridBagLayout gridBagLayout = new GridBagLayout();
    gridBagLayout.columnWidths = new int[]{0, 0};
    gridBagLayout.rowHeights = new int[]{0, 0, 0, 0};
    gridBagLayout.columnWeights = new double[]{1.0, Double.MIN_VALUE};
    gridBagLayout.rowWeights = new double[]{0.0, 0.0, 0.0, Double.MIN_VALUE};
    getContentPane().setLayout(gridBagLayout);

    txtWhatIsThe = new JTextField();
    txtWhatIsThe.setText(userQuestion );
    GridBagConstraints gbc_txtWhatIsThe = new GridBagConstraints();
    gbc_txtWhatIsThe.insets = new Insets(0, 0, 5, 0);
    gbc_txtWhatIsThe.fill = GridBagConstraints.HORIZONTAL;
    gbc_txtWhatIsThe.gridx = 0;
    gbc_txtWhatIsThe.gridy = 0;
    getContentPane().add(txtWhatIsThe, gbc_txtWhatIsThe);
    txtWhatIsThe.setColumns(10);
}

}

Answer 1

在某些听众中，你并没有真正将问题置于框架中：

btnWhatIsYour_1.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        input frame = new input();
        frame.setVisible(true);
        String userQuestion = "What is your favorite book?";
        // Missing setter
    }
});

变量“userQuestion”没有值。我试图从另一个类访问它，但它不会返回任何内容

1 个答案: