而不是将JOptionPane输入存储为变量并传递给方法。你们能把变量直接输入到方法中吗？

Question

我试图提示用户使用JOptionPane从对话框中输入两个数字，然后调用一个方法返回它们的值

我正在尝试使用integer将JOptionPane返回的字符串值转换为整数。parseInt（）但我无法让它工作

有什么提示我哪里出了问题吗

谢谢

    /**
 * 
 */
package methodsWeekThree;

import javax.swing.JOptionPane;

/**
 * @author kylemoffett
 *
 */
public class ReturnMethodExcersiseOne {

    /**
     * @param args
     */
    public static void main(String[] args) {

        System.out.println("Please input num1 and hit enter: ");

        System.out.println("Please input num2 and hit enter: ");

        System.out.println(additionCircuit(Integer.parseInt(JOptionPane.showInputDialog("Input num1:"))),
                Integer.parseInt(JOptionPane.showInputDialog("Input num2:")));

    }// end main

    /**
     * This method adds two numbers and returns the value
     * 
     * @param num1 - first number to add
     * @param num2 - second number to add
     * @return - total of the addition
     */
    public static int additionCircuit(int num1, int num2) {

        int total;

        total = num1 + num2;

        return total;

    }// end additionCircuit

}// end class

Answer 1

试试看：

public class ReturnMethodExcersiseOne {

    /**
     * @param args
     */
    public static void main(String[] args) {

        System.out.println("Please input num1 and hit enter: ");
        int num1 = Integer.parseInt(JOptionPane.showInputDialog("Input num2:"));
        System.out.println("Please input num2 and hit enter: ");
        int num2 = Integer.parseInt(JOptionPane.showInputDialog("Input num2:"));
        
        System.out.println(additionCircuit(num1, num2));

    }// end main

    /**
     * This method adds two numbers and returns the value
     * 
     * @param num1 - first number to add
     * @param num2 - second number to add
     * @return - total of the addition
     */
    public static int additionCircuit(int num1, int num2) {

        int total;

        total = num1 + num2;

        return total;

    }// end additionCircuit

}// end class

解释：

1. 最好先存储JOptionPane值，然后再将其传递给additionCircuit方法，以避免括号问题

Answer 2

括号的嵌套是错误的

System.out.println(additionCircuit(Integer.parseInt(JOptionPane.showInputDialog("Input num1:")),
Integer.parseInt(JOptionPane.showInputDialog("Input num2:"))));

Answer 3

这里有一个替代方法，它只显示一次JOptionPane，而不是两次

import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.WindowConstants;

public class ReturnMethodExcersiseOne {
    public static void main(String[] args) {

        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        JLabel num1Label = new JLabel("num1");
        panel.add(num1Label, gbc);
        gbc.gridx = 1;
        JTextField num1TextField = new JTextField(6);
        panel.add(num1TextField, gbc);
        gbc.gridx = 0;
        gbc.gridy = 1;
        JLabel num2Label = new JLabel("num2");
        panel.add(num2Label, gbc);
        gbc.gridx = 1;
        JTextField num2TextField = new JTextField(6);
        panel.add(num2TextField, gbc);
        JOptionPane optionPane = new JOptionPane(panel);
        JDialog dlg = optionPane.createDialog("Prompt");
        dlg.addWindowListener(new WindowAdapter() {
            @Override
            public void windowDeactivated(WindowEvent e) {
                int num1 = Integer.parseInt(num1TextField.getText());
                int num2 = Integer.parseInt(num2TextField.getText());
                System.out.println(additionCircuit(num1, num2));
                ((JDialog) e.getSource()).dispose();
            }
            
            @Override
            public void windowClosing(WindowEvent windowEvent) {
                int num1 = Integer.parseInt(num1TextField.getText());
                int num2 = Integer.parseInt(num2TextField.getText());
                System.out.println(additionCircuit(num1, num2));
            }
        });
        dlg.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        dlg.setSize(200, 200);
        dlg.setVisible(true);
    }// end main

    /**
     * This method adds two numbers and returns the value
     * 
     * @param num1 - first number to add
     * @param num2 - second number to add
     * @return - total of the addition
     */
    public static int additionCircuit(int num1, int num2) {
        int total;
        total = num1 + num2;
        return total;
    }// end additionCircuit
}