带单选按钮的二进制到十进制小程序

Question

我正在尝试制作一个将二进制转换为十进制并将十进制转换为二进制的小程序。我已经编写了针对每个人的小程序，但现在我想制作一个使用单选按钮来选择用户想要进行的转换，然后让转换按钮执行该转换的小程序。我现在被卡住了，不太确定从这里去哪里......它目前没有编译。

我还想包含一个向上或向下的箭头，具体取决于所选的单选按钮...我尝试将所述箭头的 Unicode 实现到 JLabel 中，但它们不接受字符，怎么办？关于这个？

非常感谢您的任何帮助。

这是我目前乱七八糟的代码...

编辑：

import java.util.Scanner;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;

public class binaryAndDecimalConvert extends JApplet
{
    private JPanel bPanel;
    private JPanel dPanel;
    private JPanel buttonPanel;
    private JPanel radioPanel;
    private JPanel arrowPanel;

    private JLabel arrowUp;
    private JLabel arrowDown;

    private JTextField binaryTxt;
    private JTextField decimalTxt;

    private ButtonGroup radioButtonGroup;
    private JRadioButton binaryConvButton;
    private JRadioButton decimalConvButton;

    public void init()
    {
        Font font = new Font("display font", Font.BOLD, 15);



        //build the panels
        buildBpanel();
        buildArrowPanel();
        buildDpanel();
        buildButtonPanel();
        buildRadioPanel();



        //create Layout Manager.
        setLayout(new GridLayout(5, 1));

        // Add the panels to the content pan.
        add(bPanel);
        add(arrowPanel);
        add(dPanel);
        add(buttonPanel);
        add(radioPanel);
    }


    private void buildDpanel()
    {
        dPanel = new JPanel();
        dPanel.setBackground(Color.pink);
        JLabel message2 = new JLabel("Decimal Number: ");

        decimalTxt = new JTextField(15);

        dPanel.setLayout(new FlowLayout(FlowLayout.LEFT));

        dPanel.add(message2);
        dPanel.add(decimalTxt);
    }



    private void buildBpanel()
    {
        //create the panel
        bPanel = new JPanel();
        bPanel.setBackground(Color.pink);
        //create a label to display a mssage
        JLabel message1 = new JLabel("Binary Number: ");

        //create a text field for the binary number
        binaryTxt = new JTextField(15);


        //create a layout manager for the panel
        bPanel.setLayout(new FlowLayout(FlowLayout.LEFT));

        ///add the label and text field to the panel
        bPanel.add(message1);
        bPanel.add(binaryTxt);
    }

    public void buildRadioPanel()
    {
        radioPanel = new JPanel();
        radioPanel.setBackground(Color.pink);

        binaryConvButton = new JRadioButton("Binary to Decimal");
        decimalConvButton = new JRadioButton("Decimal to Binary");

        radioButtonGroup = new ButtonGroup();
        radioButtonGroup.add(binaryConvButton);
        radioButtonGroup.add(decimalConvButton);

        binaryConvButton.addActionListener(new RadioButtonListener());
        decimalConvButton.addActionListener(new RadioButtonListener());

        binaryConvButton.addActionListener(new RadioButtonListener());
        decimalConvButton.addActionListener(new RadioButtonListener());

        radioPanel.add(binaryConvButton);
        radioPanel.add(decimalConvButton);

        binaryConvButton.setEnabled(true);
    }

    public void buildArrowPanel()
    {
        arrowPanel = new JPanel();

        arrowUp = new JLabel("\u2191");
        arrowDown = new JLabel("\u2193");

        arrowPanel.setBackground(Color.pink);

        arrowPanel.add(arrowDown);

    }

    private class RadioButtonListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            if(e.getSource() == binaryConvButton)
            {
                arrowPanel.add(arrowUp);
            }
            else if(e.getSource() == decimalConvButton)
                arrowPanel.add(arrowDown);




        }
    }



    private void buildButtonPanel()
    {
        buttonPanel = new JPanel();
        buttonPanel.setBackground(Color.pink);
        JButton convButton = new JButton("Convert");

        convButton.addActionListener(new ButtonListener());
        buttonPanel.add(convButton);

    }

    private class ButtonListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            //binary to decimal conversion
            String decimalNum= "";
            int decimal1 = 0;
            String binaryNum = "";
            int power = 1;
            int dec;

            if(e.getSource() == decimalConvButton)
            {
            binaryNum=binaryTxt.getText();
            for(int i = 1; i <= binaryNum.length(); i++)
            {
                if(binaryNum.charAt(binaryNum.length()-i) == '1')
                {
                    decimal1 = (decimal1 + power);
                }
            power = (power*2);
            }
            decimalNum = Integer.toString(decimal1);
            decimalTxt.setText(decimalNum);
            }

            //decimal to binary
            if(e.getSource() == binaryConvButton)
            {
                  dec = Integer.parseInt(decimalTxt.getText());
                  while (dec != 0)
                  {
                        binaryNum = (dec % 2) + binaryNum;
                        dec /= 2;
                  }
                binaryTxt.setText(binaryNum);

            }
        }


    }
}

Answer 1

您遇到的一个问题是，您在方法内部重新声明了一个类字段，并有效地“隐藏”了该字段，使其不可见。该字段是“二进制”

这是您最初声明它的地方：

public class BinaryAndDecimalConvert extends JApplet {
   private JPanel bPanel;

   //...

   private JTextField binary;

这里是你阴影的地方：

private class ButtonListener implements ActionListener {
  public void actionPerformed(ActionEvent e) {
     String decimalNum = "";
     int decimal1 = 0;
     String binaryNum = "";
     int power = 1;

     String binary;  // **** redeclared here ****

     if (binaryToDec = true) {

        binaryNum = binary.getText(); // so this won't work

解决方案：不要将方法的局部变量与重要的类字段同名。

接下来，您尝试在字符串变量 binaryNumber 上调用 setText()：

binaryNumber.setText(decimal1);

String没有这样的方法，所以去掉这个方法调用。