Question

我正在尝试创建一个将二进制转换为十进制，十进制转换为二进制的applet。我已经编写了每个人的小程序，但现在我想创建一个使用单选按钮选择用户想要进行的转换，然后让转换按钮执行转换。我现在卡住了，不太确定从哪里开始......目前还没有编译。

我还希望包含一个向上或向下指向的箭头，具体取决于所选的单选按钮...我已尝试将所述箭头的Unicode实现为JLabel，但他们不接受字符，怎么会去关于这个？

非常感谢您的帮助。

这是我目前一堆乱糟糟的代码......

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，您正在重新声明方法内的类字段，并有效地“遮蔽”字段使其不可见。该字段是“二进制”

这是您最初申报的地方：

public class BinaryAndDecimalConvert extends JApplet {
   private JPanel bPanel;

   //...

   private JTextField binary;

这是你影子的地方：

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：不要为与重要类字段同名的方法提供局部变量。

接下来，您尝试在String变量binaryNumber：

上调用setText()

binaryNumber.setText(decimal1);

String没有这样的方法，所以摆脱这个方法调用。

带有单选按钮的二进制到十进制小程序

1 个答案: