用Java设计一个简单的计算器。

最新问答

• 0密星猛龙0

  说实在的，你写的这个计算器不怎么样。特别是布局。
  我给你一个很简单的吧。你自己学习一下。。
  
  import java.awt.*;
  import java.awt.event.*;
  /**
  *
  * @author zzj
  *
  */
  public class Jisuanqi extends WindowAdapter {
  Panel p1 = new Panel();
  Panel p2 = new Panel();
  Panel p3 = new Panel();
  TextField txt;
  private Button[] b = new Button[17];
  private String ss[] = { "7", "8", "9", "+", "4", "5", "6", "-", "1", "2",
  "3", "*", "清空", "0", "=", "/", "关闭" };
  static double a;
  static String s, str;//定义变量 创建对像
  
  public static void main(String args[]) {
  (new Jisuanqi()).frame();
  }
  
  public void frame() {
  Frame fm = new Frame("简单计算器");
  for (int i = 0; i <= 16; i++) {
  b[i] = new Button(ss[i]);
  }
  for (int i = 0; i <= 15; i++) {
  p2.add(b[i]);
  } //创建按钮 并到P2
  b[16].setBackground(Color.yellow);
  txt = new TextField(15);
  txt.setEditable(false);
  for (int i = 0; i <= 16; i++) {
  b[i].addActionListener(new buttonlistener());//
  }
  b[16].addActionListener(new close());
  fm.addWindowListener(this);
  fm.setBackground(Color.red);
  p1.setLayout(new BorderLayout());
  p1.add(txt, "North");
  p2.setLayout(new GridLayout(4, 4));
  p3.setLayout(new BorderLayout());
  p3.add(b[16]);
  fm.add(p1, "North");
  fm.add(p2, "Center");
  fm.add(p3, "South");
  fm.pack();
  fm.setVisible(true);//都是些窗中设置 相关组件和
  }
  
  public void windowClosing(WindowEvent e) {
  System.exit(0);//退出系统
  }
  
  class buttonlistener implements ActionListener {//编写 通过按键得出给果
  public void actionPerformed(ActionEvent e) {
  Button btn = (Button) e.getSource();
  if (btn.getLabel() == "=") {
  jisuan();
  str = String.valueOf(a);
  txt.setText(str);
  s = "";
  } else if (btn.getLabel() == "+") {
  jisuan();
  txt.setText("");
  s = "+";
  } else if (btn.getLabel() == "-") {
  jisuan();
  txt.setText("");
  s = "-";
  } else if (btn.getLabel() == "/") {
  jisuan();
  txt.setText("");
  s = "/";
  
  } else if (btn.getLabel() == "*") {
  jisuan();
  txt.setText("");
  s = "*";
  } else {
  txt.setText(txt.getText() + btn.getLabel());
  
  if (btn.getLabel() == "清空")
  txt.setText("");
  }
  }
  
  public void jisuan() {//编写具体计算方法
  if (s == "+")
  a += Double.parseDouble(txt.getText());
  else if (s == "-")
  a -= Double.parseDouble(txt.getText());
  else if (s == "*")
  a *= Double.parseDouble(txt.getText());
  else if (s == "/")
  a /= Double.parseDouble(txt.getText());
  else
  a = Double.parseDouble(txt.getText());
  }
  }
  }
  
  class close implements ActionListener {//退出
  public void actionPerformed(ActionEvent e) {
  System.exit(0);
  }
  }

  浏览 253赞 147时间 2023-10-07
• 弱智好儿童

  import java.awt.*;
  import java.awt.event.*;
  import java.applet.*;
  import javax.swing.JOptionPane;
  
  public class Calculator extends Applet implements ActionListener{
  	Button backButton=new Button("退格");
  	Button clearButton=new Button("清除");
  	Panel p1 = new Panel(new FlowLayout());
  	Panel p2 = new Panel(new GridLayout(2,1));
  	Panel p3 = new Panel(new GridLayout(4,5,5,5));
  	TextField t=new TextField("0");
  	float num1=0;
  	char ch='#';boolean can=false;
  	public void init(){
  	t.setFont(new Font("宋体",Font.BOLD,25));
  	backButton.setFont(new Font("黑体",Font.BOLD,15));
  	backButton.setForeground(Color.red);
  	clearButton.setFont(new Font("黑体",Font.BOLD,15));
  	clearButton.setForeground(Color.red);
  	p1.add(backButton);
  	p1.add(clearButton);
  	backButton.addActionListener(this);
  	clearButton.addActionListener(this);
  	p2.add(t);
  	p2.add(p1);
  	p2.setBackground(Color.black);
  	p3.setBackground(Color.black);
  	this.setLayout(new BorderLayout());
  	this.add(p2,"North");
  	this.add(p3,"Center");
  	String buttonStr = "789/A456*B123-C0.D+=";
  	for (int i = 0; i < buttonStr.length(); i++)
  	this.addButton(p3,buttonStr.substring(i, i + 1));
  	}
  	private void addButton(Container c, String s)
  	{Button b = new Button(s);
  	if (s.equals("A"))
  		b.setLabel("sqrt");
  	else if (s.equals("B"))
  		b.setLabel("1/x");
  	else if (s.equals("C"))
  		b.setLabel("%");
  	else if (s.equals("D"))
  		b.setLabel("+/-");
  	b.setForeground(Color.blue);
  	b.setFont(new Font("黑体",Font.BOLD,15));
  	c.add(b);
  	b.addActionListener(this);
  }
  public void actionPerformed(ActionEvent e){
  	String act=e.getActionCommand();
  	if(e.getSource()==backButton){
  		if(t.getText().length()>1)t.setText(t.getText().substring(0, t.getText().length()-1));
  		else t.setText("0");
  	return;}
  	if(e.getSource()==clearButton){t.setText("0");ch='#';return;}
  	if(act.equals("+/-")){
  		if(t.getText().charAt(0)!='-')t.setText("-"+t.getText());
  		else t.setText(t.getText().substring(1));return;
  	}
  	if(act.equals(".")){t.setText(t.getText()+act);return;}
  	if(act!="1/x"&&act.charAt(0)>='0'&&act.charAt(0)<='9'){
  		if(can){t.setText(act);can=false;}
  		else{try{if(Float.parseFloat(t.getText())==0)
  			{if(t.getText().equals("0."))t.setText(t.getText()+act);
  				else t.setText(act);
  			return;
  			}
  		else {t.setText(t.getText()+act);return;}
  		}catch(NumberFormatException e1){
  			JOptionPane.showMessageDialog(null, "输入格式错误！", "警告！",
  JOptionPane.ERROR_MESSAGE);return;}
  		}
  		}
  
  	if(act.equals("+")||act.equals("-")||act.equals("*")||act.equals("/")||act.equals("%")){
  		if(ch!='#'){try{num1=cacu(num1,ch,Float.parseFloat(t.getText()));
  					t.setText(String.valueOf(num1));ch=act.charAt(0);can=true;return;
  		}catch(NumberFormatException e1){JOptionPane.showMessageDialog(null, "输入格式错误！", "警告！",
  JOptionPane.ERROR_MESSAGE);return;}
  			}
  	else{try{num1=Float.parseFloat(t.getText());
  			ch=act.charAt(0);can=true;return;
  		}catch(NumberFormatException e1){JOptionPane.showMessageDialog(null, "输入格式错误！", "警告！",
  JOptionPane.ERROR_MESSAGE);return;}
  		}
  	}
  	if(act.equals("sqrt")){try{float num=(float)Math.sqrt(Float.parseFloat(t.getText()));
  	t.setText(String.valueOf(num));can=true;return;
  	}catch(NumberFormatException e1){JOptionPane.showMessageDialog(null, "输入格式错误！", "警告！",
  JOptionPane.ERROR_MESSAGE);return;}
  	}
  	if(act.equals("1/x")){try{float num=1/Float.parseFloat(t.getText());
  	t.setText(String.valueOf(num));can=true;return;
  	}catch(NumberFormatException e1){JOptionPane.showMessageDialog(null, "输入格式错误！", "警告！",
  JOptionPane.ERROR_MESSAGE);return;}
  	catch(ArithmeticException e1){JOptionPane.showMessageDialog(null, "除0错误！", "警告！",
  JOptionPane.ERROR_MESSAGE);return;}
  	}
  	if(act.equals("=")){can=true;
  		try{if(ch=='#')return;
  		float num=Float.parseFloat(t.getText());
  		num1=cacu(num1,ch,num);
  		t.setText(String.valueOf(num1));
  		ch='#';return;
  		}catch(NumberFormatException e1){JOptionPane.showMessageDialog(null, "输入格式错误！", "警告！",
  JOptionPane.ERROR_MESSAGE);return;}
  	}
  }
  public float cacu(float a,char c,float b){
  		float sum;
  		switch(c){
  			case '+':sum=a+b;break;
  			case '-':sum=a-b;break;
  			case '*':sum=a*b;break;
  			case '/':if(b==0){JOptionPane.showMessageDialog(null, "除0错误！", "警告！",
  JOptionPane.ERROR_MESSAGE);return 0;}sum=a/b;break;
  			case '%':if(b==0){JOptionPane.showMessageDialog(null, "除0错误！", "警告！",
  JOptionPane.ERROR_MESSAGE);return 0;}sum=a%b;break;
  			default:return 0;
  		}
  		return sum;
  	}
  }

  浏览 376赞 64时间 2023-09-30
• Lemonice柠檬冰

  无聊写了个，修复了下Bug：

  import java.awt.event.ActionEvent;
  import java.awt.event.ActionListener;
  import javax.swing.JButton;
  import javax.swing.JFrame;
  import javax.swing.JLabel;
  import javax.swing.JOptionPane;
  import javax.swing.JTextField;
  
  public class Calculate extends JFrame implements ActionListener {
  
      private static final long serialVersionUID = 1L;
  
      private JButton plus, reduce, multiply, divice, reset;
      private JTextField one, two, result;
      private boolean device_falg = false;
  
      private final int width = 400, height = 300;
  
      public Calculate() {
          super("修改密");
          this.setLayout(null);
          this.setSize(width, height);
          init();
          Layout();
      }
  
      public void init() {
          plus = new JButton("加   ");
          reduce = new JButton("减    ");
          multiply = new JButton("乘   ");
          divice = new JButton("除    ");
          reset = new JButton("清空");
          one = new JTextField();
          two = new JTextField();
          result = new JTextField();
      }
  
      public void Layout() {
          this.add(new JLabel("第一个数")).setBounds(20, 10, 60, 80);
          this.add(one).setBounds(100, 38, 100, 25);
          this.add(new JLabel("第二个数")).setBounds(20, 40, 60, 80);
          this.add(two).setBounds(100, 70, 100, 25);
          this.add(new JLabel("结果")).setBounds(20, 85, 60, 80);
          this.add(result).setBounds(100, 110, 100, 25);
  
          this.add(plus).setBounds(70, 170, 80, 25);
          this.add(reduce).setBounds(200, 170, 80, 25);
          this.add(multiply).setBounds(70, 200, 80, 25);
          this.add(divice).setBounds(200, 200, 80, 25);
  
          this.add(reset).setBounds(300, 220, 80, 25);
  
          plus.addActionListener(this);
          reduce.addActionListener(this);
          multiply.addActionListener(this);
          divice.addActionListener(this);
          reset.addActionListener(this);
  
          this.setVisible(true);
          this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
      }
  
      public boolean Format() {
          boolean FLAG = false;
          boolean flag = false;
          String one = this.one.getText().toString().trim();
          String two = this.two.getText().toString().trim();
  
          if (one == null || one.equals("") || two == null || two.equals("")) {
              JOptionPane.showMessageDialog(getParent(), "请输入完整信息!");
              FLAG = false;
              flag = true;
          }
  
          boolean boll_1 = one.matches("[d]{1,100}");
          boolean boll_2 = two.matches("[d]{1,100}");
          boolean boll_3 = one.matches("[d]{1,100}+[.]+[d]{1,100}");
          boolean boll_4 = two.matches("[d]{1,100}+[.]+[d]{1,100}");
          if (flag) {
              return false;
          }
          if ((boll_1 && boll_2) || (boll_3 && boll_4) || (boll_1 && boll_4)
                  || (boll_3 && boll_2)) {
              FLAG = true;
          } else {
              JOptionPane.showMessageDialog(getParent(), "请输入数字!");
              FLAG = false;
          }
  
          if (FLAG && device_falg) {
              if (Double.parseDouble(two) == 0) {
                  JOptionPane.showMessageDialog(getParent(), "被除数不能为0!");
                  FLAG = false;
                  device_falg=false;
              }
          }
  
          return FLAG;
      }
  
      public double Plus(double one, double two) {
          return one + two;
      }
  
      public double Multiply(double one, double two) {
          return one * two;
      }
  
      public double Divice(double one, double two) {
          return one / two;
      }
  
      public double Reduce(double one, double two) {
          return one - two;
      }
  
      public void Clear() {
          one.setText("");
          two.setText("");
          result.setText("");
      }
  
      @Override
      public void actionPerformed(ActionEvent e) {
          Object o = e.getSource();
          if (o == reset) {
              Clear();
              return;
          }
          if (o == divice) {
              device_falg = true;
          }
          if (!Format()) {
              return;
          }
          double one = Double.parseDouble(this.one.getText());
          double two = Double.parseDouble(this.two.getText());
          double result = 0;
          if (o == plus) {
              result = Plus(one, two);
          } else if (o == reduce) {
              result = Reduce(one, two);
          } else if (o == multiply) {
              result = Multiply(one, two);
          } else if (o == divice) {
              result = Divice(one, two);
          }
          this.result.setText("" + result);
      }
      public static void main(String[] args) {
          new Calculate();
      }
  }

  浏览 482赞 96时间 2022-12-04
• 早秋2013

  比一楼的简单

  package com.isoftstone.baidu;
  
  import java.awt.event.ActionEvent;
  import java.awt.event.ActionListener;
  
  import javax.swing.JButton;
  import javax.swing.JFrame;
  import javax.swing.JLabel;
  import javax.swing.JOptionPane;
  import javax.swing.JPanel;
  import javax.swing.JTextField;
  
  public class CalcDemo extends JFrame {
  
      private static final long serialVersionUID = 111111L;
      private JLabel label1 = new JLabel();
      private JLabel label2 = new JLabel();
      private JLabel label3 = new JLabel();
      private JTextField field1 = new JTextField();
      private JTextField field2 = new JTextField();
      private JTextField field3 = new JTextField();
      private JButton button1 = new JButton();
      private JButton button2 = new JButton();
      private JButton button3 = new JButton();
      private JButton button4 = new JButton();
  
      public static void main(String[] args) {
          new CalcDemo();
      }
  
      public CalcDemo() {
          super("简易计算器");
          try {
              init();
          } catch (Exception e) {
              e.printStackTrace();
          }
      }
  
      private void init() {
          this.setSize(300, 300);
          label1.setText("第一个数：");
          label2.setText("第二个数：");
          label3.setText("结果：");
          button1.setText("加法");
          button2.setText("减法");
          button3.setText("乘法");
          button4.setText("除法");
          label1.setBounds(10, 10, 100, 22);
          label2.setBounds(10, 35, 100, 22);
          label3.setBounds(10, 60, 100, 22);
          field1.setBounds(110, 10, 100, 22);
          field2.setBounds(110, 35, 100, 22);
          field3.setBounds(110, 60, 100, 22);
          button1.setBounds(10, 85, 100, 22);
          button2.setBounds(110, 85, 100, 22);
          button3.setBounds(110, 110, 100, 22);
          button4.setBounds(10, 110, 100, 22);
          button1.addActionListener(new ActionListener() {
  
              public void actionPerformed(ActionEvent e) {
                  calculate(1);
              }
          });
          button2.addActionListener(new ActionListener() {
  
              public void actionPerformed(ActionEvent e) {
                  calculate(2);
              }
          });
          button3.addActionListener(new ActionListener() {
  
              public void actionPerformed(ActionEvent e) {
                  calculate(3);
              }
          });
          button4.addActionListener(new ActionListener() {
  
              public void actionPerformed(ActionEvent e) {
                  calculate(4);
              }
          });
          JPanel panel = (JPanel) this.getContentPane();
          panel.setLayout(null);
          panel.add(label1);
          panel.add(label2);
          panel.add(label3);
          panel.add(field1);
          panel.add(field2);
          panel.add(field3);
          panel.add(button1);
          panel.add(button2);
          panel.add(button3);
          panel.add(button4);
          this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          this.setResizable(false);
          this.setLocationRelativeTo(null);
          this.setVisible(true);
  
      }
  
      private void calculate(int operators) {
          try {
              double num1 = Double.parseDouble(field1.getText());
              double num2 = Double.parseDouble(field2.getText());
              switch (operators) {
                  case 1:
                      field3.setText((num1 + num2) + "");
                      break;
                  case 2:
                      field3.setText((num1 - num2) + "");
                      break;
                  case 3:
                      field3.setText((num1 * num2) + "");
                      break;
                  case 4:
                      field3.setText((num1 / num2) + "");
                      break;
                  default:
                      break;
              }
          } catch (NumberFormatException e) {
              JOptionPane.showMessageDialog(this, "请输入正确的数值!!!", "警告", 1);
          }
      }
  }

  浏览 398赞 72时间 2022-03-24
• 涅槃0531

  百度一下很多的，何况这代也不难，自己理一下很也能弄出来，给button， 中取两个文本框的值，将两个文本框的值转化为int(这时候可能会有异常，trycatch处理)，在进行运算，最后将结果放入结果文本框中

  浏览 296赞 135时间 2021-09-22