[Java] 用java写了个计算器（再次吃饱没事干）

墨蓝 2022-10-11 01:19 141阅读 0赞

import java.awt.*;
    import java.awt.event.*;
    public class Calculation extends WindowAdapter implements ActionListener
    {
        
      double dResult=0;
      double dNowInput=0;
      double dMemory;
      int  n=0; //记载小数位数
      int  nOperation=1; // 记录运算符类型
      int  nBitsNum=0;  //记录总共输入的位数
      boolean alreadyHaveDot=false; //已经有小数点？
      boolean keyAvailable=true;
      boolean alreadyClickedEqueal=false; //是否按下过"="?
      boolean isTempNowInput=false; //是否在计算出结果后直接按运算符将结果赋给了当前输入值？
      
      Frame f;
      Panel p1,p2,p3,p4,p5,p6;
      TextField tf1,tf2;
      Button b1,b2,b3,b4,b5,b6,b7,b8,b9,b0;
      Button bDiv,bSqrt,bMulti,bMinus,bPercent,bPlus,bReciprocal,bEqual,bDot,bNegative;
      Button bBackspace,bCE,bC,bMR,bMS,bMC,bM;
        
      public void display()
      {
        
        f=new Frame("计算器");
        f.setSize(283,213);
        f.setLocation(400,400);
        f.setBackground(Color.LIGHT_GRAY);
        f.setResizable(false);
        
        f.setLayout(new BorderLayout(3,3));
        
        p1=new Panel(new GridLayout(1,3,5,5));  //用于存放backspace,ce,c三键
        p2=new Panel(new GridLayout(4,5,5,5)); //用于存放数字区及附近共20键, 此处间隙设置可能不合理，以后调整
        p3=new Panel(new GridLayout(5,1,5,5)); //用于存放MC,MR,MS,M+键及显示M状态文本框,此处间隙设置可能不合理，以后调整
        p4=new Panel(new FlowLayout()); //用于存放p1,p2
        p5=new Panel(new FlowLayout());
        p6=new Panel(new FlowLayout());
        p4.add(p1);
        p4.add(p2);
        
        tf1=new TextField(35);      //存放显示区
        tf1.setText("0.");
        tf1.setEditable(false);
        p5.add(tf1);
        f.add(p5,BorderLayout.NORTH);
        f.add(p4,BorderLayout.CENTER);
        f.add(p3,BorderLayout.WEST);
        
        b1=new Button("1");
        b2=new Button("2");
        b3=new Button("3");
        b4=new Button("4");
        b5=new Button("5");
        b6=new Button("6");
        b7=new Button("7");
        b8=new Button("8");
        b9=new Button("9");
        b0=new Button("0");
        
        b1.addActionListener(this);
        b2.addActionListener(this);
        b3.addActionListener(this);
        b4.addActionListener(this);
        b5.addActionListener(this);
        b6.addActionListener(this);
        b7.addActionListener(this);
        b8.addActionListener(this);
        b9.addActionListener(this);
        b0.addActionListener(this);
        
        bDiv=new Button("/");
        bSqrt=new Button("sqrt");
        bMulti=new Button("*");
        bMinus=new Button("-");
        bPercent=new Button("%");
        bPlus=new Button("+");
        bReciprocal=new Button("1/x");
        bEqual=new Button("=");
        bDot=new Button(".");
        bNegative=new Button("+/-");
        
        bDiv.addActionListener(this);
        bSqrt.addActionListener(this);
        bMulti.addActionListener(this);
        bMinus.addActionListener(this);
        bPercent.addActionListener(this);
        bPlus.addActionListener(this);
        bReciprocal.addActionListener(this);
        bEqual.addActionListener(this);
        bDot.addActionListener(this);
        bNegative.addActionListener(this);
        
        p2.add(b7);
        p2.add(b8);
        p2.add(b9);
        p2.add(bDiv);
        p2.add(bSqrt);
        p2.add(b4);
        p2.add(b5);
        p2.add(b6);
        p2.add(bMulti);
        p2.add(bPercent);
        p2.add(b1);
        p2.add(b2);
        p2.add(b3);
        p2.add(bMinus);
        p2.add(bReciprocal);
        p2.add(b0);
        p2.add(bNegative);
        p2.add(bDot);
        p2.add(bPlus);
        p2.add(bEqual);
        
        bBackspace=new Button("Backspace");
        bCE=new Button("CE");
        bC=new Button("C");
        
        bBackspace.addActionListener(this);
        bCE.addActionListener(this);
        bC.addActionListener(this);
        
        p1.add(bBackspace); 
        p1.add(bCE);
        p1.add(bC);
        
        tf2=new TextField(2);
        tf2.setEnabled(false);
        tf2.setBackground(Color.LIGHT_GRAY);
        bMC=new Button("MC");
        bMR=new Button("MR");
        bMS=new Button("MS");
        bM=new Button("M+");
        
        bMC.addActionListener(this);
        bMR.addActionListener(this);
        bMS.addActionListener(this);
        bM.addActionListener(this);
        
        p6.add(tf2);
        p3.add(p6);
        p3.add(bMC);
        p3.add(bMR);
        p3.add(bMS);
        p3.add(bM);
        
        f.setVisible(true);
        f.addWindowListener(this);
        
      }
      public void actionPerformed(ActionEvent e)
      {
         
        //key 0 to 9
        if(this.keyAvailable && e.getActionCommand().length()==1 && e.getActionCommand().compareTo("0")>=0 && e.getActionCommand().compareTo("9")<=0)
        {
        
        if(this.isTempNowInput)
        {
        
          this.dNowInput=0;
          this.isTempNowInput=false;
        }
        this.nBitsNum++; 
        if(this.alreadyHaveDot==false)
          this.dNowInput=this.dNowInput*10+Double.parseDouble(e.getActionCommand());
        else
        {
         
          double temp=Double.parseDouble(e.getActionCommand());
          for(int i=this.n;i<0;i++)
          {
             
          temp*=0.1;
          }
          this.dNowInput+=temp;
          this.n--;
        }
        this.tf1.setText(Double.toString(this.dNowInput));
        }
        // key dot
        if(this.keyAvailable && e.getActionCommand()==".")
        {
        
        if(this.alreadyHaveDot==false)
        {
        
          this.nBitsNum++;
          this.alreadyHaveDot=true;
          this.n=-1; 
        }
        }
        //key "+","-","*","/"
        if(this.keyAvailable && e.getActionCommand()=="+" || e.getActionCommand()=="-" || e.getActionCommand()=="*" || e.getActionCommand()=="/")
        {
         
        if(this.alreadyClickedEqueal)
        {
        
          this.dNowInput=this.dResult;
          this.isTempNowInput=true;
        }
        else
        {
        
          switch(this.nOperation)
          {
        
          case 1: this.dResult+=this.dNowInput; break;
          case 2: this.dResult-=this.dNowInput; break;
          case 3: this.dResult*=this.dNowInput; break;
          case 4:
          {
        
            if(this.dNowInput==0)
            {
        
            tf1.setText("除数不能为零");
            this.keyAvailable=false;
            }
            else this.dResult=this.dResult/this.dNowInput;
          }
          }
          if(this.keyAvailable)tf1.setText(Double.toString(this.dResult));
          this.dNowInput=0; 
        }   
        if(e.getActionCommand()=="+")
        {
         
          this.nOperation=1; 
        }
        if(e.getActionCommand()=="-")
        {
         
          this.nOperation=2;
        }
        if(e.getActionCommand()=="*")
        {
        
          this.nOperation=3;
        }
        if(e.getActionCommand()=="/")
        {
        
          this.nOperation=4;
        }
        this.nBitsNum=0;
        this.alreadyClickedEqueal=false;
        }
        // key "+/-" 
        if(this.keyAvailable && e.getActionCommand()=="+/-")
        {
        
        this.dNowInput=0-this.dNowInput;
        tf1.setText(Double.toString(this.dNowInput));   
        }
        // key "C" 
        if(e.getActionCommand()=="C")
        {
        
        this.nBitsNum=0;
        this.dResult=0;
        this.dNowInput=0;
        this.alreadyHaveDot=false;
        this.n=0;
        this.nOperation=1;
        this.keyAvailable=true;
        this.alreadyClickedEqueal=false;
        tf1.setText("0.");
        }
        // key "CE"
        if(e.getActionCommand()=="CE")
        {
        
        this.nBitsNum=0;
        this.dNowInput=0;
        this.alreadyHaveDot=false;
        this.n=0;
        this.nOperation=1;
        this.keyAvailable=true;
        tf1.setText("0.");
        }
        
        // key "sqrt"
        if(this.keyAvailable && e.getActionCommand()=="sqrt")
        {
        
        if(this.alreadyClickedEqueal)
        {
        
          if(this.dResult>=0)
          {
        
          this.dResult=Math.sqrt(this.dResult);
          tf1.setText(Double.toString(this.dResult));
          }
          else
          {
        
          tf1.setText("函数输入无效");
          this.keyAvailable=false;
          }
        }
        else
        {
        
          if(this.dNowInput>=0)
          {
        
          this.dNowInput=Math.sqrt(this.dNowInput);
          tf1.setText(Double.toString(this.dNowInput));
          }
          else
          {
        
          tf1.setText("函数输入无效");
          this.keyAvailable=false;
          }
        } 
        }
        // key "1/x"
        if(this.keyAvailable && e.getActionCommand()=="1/x")
        {
        
        if(this.dNowInput==0)
        {
        
          tf1.setText("除数不能为零");
          this.keyAvailable=false;
        }
        else
        {
        
          this.dNowInput=1/this.dNowInput;
          tf1.setText(Double.toString(this.dNowInput));
        }
        }
        // key "="
        if(this.keyAvailable && e.getActionCommand()=="=")
        {
        
        this.alreadyClickedEqueal=true;
        switch(this.nOperation)
        {
        
          case 1: this.dResult+=this.dNowInput; break;
          case 2: this.dResult-=this.dNowInput; break;
          case 3: this.dResult*=this.dNowInput; break;
          case 4:
          {
        
          if(this.dNowInput==0)
          {
        
            tf1.setText("除数不能为零");
            this.keyAvailable=false;
          }
          else this.dResult=this.dResult/this.dNowInput;
          }
        }
        if(this.keyAvailable)tf1.setText(Double.toString(this.dResult));  
        }
        // key "MS"
        if(this.keyAvailable && e.getActionCommand()=="MS")
        {
        
        this.dMemory=this.dNowInput;
        if(this.dMemory!=0)
          tf2.setText("M");
        }
        // key "MC"
        if(this.keyAvailable && e.getActionCommand()=="MC")
        {
        
        this.dMemory=0;
        tf2.setText("");
        }
        // key "MR"
        if(this.keyAvailable && e.getActionCommand()=="MR")
        {
        
        this.dNowInput=this.dMemory;
        tf1.setText(Double.toString(this.dNowInput));
        }
        // key "M+"
        if(this.keyAvailable && e.getActionCommand()=="M+")
        {
        
        this.dMemory+=this.dNowInput;
        if(this.dMemory!=0)
          tf2.setText("M");
        else tf2.setText("");
        }
        // key "%"
        if(this.keyAvailable && e.getActionCommand()=="%")
        {
        
        this.dNowInput=(this.dResult*this.dNowInput)/100;
        tf1.setText(Double.toString(this.dNowInput));
        }
        // key "Backspace"
        if(this.keyAvailable && e.getActionCommand()=="Backspace")
        {
        
        if(!this.alreadyClickedEqueal){
        
          if(this.dNowInput!=0)
          {
        
          if(this.alreadyHaveDot)
          {
        
            if(this.n==-1)
            {
        
            this.alreadyHaveDot=false;
            this.n=0; 
            }
            else
            {
        
            String str,str1;
            str=tf1.getText();
            str1=str.substring(0,this.nBitsNum-1);
            this.nBitsNum--;
            this.n++;
            this.dNowInput=Double.parseDouble(str1);
            tf1.setText(Double.toString(this.dNowInput));      
            }
          }
          else
          {
        
            int temp;
            temp=(int)(this.dNowInput/10);
            this.dNowInput=(double)temp;
            tf1.setText(Double.toString(this.dNowInput));
          }
          }
        }
        }
      }
      public static void main(String args[])
      {
        
        Calculation cal=new Calculation();
        cal.display();
      }
      public void windowClosing(WindowEvent e)
      {
        
        System.exit(0);
      }
    }