calculator.java

JAVA做的比较简单的计算器

   first=1;
  }
  
  if(temp==num0)
   {  
    if(clear==false)//判断是否点击了符号位
    text.setText("");
    text.setText(text.getText()+"0");
   }
  
  if(temp==num1)
   {    
    if(clear==false)
    text.setText("");
    text.setText(text.getText()+"1");
    clear=true;//第二次不在清空（前二句）
   }
  
  if(temp==num2)
   {    
    if(clear==false)
    text.setText("");
    text.setText(text.getText()+"2");
    clear=true;
   }
  
  if(temp==num3)
   {    
    if(clear==false)
    text.setText("");
    text.setText(text.getText()+"3");
    clear=true;
   }
  
  if(temp==num4)
   {    
    if(clear==false)
    text.setText("");
    text.setText(text.getText()+"4");
    clear=true;
   }
  
  if(temp==num5)
   {
    if(clear==false)
    text.setText("");
    text.setText(text.getText()+"5");
    clear=true;
   }
  
  if(temp==num6)
   {
    if(clear==false)
    text.setText("");
    text.setText(text.getText()+"6");
    clear=true;
   }
  if(temp==num7)
   {
    if(clear==false)
    text.setText("");
    text.setText(text.getText()+"7");
    clear=true;
   }
  
  if(temp==num8)
   {
    if(clear==false)
    text.setText("");
    text.setText(text.getText()+"8");
    clear=true;
   }
  
  if(temp==num9)
   {
    if(clear==false)
    text.setText("");
    text.setText(text.getText()+"9");
    clear=true;
   }
   if(temp==aa)
   {
    text.setText(text.getText()+"A");
   }
  if(temp==bb)
   {
    text.setText(text.getText()+"B");
   }
  
  if(temp==cc)
   {
    text.setText(text.getText()+"C");
   }
  
  if(temp==dd)
   {
    text.setText(text.getText()+"D");
   }
  
  if(temp==ee)
   {
    text.setText(text.getText()+"E");
   } 
  if(temp==ff)
   {
    text.setText(text.getText()+"F");
   }
   if(temp==dian)
   {
    clickable=true;
    for (int i = 0; i < text.getText().length(); i++) 
   if ('.' == text.getText().charAt(i)) 
   { 
   clickable=false; 
   break; 
   } //第一层判断是否里面含有小数点;
    
    if(clickable==true)//第二层判断
    text.setText(text.getText()+".");
    
   }
   
  try
  { 
   if(temp==jia)
   {//加法
    qian=Double.parseDouble(text.getText());
    fuhao="+";
    clear=false;
   }
   if(temp==jian)
   {
    qian=Double.parseDouble(text.getText());
    fuhao="-";
    clear=false;
    ;
    
   }
   if(temp==cheng)
   {
    qian=Double.parseDouble(text.getText());
    fuhao="*";
    clear=false;
        
   }
   if(temp==chu)
   {
    qian=Double.parseDouble(text.getText());
    fuhao="/";
    clear=false;
        
   }
   if(temp==deng)
   {
    double ss=Double.parseDouble(text.getText());
    text.setText("");
    if(fuhao=="+")
    text.setText(qian+ss+"");
    if(fuhao=="-")
    text.setText(qian-ss+"");
    if(fuhao=="*")
    text.setText(qian*ss+"");
    if(fuhao=="/")
    text.setText(qian/ss+"");
    clear=false;//要清空前一次的数据
    ;
    
   }
   
   if(temp==kai)
   {     
  String s = text.getText(); 
  if (s.charAt(0) == '-')
  { 
   text.setText("负数不能开根号"); 
  } 
  else 
  text.setText(Double.toString(java.lang.Math.sqrt(Double.parseDouble(text.getText())))); 
  clear=false;
  }
  
  if(temp==diao)
  {
    
   if (text.getText().charAt(0) == '0'&&text.getText().length() == 1)
    { 
    text.setText("除数不能为零"); 
    } 
  else 
  { 
  boolean isDec = true; 
   int i, j, k; 
   String s = Double.toString(1 / Double.parseDouble(text.getText())); 
   for (i = 0; i < s.length(); i++) 
   if (s.charAt(i) == '.') 
   break; 
   for (j = i + 1; j < s.length(); j++) 
   if (s.charAt(j) != '0')
   { 
   isDec = false; 
   break; 
   } 
   if (isDec == true)
   { 
   String stemp = ""; 
   for (k = 0; k < i; k++) 
    stemp += s.charAt(k); 
    text.setText(stemp); 
   } 
   else 
   text.setText(s); 
   } 
 
    clear=false;
  }
  if(temp==qiuyi)
  {
   text.setText("0");
   clear=false;
  }
  if (temp == fu) 
  { 
   boolean isNumber = true; 
   String s = text.getText(); 
   for (int i = 0; i < s.length(); i++) 
   if (! (s.charAt(i) >= '0' && s.charAt(i) <= '9' || s.charAt(i) == '.' || 
   s.charAt(i) == '-'))
        { 
     isNumber = false; 
     break; 
     } 
   if (isNumber == true)
    { 
   //如果当前字符串首字母有'-'号,代表现在是个负数,再按下时,则将首符号去掉 
     if (s.charAt(0) == '-') 
     { 
     text.setText(""); 
     for (int i = 1; i < s.length(); i++)
         { 
       char a = s.charAt(i); 
       text.setText(text.getText() + a); 
           } 
     } 
      //如果当前字符串第一个字符不是符号，则添加一个符号在首字母处 
   else 
   text.setText('-' + s); 
   } 
  } 
  
 }
 catch(Exception eee)
 {
  System.out.println("运算时,首先输入数字或字符");
  text.setText("运算出错");
  clear=false;
 }
  
  
   
 }

 

 class WindowDestroyer extends WindowAdapter
 {//退出窗口动作
  public void windowClosing(WindowEvent e)
  {
  System.exit(0);
  }
 }
 
class objConversion
{
 
 public void objConversion ()
 {
 }
 
 public String decDec (int decNum)
 {//10
  
  String strDecNum = Integer.toString(decNum);
  
  for (int i = strDecNum.length(); i < 3; i++)
  {
   strDecNum = "0" + strDecNum;
  }
  
 // return strDecNum;
  return invert (strDecNum, 5);
  
 }
 
 public String decHex (int decNum)
 {//10 to 16
  
  String strHexNum = "";
  int currentNum = 0;
  
  while (decNum != 0)
  {
   
   if (decNum > 15)
   {
    
    currentNum = decNum % 16;
    decNum /= 16;
    
   }
   else
   {
    
    currentNum = decNum;
    decNum = 0;
    
   }
   
   switch (currentNum)
   {
    
    case 15: strHexNum += "F";
       break;
    case 14: strHexNum += "E";
       break;
    case 13: strHexNum += "D";
       break;
    case 12: strHexNum += "C";
       break;
    case 11: strHexNum += "B";
       break;
    case 10: strHexNum += "A";
       break;
    default: strHexNum += Integer.toString(currentNum);
       break;
       
   }
   
  }
   
  return invert (strHexNum, 2);
   
 }
  
 public String decOct (int decNum)
 {//10 to 8
  
  String strOctNum = "";
  
  while (decNum != 0)
  {
   
   if (decNum > 7)
   {
    
    strOctNum += Integer.toString(decNum % 8);
    decNum /= 8;
    
   }
   else
   {
    
    strOctNum += Integer.toString(decNum);
    decNum = 0;
    
   }
   
  }
  
  return invert (strOctNum, 3);
  
 }
 
 public String decBin (int decNum)
 {//10 to 2
  
  String strBinNum = "";
  
  while (decNum != 0)
  {
   
   if (decNum > 1)
   {
    
    strBinNum += Integer.toString(decNum % 2);
    decNum /= 2;
    
   }
   else
   {
    
    strBinNum += Integer.toString(decNum);
    decNum = 0;
    
   }
   
  }
  
  return invert (strBinNum, 8);
  
 }
 
 private String invert (String strNum, int minLength) //转换长度
 {  
  
  String answer = "";
  int length = strNum.length();
  
  if (length < minLength)
  {
   
   for (int padding = (minLength - length); padding > 0; padding--)
   {
    answer += "0";
   }
   
  }
  
  for (int i = length; i > 0; i--)
  {
   answer += strNum.charAt (i - 1);
  }
  
  return answer;
  
 }
 
}
 
 
 public static void main(String arg[])//产生窗口
 {
  calculator win = new calculator(); 
  win.setVisible(true);
 }
}