calculator.java

一个简单的计算器,实现了简单的加减乘除功能.

clear=true; 
first=1; 
} 
if (temp==c) 
{ 
text.setText("0."); ; 
clear=true; 
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)//第二坛判断 
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) 
{ //导师，此方法参考书中例子 
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 
{//导师,本进制类参考了CSMD类转换例子 

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); 
} 


}