calculator.java

用Java编写的计算器程序

			clear = false;
		}

		if (temp == backspace) {//退格
			String s = text.getText();
			text.setText("");
			for (int i = 0; i < s.length() - 1; i++) {
				char a = s.charAt(i);
				text.setText(text.getText() + a);
			}
		}

		if (temp == ce) {
			text.setText("0.");
			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);
	}

}