answerd /= Double.parseDouble(textAnswer.getText());
					break;
				default:
					answerd = Double.parseDouble(textAnswer.getText());
				}
			  textAnswer.setText("");
			  prekey = key = 3;
			}
		    }
	      //'='操作
	      if (temp == buttonEqual && clickable == true) 
		{
		  //如果連續(xù)按'=',則進(jìn)行連續(xù)運(yùn)算
		  if (prekey == 5) 
		    {
		      if (key == 0)
			{
			  answerd += vard;
			  textAnswer.setText(df.format(answerd));
	 		 }
		      if (key == 1)
			{
			  answerd -= vard;
			  textAnswer.setText(df.format(answerd));
			 }
		      if (key == 2) 
			{
			  answerd *= vard;
			  textAnswer.setText(df.format(answerd));
			}
		      if (key == 3) 
			{
			  if (Double.parseDouble(textAnswer.getText()) == 0) 
			    {
				textAnswer.setText("除數(shù)不能為零");
				clickable = false;
			     }
			  else 
			    {
				answerd /= vard;
				textAnswer.setText(df.format(answerd));
			     }
			}
		    }
		  else
		     {
			vard = Double.parseDouble(textAnswer.getText());
			if (key == 0) 
			  {
			    prekey = -1;
			    answerd += Double.parseDouble(textAnswer.getText());
			    textAnswer.setText(df.format(answerd));
			  }
			if (key == 1)
			  {
			    prekey = -1;
			    answerd -= Double.parseDouble(textAnswer.getText());
          		    textAnswer.setText(df.format(answerd));
        		  }
         		if (key == 2)
			  {
      			    prekey = -1;
    			    answerd *= Double.parseDouble(textAnswer.getText());
          		    textAnswer.setText(df.format(answerd));
       			   }
        		if (key == 3)
			  { 
          		    prekey = -1;
          		    if (Double.parseDouble(textAnswer.getText()) == 0) 
			     {
       				textAnswer.setText("除數(shù)不能為零");
           			clickable = false;
         		      }
         		    else 
			     {
          			answerd /= Double.parseDouble(textAnswer.getText());
         			textAnswer.setText(df.format(answerd));
        		      }
       			   }
     		   }
     		 prekey = 5;
  		}
   	      //'%'操作，對(duì)第二個(gè)操作數(shù)除以100
   	      if (temp == buttonMod && clickable == true) 
		{
    		  if (answerd == 0) 
		    {
    		      String s = textAnswer.getText();
        	      textAnswer.setText(s);
    		     }
		  else 
		    {
  		      boolean isDot = false;
      		      for (int i = 0; i < textAnswer.getText().length(); i++)
   			if ('.' == textAnswer.getText().charAt(i))
			  {
         		     isDot = true;
           		     break;
         		  }
       		      //如果是double數(shù)，除100
       		      if (isDot == true) 
			{
      			  double dtemp = Double.parseDouble(textAnswer.getText());
        		  dtemp = dtemp / 100.0;
        		  textAnswer.setText(Double.toString(dtemp));
       			}
       		      else 
			{
       			  //如果是int數(shù)但能被100整除，則去掉末尾兩個(gè)零
        		  if (Integer.parseInt(textAnswer.getText()) % 100 == 0) 
		 	    {
        			int itemp = Integer.parseInt(textAnswer.getText());
				itemp /= 100;
         			textAnswer.setText(Integer.toString(itemp));
          		     }
      			   //如果是int數(shù)，但不能被100整除，則按double數(shù)處理
         		  else 
			    {
      				double dtemp = Double.parseDouble(textAnswer.getText());
      				dtemp = dtemp / 100.0;
     				textAnswer.setText(Double.toString(dtemp));
         		     }
     			}
   		    }
   	        }
   	      //開(kāi)根號(hào)運(yùn)算
  	      if (temp == buttonSqrt && clickable == true) 
		{
     		  String s = textAnswer.getText();
      		  if (s.charAt(0) == '-') 
		    {
         		textAnswer.setText("負(fù)數(shù)不能開(kāi)根號(hào)");
        		clickable = false;
      		    }
  		  else
     			textAnswer.setText(Double.toString(java.lang.Math.sqrt
			(Double.parseDouble(textAnswer.getText()))));
    		}
    	      //倒數(shù)運(yùn)算
     	      if (temp == buttonDao && clickable == true) 
		{
     		  if (textAnswer.getText().charAt(0) == '0' &&textAnswer.getText().length() == 1)
		    {
        		textAnswer.setText("零不能求倒數(shù)");
         		clickable = false;
       		     }
     		  else 
		    {
        		boolean isDec = true;
       			int i, j, k;
        		String s = Double.toString(1 / Double.parseDouble(textAnswer.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);
        			textAnswer.setText(stemp);
         		   }
       			else
       				textAnswer.setText(s);
        	     }
     		}
      	     //按下'+/-'按鈕時(shí)處理
    	      if (temp == buttonAddAndSub && clickable == true) 
		{
     		    boolean isNumber = true;
    		    String s = textAnswer.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) 
			   {
    				//如果當(dāng)前字符串首字母有'-'號(hào),代表現(xiàn)在是個(gè)負(fù)數(shù),再按下時(shí),則將首符號(hào)去掉
      				if (s.charAt(0) == '-') 
				  {
        				textAnswer.setText("");
        				for (int i = 1; i < s.length(); i++)
					   {
            					char a = s.charAt(i);
          					textAnswer.setText(textAnswer.getText() + a);
        				    }
      				   }
       				//如果當(dāng)前字符串第一個(gè)字符不是符號(hào)，則添加一個(gè)符號(hào)在首字母處
       				else
         			   textAnswer.setText('-' + s);
    			    }
    		}
    	     //計(jì)算器有關(guān)內(nèi)存操作
   	     //'MC'的操作，將內(nèi)存清0
   	      if (temp == buttonMC && clickable == true) 
		{
      		   memoryd = memoryi = 0;
      		    textMemory.setText("");
    		}
     	     //'MS'的操作，將當(dāng)前文本框內(nèi)容保存入內(nèi)存，顯示'M'
  	     if (temp == buttonMS && clickable == true) 
		{
      		    boolean isDot = false;
      		    textMemory.setText("   M");
      	 	    for (int i = 0; i < textAnswer.getText().length(); i++)
      		    if ('.' == textAnswer.getText().charAt(i)) 
		      {
       			isDot = true;
      			break;
    		       }
   	           //如果是double,則存入memoryd(double存儲(chǔ)器)
      		    if (isDot == true) 
      		      {
     			memoryd = Double.parseDouble(textAnswer.getText());
          		memoryi = 0; //保證存儲(chǔ)器中存放最新的值
      			}
     		    //如果是int,則存入memoryi(int存儲(chǔ)器)
      		    else 
		      {
      			memoryi = Integer.parseInt(textAnswer.getText());
       			memoryd = 0; //保證存儲(chǔ)器中存放最新的值
      			}
     		 }
    	     //'MR'的操作，將存儲(chǔ)器中的信息輸出
     	      if (temp == buttonMR && clickable == true) 
		{
    		   if (memoryd != 0)
       			textAnswer.setText(Double.toString(memoryd));
     		   if (memoryi != 0)
      			textAnswer.setText(Integer.toString(memoryi));
   		}
    	     //'M+'的功能，將當(dāng)前文本框里的數(shù)據(jù)和存儲(chǔ)器中數(shù)據(jù)相加后，再存入存儲(chǔ)器
    	      if (temp == buttonMAdd && clickable == true) 
     		{
     		    boolean isDot = false;
   		    for(int i = 0; i < textAnswer.getText().length(); i++)
      			if ('.' == textAnswer.getText().charAt(i)) 
			  {
         			isDot = true;
           			break;
       			   }
      		    if (memoryi != 0) 
		      { //存儲(chǔ)中是一個(gè)int型數(shù)
      			if (isDot == false) //被加數(shù)是一個(gè)int型數(shù)
        		    memoryi += Integer.parseInt(textAnswer.getText());
      			else 
			  { //被加數(shù)是一個(gè)double型數(shù)，則將int存儲(chǔ)器中數(shù)傳入double存儲(chǔ)器與當(dāng)前數(shù)相加，			    //　int存儲(chǔ)器清零
     			     memoryd = memoryi + Double.parseDouble(textAnswer.getText());
      			    memoryi = 0;
        		   }
      		       }
       		    else
       			memoryd += Double.parseDouble(textAnswer.getText());
   		}
     	     //按下'Backspace'鍵，利用循環(huán)將當(dāng)前字符串中的最后一個(gè)字母刪除
   	     if (temp == buttonBk && clickable == true) 
		{
      		   String s = textAnswer.getText();
      	  	   textAnswer.setText("");
   		   for (int i = 0; i < s.length() - 1; i++) 
		      {
     			char a = s.charAt(i);
      			textAnswer.setText(textAnswer.getText() + a);
    		      }
 		}
     	     //按下'CE'按鈕，將當(dāng)前文本框內(nèi)數(shù)據(jù)清除
    	     if (temp == buttonCe) 
		{
   		   textAnswer.setText("");
    		   clickable = true;
  		}
   	     //按下'C'按鈕，文本框內(nèi)數(shù)據(jù)清除，同時(shí)var,answer清0
  	     if (temp == buttonC) 
		{
    		   vard = answerd = 0;
   		   textAnswer.setText("");
    		   clickable = true;
  		}
    	     //按下'復(fù)制'菜單欄
    	     if (temp == copyItem) 
		{
      		   copy = textAnswer.getText();
  		}
     	     //按下'粘貼'菜單欄
    	     if (temp == pasteItem) 
		{
      		   textAnswer.setText(copy);
    		}
     	     if (temp == sItem) 
		{
    		   JOptionPane.showMessageDialog(panel, "當(dāng)前是標(biāo)準(zhǔn)型計(jì)算器，\n科學(xué)型計(jì)算器有待更		   			新。");
    		}
     	     //按下'幫助主題'菜單欄
    	     if (temp == topHelp) 
		{
   		   JOptionPane.showMessageDialog(panel, scrollHelp);
   		}
      	 	//按下'數(shù)字分組'菜單欄
     	     if (temp == numberGroup) 
		{
   		   if (numberGroup.getText().compareTo("   數(shù)字分組(I)") == 0)
   			numberGroup.setText("√數(shù)字分組(I)");
    		   else
   			numberGroup.setText("   數(shù)字分組(I)");
    		}
    	     //按下'關(guān)于'菜單欄
      	     if (temp == aboutCal) 
		{
   		   JOptionPane.showMessageDialog(panel, "計(jì)算器1.00版\n開(kāi)發(fā)者：樓競(jìng)");
  		}
 	    }
 	  //輸入中如果有操作非法，比如按下兩次'+'，捕獲異常
  	  catch (Exception e) 
		{
   		   textAnswer.setText("操作非法");
    		   clickable = false;
  		}
	}
  //主函數(shù)
  public static void main(String args[]) 
	{
  		new Calculator();
 	}
 }