計算器（android）

對計算器的一些說明：

此計算器比較簡陋，可以實現加減乘除這些運算，並能實現連續運算。對小數運算進行了優化了，避免了小數在計算時出現誤差。

主界面：

calculator的main_activity.java;

import android.R.string;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;


public class MainActivity extends Activity {
	TextView tv=null;
	private  double number_one=0.0,number_two=0.0;
	String  arithmetic1=" ",arithmetic2=" ";
	
	private Button button_zone;
	private Button button_one;
	private Button button_two;
	private Button button_three;
	private Button button_four;
	private Button button_five;
	private Button button_six;
	private Button button_seven;
	private Button button_eight;
	private Button button_nine;
	private Button button_clean;
	
	private Button button_equate;
	private Button button_tiny;
	private Button button_addition;
	private Button button_subtraction;
	private Button button_multiplication;
	private Button button_division;
	
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		button_zone=(Button)findViewById(R.id.But_zo);
		button_one=(Button)findViewById(R.id.But_on);
		button_two=(Button)findViewById(R.id.But_tw);
		button_three=(Button)findViewById(R.id.But_th);
		button_four=(Button)findViewById(R.id.But_fo);
		button_five=(Button)findViewById(R.id.But_fi);
		button_six=(Button)findViewById(R.id.But_si);
		button_seven=(Button)findViewById(R.id.But_se);
		button_eight=(Button)findViewById(R.id.But_ei);
		button_nine=(Button)findViewById(R.id.But_ni);
		
		button_equate =(Button)findViewById(R.id.But_eq);
		button_tiny =(Button)findViewById(R.id.But_ti);
		button_addition=(Button)findViewById(R.id.But_ad);
		button_subtraction=(Button)findViewById(R.id.But_su);
		button_multiplication=(Button)findViewById(R.id.But_mu);
	    button_division=(Button)findViewById(R.id.But_di);
	    
		button_clean=(Button)findViewById(R.id.But_cl);
		
		tv = (TextView)findViewById(R.id.ed_tv);
			
		button_equate.setOnClickListener (Listener);
		button_tiny.setOnClickListener (Listener);
		
		button_addition.setOnClickListener (Listener);
		button_subtraction.setOnClickListener(Listener);
		button_multiplication.setOnClickListener(Listener);
		button_division.setOnClickListener(Listener);
		
		button_five.setOnClickListener(Listener);
		button_five.setOnClickListener(Listener);
		button_zone.setOnClickListener(Listener);
		button_one.setOnClickListener (Listener);	
		button_two.setOnClickListener(Listener);
		button_three.setOnClickListener(Listener);
		button_four.setOnClickListener(Listener);
		button_five.setOnClickListener(Listener);
		button_six.setOnClickListener(Listener);
		button_seven.setOnClickListener(Listener);
		button_eight.setOnClickListener(Listener);
		button_nine.setOnClickListener(Listener);
		button_clean.setOnClickListener(Listener);
	}	




 public OnClickListener Listener = new OnClickListener()
  {
	public void onClick(View v)
    {
	Button btn=(Button)v;
	switch ( btn.getId() ) 
	{ 
	case R.id.But_zo:
		if (arithmetic2.equals("=")) {
			clean();	
		}
		tv_changed(0);
		break;
	case R.id.But_on:
		if (arithmetic2.equals("=")) {
			clean();	
		}
		tv_changed(1);
		break;	
	case R.id.But_tw:
		if (arithmetic2.equals("=")) {
			clean();	
		}
		tv_changed(2);
		break;	
	case R.id.But_th:	
		if (arithmetic2.equals("=")) {
			clean();	
		}
		tv_changed(3);
		break;		
	case R.id.But_fo:	
		if (arithmetic2.equals("=")) {
			clean();	
		}
		tv_changed(4);
		break;
	case R.id.But_fi:	
		if (arithmetic2.equals("=")) {
			clean();	
		}
		tv_changed(5);
		break;
	case R.id.But_si:
		if (arithmetic2.equals("=")) {
			clean();	
		}
		tv_changed(6);
		break;
	case R.id.But_se:
		if (arithmetic2.equals("=")) {
			clean();	
		}
		tv_changed(7);
		break;
	case R.id.But_ei:
		if (arithmetic2.equals("=")) {
			clean();	
		}
		tv_changed(8);
		break;
	case R.id.But_ni:
		if (arithmetic2.equals("=")) {
			clean();	
		}
		tv_changed(9);
		break;
	case R.id.But_eq:
		tv_changed("=");
		break;
	case R.id.But_ad:
		tv_changed("+");
		break;
	case R.id.But_mu:
		tv_changed("*");
		break;	
	case R.id.But_su:
		tv_changed("-");
		break;
	case R.id.But_di:
		tv_changed("/");
		break;
	case R.id.But_ti:
		tv_changed(".");
		break;
	case R.id.But_cl:
		tv_changed("clean");
		break;
	default:
		break;
	  } 	
   }
	private void tv_changed(int i) {
		String string = tv.getText().toString();
		string += i;
		tv.setText(string);
			
	}
	private void tv_changed(String str) {
		  if ( str.equals(".") ) {
				
					  String str1 = tv.getText().toString()+".";
						 tv.setText(str1);						
		}
		
	      if(str.equals("clean"))
	      {  clean(); }
		if( str =="+"||str =="-"||str =="*"||str =="/" )
		{
				String str1 = tv.getText().toString();
				 tv.setText(str1);
				 number_one= Double.parseDouble(str1)*10000;
				System.out.println("numberone="+number_one);
				 tv.setText(" ");
				 arithmetic1 = str;
				 System.out.println("arithmetic1="+arithmetic1);
				 tv.setText(str);
				 tv.setText(" ");
				 	
		}
		if (str=="=") 
		 {
			String str1 = tv.getText().toString();
			 tv.setText(str1);
			 number_two= Double.parseDouble(str1)*10000;
			System.out.println("numbertwo="+number_two);
			 tv.setText(" ");
			 arithmetic2 = str;
			 System.out.println("arithmetic2="+arithmetic2);
			 tv.setText(str);
			 arithmetic(number_one,number_two,arithmetic1);
		 }
	}
	private void clean() {
      tv.setText(" ");
   	  number_two=0.0;
   	  arithmetic2=" ";
   	  System.out.println("numberone="+number_one);
   	  System.out.println("numbertwo="+number_two);
	}


 };
protected void arithmetic(double number_one2, double number_two2,
		String arithmetic1)
{
	            tv.setText(" ");
	   if (arithmetic1.equals("+")) {
		   number_one=(number_one2+ number_two2)/10000;
	    	 String s = String.valueOf(number_one);
	    	 tv.setText(s);	  
	  }
	   else if (arithmetic1.equals("-")) {
		   number_one=(number_one2 - number_two2)/10000;
	    	 String s1 = String.valueOf(number_one);
	    	 tv.setText(s1);	  
	}
	   else  if (arithmetic1.equals("*")){
		   number_one=(number_one2 * number_two2)/100000000;
	    	 String s2 = String.valueOf(number_one);
	    	 tv.setText(s2);	 	
	}
	   else{
			 number_one=(number_one2 / number_two2);
	    	 String s3 = String.valueOf(number_one);
	    	 tv.setText(s3);	  
		}
   } 
}

    
            
      
              
                       
  
  
         
         
          
                                  
  
     
     
         
         
          
                                  
      

    
         
         
          
                                  
  
     
     
         
         
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