Simple Calculator with Spinner – Android Code

This code is a simple code for Android application. It has two textboxes to receive two numbers (decimal), list of mathematical operations with +, –, * and /. Choose the operation, and hit the “Display result” button. You will see the answer to the at the bottom of the button. Have fun with Android.

 

The Manifest file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<EditText android:text="@+id/EditText01" 
	android:id="@+id/EditText01" 
	android:layout_width="fill_parent" 
	android:layout_height="wrap_content">
	</EditText>
<EditText android:text="@+id/EditText02" 
	android:id="@+id/EditText02" 
	android:layout_width="fill_parent" 
	android:layout_height="wrap_content">
	</EditText>
<Spinner android:id="@+id/Spinner01" 
	android:layout_width="fill_parent" 
	android:layout_height="wrap_content">
	</Spinner>
	
<Button android:text="@+id/Button01" 
	android:id="@+id/Button01" 
	android:layout_width="fill_parent" 
	android:layout_height="wrap_content">
	</Button>
<TextView android:text="@+id/TextView01" 
	android:id="@+id/TextView01" 
	android:layout_width="fill_parent" 
	android:layout_height="wrap_content">
	</TextView>
</LinearLayout>

The Code

 

package my.android.calc;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.AdapterView.OnItemSelectedListener;
public class Calc extends Activity implements OnItemSelectedListener{
    /** Called when the activity is first created. */
    EditText num1, num2;
	Button button01;
	TextView tv1;
	ImageView iv1;
	Spinner spinOps;
	String[] ops={"Choose operation","+","-","*","/"};
	String opselected;
	double a, b, c;
    private OnClickListener myClickListener = new OnClickListener()
    {
    	public void onClick(View v) {
    		a=Double.parseDouble(num1.getText().toString()); 
    		b=Double.parseDouble(num2.getText().toString()); 
    		if (opselected=="+"){c=a+b; tv1.setText(Double.toString(c));}
    		else if (opselected=="-"){c=a-b; tv1.setText(Double.toString(c));}
    		else if (opselected=="*"){c=a*b; tv1.setText(Double.toString(c));}
    		else if (opselected=="/"){c=a/b; tv1.setText(Double.toString(c));}
    		else {tv1.setText("Please select the operation");}
    		//tv1 = (TextView)findViewById(R.id.TextView01);
    		
    		
    	}
    };
        @Override
        public void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.main);
            
           tv1 = (TextView)findViewById(R.id.TextView01);
           //iv1= (ImageView)findViewById(R.id.);//try imageview
           
           button01 = (Button)findViewById(R.id.Button01);
           button01.setText("Display result");
           button01.setOnClickListener(myClickListener);
           
           num1 = (EditText)findViewById(R.id.EditText01);
           num1.setText("");
           num2 = (EditText)findViewById(R.id.EditText02);
           num2.setText("");
           
           //list of operations
           spinOps = (Spinner)findViewById(R.id.Spinner01);
           ArrayAdapter<String> adapter = new ArrayAdapter<String>(
             this, android.R.layout.simple_spinner_item, ops);
           adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
           spinOps.setAdapter(adapter);
           spinOps.setOnItemSelectedListener(this);
           
        }   
        public void onItemSelected (AdapterView<?> p,View v,int position,long id) {
        	opselected=ops[position];
        	tv1.setText("You have selected " + opselected);
        }
        public void onNothingSelected(AdapterView<?> p) { 
        	tv1.setText("Please select ops"); 
        }
}

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