Exemplo - Switch Button

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.CompoundButton;
import android.widget.EditText;
import android.widget.Switch;
import android.widget.ToggleButton;


public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final EditText dollar = (EditText) this.findViewById(R.id.editText);
        final EditText resultado = (EditText) this.findViewById(R.id.editText2);
        Button calcular = (Button) this.findViewById(R.id.button);
        calcular.setOnClickListener(new Button.OnClickListener(){
            public void onClick(View view){
                Switch toggle = (Switch) findViewById(R.id.switch1);
                toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                        if (isChecked) {
                            // The toggle is enabled
                            double dolar = Double.parseDouble(dollar.getEditableText().toString());
                            double resul = (dolar * 3.8)* 0.9;
                            resultado.setText(Double.toString(resul));
                        } else {
                            // The toggle is disabled
                            double dolar = Double.parseDouble(dollar.getEditableText().toString());
                            double resul = dolar * 3.8;
                            resultado.setText(Double.toString(resul));
                        }
                    }
                });

            }
        });

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;



    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}