Calcular grados fahrenheit -Android

package com.inforhomex.auditor; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends AppCompatActivity { private EditText editText1; private TextView textView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Toast.makeText(this,"Creando App",Toast.LENGTH_SHORT).show(); editText1 = (EditText) findViewById(R.id.editText1); textView = (TextView) findViewById(R.id.textView); } public void celsius(View view){ String valor1 = editText1.getText().toString(); double calculo = (Double.parseDouble(valor1) * 1.8) + 32; String resultado = String.valueOf(calculo); Toast.makeText(this,"Fahrenheit = "+resultado,Toast.LENGTH_SHORT).show(); textView.setText(resultado); editText1.setText(""); } @Override protected void onStart(){ super.onStart(); Toast.makeText(this,"Iniciando App",Toast.LENGTH_SHORT).show(); } @Override protected void onResume(){ super.onResume(); Toast.makeText(this,"Resumiendo App",Toast.LENGTH_SHORT).show(); } @Override protected void onPause(){ super.onPause(); Toast.makeText(this,"Pausando App",Toast.LENGTH_SHORT).show(); } @Override protected void onStop(){ super.onStop(); Toast.makeText(this,"Deteniendo App",Toast.LENGTH_SHORT).show(); } @Override protected void onDestroy(){ super.onDestroy(); Toast.makeText(this,"Destruyendo App",Toast.LENGTH_SHORT).show(); } }