Facing calculator app error in android -

friends searched lot didnt answer of question. trying make android calculator. simple 1 , single module of bigger app...

in firstly need users enter 1st , 2nd sunber , select if add, sub, mul, divide or mod..then there textview in result displayed.

this code using :

java code:

package com.droidacid.apticalc;  import android.app.activity; import android.os.bundle; import android.view.view; import android.widget.button; import android.widget.edittext; import android.widget.textview;  public class numsys extends activity{   edittext etnumber1; edittext etnumber2;  button badd; button bsub; button bmul; button bdiv; button bmod;  @override protected void oncreate(bundle savedinstancestate) {     // todo auto-generated method stub     super.oncreate(savedinstancestate);     setcontentview(r.layout.numsys);      etnumber1 = (edittext) findviewbyid(r.id.number1);     etnumber2 = (edittext) findviewbyid(r.id.number2);        string number1 = etnumber1.gettext().tostring();     string number2 = etnumber2.gettext().tostring();      final double number1d = double.parsedouble(number1);     final double number2d = double.parsedouble(number2);  badd.setonclicklistener(new view.onclicklistener() {      @override     public void onclick(view v) {         // todo auto-generated method stub      double resultd = number1d + number2d;     string result = "result :"+resultd;     textview tvresult = (textview) findviewbyid(r.id.tvresult);     tvresult.settext(result);     } });  bsub.setonclicklistener(new view.onclicklistener() {      @override     public void onclick(view v) {         // todo auto-generated method stub      double resultd = number1d - number2d;     string result = "result :"+resultd;     textview tvresult = (textview) findviewbyid(r.id.tvresult);     tvresult.settext(result);     } });  bmul.setonclicklistener(new view.onclicklistener() {  @override public void onclick(view v) {     // todo auto-generated method stub  double resultd = number1d * number2d; string result = "result :"+resultd; textview tvresult = (textview) findviewbyid(r.id.tvresult); tvresult.settext(result); } });  bdiv.setonclicklistener(new view.onclicklistener() {  @override public void onclick(view v) {     // todo auto-generated method stub  double resultd = number1d / number2d; string result = "result :"+resultd; textview tvresult = (textview) findviewbyid(r.id.tvresult); tvresult.settext(result); } });  bmod.setonclicklistener(new view.onclicklistener() {  @override public void onclick(view v) {     // todo auto-generated method stub  double resultd = number1d % number2d; string result = "result :"+resultd; textview tvresult = (textview) findviewbyid(r.id.tvresult); tvresult.settext(result); } });    }   } 

this logcat error :

05-04 10:24:18.098: e/androidruntime(1321): java.lang.runtimeexception: unable start activity componentinfo{com.droidacid.apticalc/com.droidacid.apticalc.numsys}: java.lang.numberformatexception:  

please dont rate post negative. trying learn , trying solve issue since last more 24 hours. tried posted on stack overflow.

thanks

this might problem:

    string number1 = etnumber1.gettext().tostring();     string number2 = etnumber2.gettext().tostring();      final double number1d = double.parsedouble(number1);     final double number2d = double.parsedouble(number2); 

you're trying parse an, @ point, empty edittext double value. either that, or have default text in edittext you're trying parse.

this (probably) causes numberformatexception.