android - Can't get the editText integer value right -

i'm new programming don't know how fix or why it's happening.

i'm making app , in main2activity it's suppose user insert value in edittext , then, after user presses button, value turn integer , used in mathematical operation.

the thing is, when try out, when press button in mainactivity take me main2activity, app crashes.

i narrowed problem coding have in button main2activity don't know what's wrong.

this main2activity code. can me? thanks.

package com.example.cabr.teste;  import android.content.intent; 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;  public class main2activity extends appcompatactivity {      public double valorhorasponta = 0;     public double valorhorascheias = 0;     public double valorhorasvazio = 0;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main2);          textview textview9 = (textview) findviewbyid(r.id.textview9);         textview textview10 = (textview) findviewbyid(r.id.textview10);         textview textview12 = (textview) findviewbyid(r.id.textview12);         textview textview14 = (textview) findviewbyid(r.id.textview14);         final textview textview11 = (textview) findviewbyid(r.id.textview11);         final textview textview13 = (textview) findviewbyid(r.id.textview13);         final textview textview15 = (textview) findviewbyid(r.id.textview15);         final textview textview17 = (textview) findviewbyid(r.id.textview17);          final edittext edittext1 = (edittext) findviewbyid(r.id.edittext1);         final edittext edittext2 = (edittext) findviewbyid(r.id.edittext2);         final edittext edittext3 = (edittext) findviewbyid(r.id.edittext3);         final edittext edittext4 = (edittext) findviewbyid(r.id.edittext4);          button button = (button) findviewbyid(r.id.button);          intent = getintent();         string valorpot1 = i.getstringextra("valorpot1");         string valorpot12 = i.getstringextra("valorpot12");          textview9.settext(valorpot1);           if (valorpot12.equals("tarifas de médias utilizações")){             valorhorasponta = 0.3128;             textview10.settext(string.valueof(valorhorasponta));              valorhorascheias = 0.1555;             textview12.settext(string.valueof(valorhorascheias));              valorhorasvazio = 0.0862;             textview14.settext(string.valueof(valorhorasvazio));         }         if (valorpot12.equals("tarifas de longas utilizações")){             valorhorasponta = 0.2318;             textview10.settext(string.valueof(valorhorasponta));              valorhorascheias = 0.1341;             textview12.settext(string.valueof(valorhorascheias));              valorhorasvazio = 0.08;             textview14.settext(string.valueof(valorhorasvazio));         }          button.setonclicklistener(new view.onclicklistener() {             @override             public void onclick(view v) {                  string valorquantponta1 = edittext1.gettext().tostring();                 int valorquantponta = integer.parseint(valorquantponta1);                  string valorquantcheias1 = edittext2.gettext().tostring();                 int valorquantcheias = integer.parseint(valorquantcheias1);                  string valorquantvazio1 = edittext3.gettext().tostring();                 int valorquantvazio = integer.parseint(valorquantvazio1);                  string valorquantpot1 = edittext4.gettext().tostring();                 int valorquantpot = integer.parseint(valorquantpot1);                  double valortotponta = valorhorasponta * valorquantponta;                 double valortotcheias = valorhorascheias * valorquantcheias;                 double valortotvazio = valorquantvazio * valorhorasvazio;                  textview11.settext(string.valueof(valortotponta));                 textview13.settext(string.valueof(valortotcheias));                 textview15.settext(string.valueof(valortotvazio));             }         });      } } 

you can take value edittext in way

edittext edittext=(edittext)findviewbyid(r.id.edittext);

string string=edittext.gettext().tostring;

int int_value_from_edittext=integer.parseint(string);