java - Accessing a variable from one class that is located in another class -

iv been stuck on bug, in android app, 3 weeks now. killing me... :(. can please fix code me (its small error), , can learn it. basically, have mainactivity class holds variable "dblcountvalue". want access variable in withdraw class. here code:

class: mainactivity

package com.mycash.borgjake.mycash;  import android.content.intent; import android.support.v7.app.appcompatactivity; import android.os.bundle;  import android.widget.button; import android.widget.textview;  import android.view.view;  import com.google.android.gms.ads.adlistener; import com.google.android.gms.ads.adrequest; import com.google.android.gms.ads.adview; import com.google.android.gms.ads.interstitialad;  import static com.mycash.borgjake.mycash.r.styleable.view;  public class mainactivity extends appcompatactivity {  private interstitialad minterstitial;   button btnclick; button btnwithdraw;  textview txtbalance;  @override protected void oncreate(bundle savedinstancestate) {      super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);      adview adview = (adview)findviewbyid(r.id.adview);     adrequest adrequest = new adrequest.builder()             .addtestdevice(adrequest.device_id_emulator)             .build();     adview.loadad(adrequest);      btnclick = (button) findviewbyid(r.id.button);      txtbalance = (textview) findviewbyid(r.id.textview);      btnclick.setonclicklistener(new view.onclicklistener() {          @override         public void onclick(view v){                 string countvalue = txtbalance.gettext().tostring();                 int dblcountvalue = integer.parseint(countvalue);                  if (minterstitial.isloaded()) {                     minterstitial.show();                 }                  //minterstitial.loadad(request);                  dblcountvalue++;                 txtbalance.settext(string.valueof(dblcountvalue));          }     });      minterstitial = new interstitialad(this);     minterstitial.setadunitid("...");     adrequest request = new adrequest.builder()             .addtestdevice(adrequest.device_id_emulator)             .build();     minterstitial.loadad(request);  }  public void onbuttonclick(view v) {     if(v.getid() == r.id.button2) {         intent = new intent(mainactivity.this, withdraw.class);         startactivity(i);     }   } } 

class: withdraw

package com.mycash.borgjake.mycash;  import android.app.activity; import android.app.alertdialog; import android.os.bundle; import android.view.view;  import com.google.android.gms.ads.adrequest; import com.google.android.gms.ads.adview;  public class withdraw extends activity {  mainactivity mainactivityobject = new mainactivity();  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.withdraw);      adview adview = (adview) findviewbyid(r.id.adview2);     adrequest adrequest = new adrequest.builder()             .addtestdevice(adrequest.device_id_emulator)             .build();     adview.loadad(adrequest); }  public void showalert(view view) {     alertdialog.builder myalert = new alertdialog.builder(this);      string messagewithdraw;     string awithdraw;     string dwithdraw;     awithdraw = "congradulations! payment being processed";     dwithdraw = "sorry! please try again when reach 100 points ($10)";        dblcountvalue = mainactivityobject.dblcountvalue;      // <-- error      if (dblcountvalue > 100) {                           // <-- error         myalert.setmessage(awithdraw)                                    .create();                                      myalert.show();                                    } else {                                                  myalert.setmessage(dwithdraw)                                .create();                                  myalert.show();                                }                                                } } 

thanks lot in advance :)

to send variable 1 activity other activity should use intent object.in case have create intent object in mainactivity , intent object can send data withdraw class.

you should write code in mainactivity.

public void onclick(view v){                 string countvalue = txtbalance.gettext().tostring();                 int dblcountvalue = integer.parseint(countvalue);                  if (minterstitial.isloaded()) {                     minterstitial.show();                 }                  //minterstitial.loadad(request);                  dblcountvalue++;                 txtbalance.settext(string.valueof(dblcountvalue));          intent intent = new intent(mainactivity.this, withdraw.class);         intent.putextra( "key" , dblcountvalue);                startactivity(intent);          }     }); 

now section of code take place in withdraw class in side oncreate method .here extract dblcountvalue intet object using key .

in withdraw class replace dblcountvalue = mainactivityobject.dblcountvalue;

with following code section

bundle bundle = getintent().getextras(); int dblcountvalue =bundle.getint("key",0);