android - setOnClickListener error - cannot resolve symbol -

i want create button which, when clicked, show intent.

this code:

   <button     android:text="bine ati venit!"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:id="@+id/button1"     android:background="#479fc7"     android:textsize="40dp"     android:textcolor="@color/colorprimarydark"     android:textstyle="normal|bold|italic"     android:textallcaps="false"     android:fontfamily="casual"     android:onclick="next_page"/> 

and .java class:

    protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_welcome); }  button button = (button) findviewbyid(r.id.button1);  button.setonclicklistener( new view.onclicklistener() {     public void onclick (view v){     next_page(v); } });  public void next_page(view v) {     intent intent = new intent(this, mapsactivity.class);     startactivity(intent); } 

i errors: "cannot resolve symbol 'setonclicklistener'", "variable onclick never used", "; expected"....

you either declare onclick attribute method name in xml or programaticaly set in oncreate method.

protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_welcome);      button button = (button) findviewbyid(r.id.button1);      button.setonclicklistener( new view.onclicklistener()     {         public void onclick (view v){            next_page(v);         }     }); }  public void next_page(view v) {     intent intent = new intent(this, mapsactivity.class);     startactivity(intent); }