Android error : java.lang.NullPointerException: Attempt to invoke virtual method -
this question has answer here:
trying go next activity on button click.also data passed intent.i have error in android :
08-18 07:03:52.979 10587-10587/? e/androidruntime: fatal exception: main process: com.example.anjana.crmapp, pid: 10587 java.lang.runtimeexception: unable start activity componentinfo{com.example.anjana.crmapp/com.example.anjana.crmapp.mainactivity}: java.lang.nullpointerexception: attempt invoke virtual method 'android.view.view android.widget.button.findviewbyid(int)' on null object reference @ android.app.activitythread.performlaunchactivity(activitythread.java:2416) @ android.app.activitythread.handlelaunchactivity(activitythread.java:2476) @ android.app.activitythread.-wrap11(activitythread.java) @ android.app.activitythread$h.handlemessage(activitythread.java:1344) @ android.os.handler.dispatchmessage(handler.java:102) @ android.os.looper.loop(looper.java:148) @ android.app.activitythread.main(activitythread.java:5417) @ java.lang.reflect.method.invoke(native method) @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:726) @ com.android.internal.os.zygoteinit.main(zygoteinit.java:616) caused by: java.lang.nullpointerexception: attempt invoke virtual method 'android.view.view android.widget.button.findviewbyid(int)' on null object reference @ com.example.anjana.crmapp.mainactivity.oncreate(mainactivity.java:24) @ android.app.activity.performcreate(activity.java:6237) @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1107) @ android.app.activitythread.performlaunchactivity(activitythread.java:2369) @ android.app.activitythread.handlelaunchactivity(activitythread.java:2476) @ android.app.activitythread.-wrap11(activitythread.java) @ android.app.activitythread$h.handlemessage(activitythread.java:1344) @ android.os.handler.dispatchmessage(handler.java:102) @ android.os.looper.loop(looper.java:148) @ android.app.activitythread.main(activitythread.java:5417) @ java.lang.reflect.method.invoke(native method) @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:726) @ com.android.internal.os.zygoteinit.main(zygoteinit.java:616)
mainactivity.java :
package com.example.anjana.crmapp; import android.app.activity; import android.content.intent; import android.provider.contactscontract; import android.support.v7.app.appcompatactivity; import android.os.bundle; import android.view.view; import android.widget.button; import android.widget.imagebutton; public class mainactivity extends activity { button btnyes, btnno; imagebutton btngood,btnavg,btnpoor; int ans; @override protected void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.activity_main); btnyes = (button) btnyes.findviewbyid(r.id.btnyes); btnno = (button) btnno.findviewbyid(r.id.btnno); btngood=(imagebutton) btngood.findviewbyid(r.id.btngood); btnavg=(imagebutton) btnavg.findviewbyid(r.id.btnavg); btnpoor=(imagebutton) btnpoor.findviewbyid(r.id.btnpoor); btngood.setonclicklistener(new view.onclicklistener() { @override public void onclick(view v) { ans=1; } }); btnavg.setonclicklistener(new view.onclicklistener() { @override public void onclick(view v) { ans=2; } }); btnpoor.setonclicklistener(new view.onclicklistener() { @override public void onclick(view v) { ans=3; } }); btnyes.setonclicklistener(new view.onclicklistener() { @override public void onclick(view v) { //intent yesintent=new intent(); //yesintent.putextra("ans",ans); //startactivity(yesintent); } }); btnno.setonclicklistener(new view.onclicklistener() { @override public void onclick(view v) { intent nointent=new intent(getapplicationcontext(),contact.class); nointent.putextra("ans",ans); startactivity(nointent); } }); } } activity_main.xml :
<?xml version="1.0" encoding="utf-8"?> <relativelayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.anjana.crmapp.mainactivity" android:weightsum="1"> <textview android:id="@+id/textview" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_margintop="37dp" android:layout_weight="0.25" android:fontfamily="sans-serif" android:text="rate overall experience \n our service" android:textalignment="center" android:textcolor="@color/colorprimarydark" android:textsize="24sp" android:textstyle="bold" app:layout_constraintbottom_tobottomof="parent" app:layout_constraintleft_toleftof="parent" app:layout_constraintright_torightof="parent" app:layout_constrainttop_totopof="parent" android:layout_alignparenttop="true" android:layout_alignparentleft="true" android:layout_alignparentstart="true" /> <imagebutton android:id="@+id/btngood" android:layout_width="125dp" android:layout_height="100dp" android:layout_alignparentleft="true" android:layout_alignparentstart="true" android:layout_below="@+id/textview" android:layout_marginleft="17dp" android:layout_marginstart="17dp" android:layout_margintop="48dp" app:srccompat="@drawable/good" /> <imagebutton android:id="@+id/btnavg" android:layout_width="125dp" android:layout_height="100dp" android:layout_alignbottom="@+id/btngood" android:layout_centerhorizontal="true" app:srccompat="@drawable/average" /> <imagebutton android:id="@+id/btnpoor" android:layout_width="125dp" android:layout_height="100dp" android:layout_alignparentend="true" android:layout_alignparentright="true" android:layout_aligntop="@+id/btnavg" android:layout_marginend="20dp" android:layout_marginright="20dp" app:srccompat="@drawable/poor" /> <textview android:id="@+id/textview3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margintop="24dp" android:fontfamily="sans-serif" android:text="good" android:textcolor="@android:color/background_dark" android:textsize="18sp" android:textstyle="bold" android:layout_below="@+id/btngood" android:layout_alignleft="@+id/btngood" android:layout_alignstart="@+id/btngood" android:layout_marginleft="27dp" android:layout_marginstart="27dp" /> <textview android:id="@+id/textview4" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignbaseline="@+id/textview3" android:layout_alignbottom="@+id/textview3" android:layout_centerhorizontal="true" android:fontfamily="sans-serif" android:text="average" android:textcolor="@android:color/background_dark" android:textsize="18sp" android:textstyle="bold" /> <textview android:id="@+id/textview5" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignparentend="true" android:layout_alignparentright="true" android:layout_aligntop="@+id/textview4" android:layout_marginend="32dp" android:layout_marginright="32dp" android:fontfamily="sans-serif" android:text="poor" android:textcolor="@android:color/background_dark" android:textsize="18sp" android:textstyle="bold" /> <textview android:id="@+id/textview7" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="take part in our feedback survey.." android:textalignment="center" android:textcolor="@color/colorprimarydark" android:textsize="22dp" android:textstyle="bold" android:layout_alignbottom="@+id/textview5" android:layout_alignleft="@+id/textview3" android:layout_alignstart="@+id/textview3" /> <button android:id="@+id/btnyes" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="yes" android:layout_marginbottom="76dp" android:layout_alignparentbottom="true" android:layout_torightof="@+id/btnavg" android:layout_toendof="@+id/btnavg" /> <button android:id="@+id/btnno" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_aligntop="@+id/btnyes" android:layout_toendof="@+id/textview3" android:layout_torightof="@+id/textview3" android:text="no,thanks" /> </relativelayout> i don't know why error occurs!please me...
Comments
Post a Comment