android - Simple intent crashes app -


new android.

i'm trying create simple intent in onclicklistener open new page. however, app crashing when click button. i'm not sure wrong.

here's listener

 buttoncheat.setonclicklistener(new view.onclicklistener() {         @override         public void onclick(view v) {            intent cheatview = new intent(getapplicationcontext(),cheatactivity.class);             startactivity(cheatview);         }

here's have declared activities in manifest file

<application     android:allowbackup="true"     android:icon="@drawable/ic_launcher"     android:label="@string/app_name"     android:theme="@style/apptheme" >     <activity       android:name=".quizactivity"       android:label="@string/app_name" >       <intent-filter>         <action android:name="android.intent.action.main" />          <category android:name="android.intent.category.launcher" />       </intent-filter>     </activity>     <activity       android:name=".cheatactivity"       android:label="@string/app_name" />   </application>

here relevant logs

10-03 01:51:23.770    2630-2630/? d/cheatactivity﹕ oncreate() called 10-03 01:51:23.777    2630-2630/? d/androidruntime﹕ shutting down vm 10-03 01:51:23.777    2630-2630/? e/androidruntime﹕ fatal exception: main     process: itp341.exercises.week6.geoquiz, pid: 2630     java.lang.runtimeexception: unable start activity componentinfo{itp341.exercises.week6.geoquiz/itp341.exercises.week6.geoquiz.cheatactivity}: java.lang.nullpointerexception: attempt invoke virtual method 'java.lang.string android.content.componentname.tostring()' on null object reference             @ android.app.activitythread.performlaunchactivity(activitythread.java:2325)             @ android.app.activitythread.handlelaunchactivity(activitythread.java:2387)             @ android.app.activitythread.access$800(activitythread.java:151)             @ android.app.activitythread$h.handlemessage(activitythread.java:1303)             @ android.os.handler.dispatchmessage(handler.java:102)             @ android.os.looper.loop(looper.java:135)             @ android.app.activitythread.main(activitythread.java:5254)             @ java.lang.reflect.method.invoke(native method)             @ java.lang.reflect.method.invoke(method.java:372)             @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:903)             @ com.android.internal.os.zygoteinit.main(zygoteinit.java:698)      caused by: java.lang.nullpointerexception: attempt invoke virtual method 'java.lang.string android.content.componentname.tostring()' on null object reference             @ itp341.exercises.week6.geoquiz.cheatactivity.oncreate(cheatactivity.java:49)             @ android.app.activity.performcreate(activity.java:5990)             @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1106)             @ android.app.activitythread.performlaunchactivity(activitythread.java:2278)             at android.app.activitythread.handlelaunchactivity(activitythread.java:2387)             at android.app.activitythread.access$800(activitythread.java:151)             at android.app.activitythread$h.handlemessage(activitythread.java:1303)             at android.os.handler.dispatchmessage(handler.java:102)             at android.os.looper.loop(looper.java:135)             at android.app.activitythread.main(activitythread.java:5254)             at java.lang.reflect.method.invoke(native method)             at java.lang.reflect.method.invoke(method.java:372)             at com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:903)             at com.android.internal.os.zygoteinit.main(zygoteinit.java:698)

from cheatactivity 

public class cheatactivity extends activity {      private static final string tag = "cheatactivity";       // view references     textview textanswer;     button buttonshowanswer;      // instance variables     boolean answeristrue;       @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         log.d(tag, "oncreate() called");         setcontentview(r.layout.activity_cheat);         log.d(tag, getcallingactivity().tostring()); =         //find views         textanswer = (textview) findviewbyid(r.id.text_answer);         buttonshowanswer = (button) findviewbyid(r.id.button_show_answer);     }   } 

 intent cheatview = new intent(getapplicationcontext(),cheatactivity.class);

this why exception existed,try use replace it,

intent cheatview = new intent(quizactivity.this,cheatactivity.class);

beacause application context can't start activity.


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