java - Android DrawLayout Implementation -


ive been following post

android navigation drawer implemented activities

however application crashes before displays content. doesnt appear the oncreate menthod not triggering breakpoints

here mainactivity

package com.example.alex.menutest2;  import android.content.intent; import android.support.v4.widget.drawerlayout; import android.support.v7.app.actionbaractivity; import android.os.bundle; import android.view.menu; import android.view.menuitem; import android.view.view; import android.widget.adapterview; import android.widget.listview;    public class mainactivity extends actionbaractivity {      public listview mleftdrawerlist = (listview)findviewbyid(r.id.left_drawer);     public drawerlayout mdrawerlayout = (drawerlayout) findviewbyid(r.id.drawer_layout);       protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);         // other stuff initialize drawer layout, add list items         // ………         // ……….         // add listener drawer list view         mleftdrawerlist.setonitemclicklistener(new draweritemclicklistener());      }       private class draweritemclicklistener implements listview.onitemclicklistener {         @override         public void onitemclick(adapterview<?> adapterview, view view, int position, long id) {             switch (position) {                 case 0: {                     intent intent = new intent(mainactivity.this, documentactivity.class);                     startactivity(intent);                     break;                 }                 default:                     break;             }             mdrawerlayout.closedrawer(mleftdrawerlist);         }     } }

here xml layout

<android.support.v4.widget.drawerlayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_height="match_parent"     android:layout_width="match_parent"     android:id="@+id/drawer_layout">      <framelayout         android:id="@+id/activity_frame"/>     <listview     android:id="@+id/left_drawer"        android:entries="@array/menu_array"/> </android.support.v4.widget.drawerlayout>

here stack trace

06-14 19:14:26.127    8093-8093/com.example.alex.menutest2 e/androidruntime﹕ fatal exception: main     process: com.example.alex.menutest2, pid: 8093     java.lang.runtimeexception: unable instantiate activity componentinfo{com.example.alex.menutest2/com.example.alex.menutest2.mainactivity}: java.lang.nullpointerexception: attempt invoke virtual method 'android.view.view android.view.window.findviewbyid(int)' on null object reference             @ android.app.activitythread.performlaunchactivity(activitythread.java:2236)             @ android.app.activitythread.handlelaunchactivity(activitythread.java:2390)             @ 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:5257)             @ 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 'android.view.view android.view.window.findviewbyid(int)' on null object reference             @ android.app.activity.findviewbyid(activity.java:2072)             @ com.example.alex.menutest2.mainactivity.<init>(mainactivity.java:17)             @ java.lang.reflect.constructor.newinstance(native method)             @ java.lang.class.newinstance(class.java:1606)             @ android.app.instrumentation.newactivity(instrumentation.java:1066)             @ android.app.activitythread.performlaunchactivity(activitythread.java:2226)             at android.app.activitythread.handlelaunchactivity(activitythread.java:2390)             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:5257)             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)

i might wrong, think shouldn't initialize global parameters before oncreate() method called. you're trying initialize them findviewbyid() before contentview set.

based on error log, you've got nullpointer @ mdrawerlayout, makes me guess following line didn't find view:
public drawerlayout mdrawerlayout = (drawerlayout) findviewbyid(r.id.drawer_layout);


Comments

Post a Comment

Popular posts from this blog

c# - Validate object ID from GET to POST -

i have method allows user access comment have made on site. have post method lets them update comment. my normal solution send entire comment model through, let them update it, update on database when post back. involve sending commentid through in hiddenfor , can manipulated. how can verify commentid sent in get method same i'm getting in post , not able alter comment wish? how can verify commentid sent in method same i'm getting in post? basically have validate following things in post - user logged-in user. authenticated users post comments. commentid in post , should valid commentid , should present in database. userid associated logged-in user should same userid associated comment . comment should contain userid column, can check @ time of update. to make sure update happens comment has been sent in get - hold commentid in session , in post action compare commentid value in session .
Read more

node.js - Custom Model Validator SailsJS -

when using custom model validator checks record within model. return within spread doesn't seem end control flow. //post.js model /** * custom validator **/ types: { isuservalid: function(user_id) { var promise = require('bluebird'); promise.all([ user.findone({id: user_id}) ]) .spread(function(user) { console.log(user); if (user === null || user === undefined) { console.log('failed'); return false; }else{ console.log('passed'); return true; } }); } }, my response standard validation failed response. { "error": "e_validation", "status": 400, "summary": "1 attribute invalid", "model": "post", "invalidattributes": { "owner": [ { "rule": "isuservalid", ...
Read more

php - Find a regex to take part of Email -

i have following emails need extract part from: bestellnummer xxx: 1 von xxx, 1er pack ------------- anfang der nachricht ------------- foo bar baz foo bar baz // <<<<< need text here ------------- ende der nachricht ------------- ------------- anfang der nachricht ------------- foo bar baz foo bar baz ------------- ende der nachricht ------------- there 0 unlimited occurences of ------------- anfang der nachricht ------------- ------------- ende der nachricht ------------- and i'm able extract first part regex: $re = "/------------- .*? -------------.?(.*?).?------------- .*? -------------/s"; but, i'm quite new on learning regex, i'm pretty sure there must better regex extract part (foo bar baz foo bar baz) of text between ------------- anfang der nachricht ------------- ------------- ende der nachricht ------------- as can in different languages, i'm using .? to match between hyphens. i...
Read more