android - my map app stops unexpectedly -

i'm new android. i'm working on app using google map. after several test, have same problem : app stops unexpectedly.

i present code.

the manifest:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.map_project"     android:versioncode="1"     android:versionname="1.0" >      <uses-sdk         android:minsdkversion="10"         android:targetsdkversion="21" />      <permission         android:name="com.map_project.permission.maps_receive"         android:protectionlevel="signature" />      <uses-feature         android:glesversion="0x00020000"         android:required="true" />      <uses-permission android:name="com.map_project.permission.maps_receive" />     <uses-permission android:name="android.permission.internet" />     <uses-permission android:name="android.permission.write_external_storage" />     <uses-permission android:name="com.google.android.providers.gsf.permission.read_gservices" />     <uses-permission android:name="android.permission.access_coarse_location" />     <uses-permission android:name="android.permission.access_fine_location" />      <application         android:allowbackup="true"         android:icon="@drawable/ic_launcher"         android:label="@string/app_name"         android:theme="@style/apptheme" >          <activity android:name=".mainactivity"             android:label="@string/app_name">              <intent-filter>                     <action android:name="android.intent.action.main" />                     <category android:name="android.intent.category.launcher" />                  </intent-filter>         </activity>          <meta-data             android:name="com.google.android.maps.v2.api_key"             android:value="mykeyxxx" />     </application>  </manifest> 

the map_activity.xml:

<?xml version="1.0" encoding="utf-8"?> <relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent" >      <fragment         android:id="@+id/map"         android:layout_width="match_parent"         android:layout_height="match_parent"         class="com.google.android.gms.maps.supportmapfragment" />  </relativelayout> 

and mainactivity:

 package com.map_project;  import android.os.bundle; import android.support.v4.app.fragmentactivity;  import com.google.android.gms.maps.cameraupdatefactory; import com.google.android.gms.maps.googlemap; import com.google.android.gms.maps.supportmapfragment; import com.google.android.gms.maps.model.latlng;  public class mainactivity extends fragmentactivity {       public void oncreate(bundle savedinstancestate){         super.oncreate(savedinstancestate);         setcontentview(r.layout.map_activity);          googlemap map = ((supportmapfragment) getsupportfragmentmanager().findfragmentbyid(r.id.map)).getmap();          latlng sydney = new latlng(-33.867, 151.206);          map.setmylocationenabled(true);         map.movecamera(cameraupdatefactory.newlatlngzoom(sydney, 13));      }   } 

when run application on phone, message: unfortunately, myapp has stopped. if can me, nice because begin despair.

firstly know testing on emulator or android mobile ?

if on emulator, ensure create google api based emulator. this emulator can used test google map , other google play service integration.

1) ok if use fragmentmanager instead of supportfragmentmanager , import same !

2)try declaring static final latlng sydney = new latlng(-33,151); before oncreate method

3)instead of extending fragmentactivity can extend activity 

your code looks good! can recheck these steps regarding api key:

4)make sure have created api key in googleapi console , activated google maps android api.(google console -> services -> on them)

use try-catch trace errors

try {         if (googlemap == null)        {             googlemap = ((mapfragment) getfragmentmanager().             findfragmentbyid(r.id.map)).getmap();        }         googlemap.setmaptype(googlemap.map_type_hybrid);         marker syd = googlemap.addmarker(new markeroptions().         position(sydney).title("its sydney"));     } catch (exception e)       {          e.printstacktrace();       }