My code is giving me a NullPointerException and I've read through posts suggesting a clean-and-rebuild but that approach hasn't helped me so far.
My stack trace is as follows:
E/AndroidRuntime(553): FATAL EXCEPTION: main
E/AndroidRuntime(553): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.touchlogger/com.example.touchlogger.MainActivity}: java.lang.NullPointerException
E/AndroidRuntime(553): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
E/AndroidRuntime(553): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
E/AndroidRuntime(553): at android.app.ActivityThread.access$600(ActivityThread.java:123)
E/AndroidRuntime(553): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
E/AndroidRuntime(553): at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime(553): at android.os.Looper.loop(Looper.java:137)
E/AndroidRuntime(553): at android.app.ActivityThread.main(ActivityThread.java:4424)
E/AndroidRuntime(553): at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(553): at java.lang.reflect.Method.invoke(Method.java:511)
E/AndroidRuntime(553): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
E/AndroidRuntime(553): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
E/AndroidRuntime(553): at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime(553): Caused by: java.lang.NullPointerException
E/AndroidRuntime(553): at android.view.ViewGroup.addViewInner(ViewGroup.java:3336)
E/AndroidRuntime(553): at android.view.ViewGroup.addView(ViewGroup.java:3208)
E/AndroidRuntime(553): at android.view.ViewGroup.addView(ViewGroup.java:3188)
E/AndroidRuntime(553): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:270)
E/AndroidRuntime(553): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:260)
E/AndroidRuntime(553): at android.app.Activity.setContentView(Activity.java:1855)
E/AndroidRuntime(553): at com.example.touchlogger.MainActivity.onCreate(MainActivity.java:30)
E/AndroidRuntime(553): at android.app.Activity.performCreate(Activity.java:4465)
E/AndroidRuntime(553): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
E/AndroidRuntime(553): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
My XML file is as follows:
<com.example.touchlogger.DrawView
android:id="#+id/drawView1"
android:layout_width="wrap_content"
android:layout_height="357dp" />
<Button
android:id="#+id/button1"
android:layout_width="160dp"
android:layout_height="49dp"
android:layout_gravity="center|center_vertical"
android:layout_marginBottom="29dp"
android:text="End" />
</LinearLayout>
and the line which is causing the error is:
setContentView((LinearLayout)(findViewById(R.id.layout)));
I'm new to Android programming and even if the problem is quite simple, I'm afraid it just doesn't make any sense to me at all. I've spent over two days on this and I'm completely and utterly lost. My code was working up until I decided to include a button with the drawView. That's where it got a little screwed up. I've only been having problems ever since.
Any help would be hugely appreciated! Thanks in advance!
It won't work because your are calling the findViewById() method before the setContentView() one, so it will search for a view that it hasn't created yet. Use this instead :
setContentView(R.layout.my_xml_file);
It looks like you're trying to combine two incompatible steps. The first step is to tell the system which XML file to inflate and display, so you want to do what others have suggested:
setContentView(R.layout.xml_layout_filename);
Then, the second step to get the button or DrawView or other control, use something like
Button button = (Button)findViewById(R.id.button1);
DrawView drawView = (DrawView)findViewById(R.id.drawView1);
This should be:
setContentView(R.layout.your_xml_file_name_here);
Related
I'm trying to establish communication between Arduino UNO R3 and Galaxy SII on Android 4.1 cross usb. The code sample i am following i here: http://androidgurusolutions.blogspot.com/2012/07/arduino-adk-board-blink-led-with-your.html . Unfortunately, i am getting this message 'app has stopped' and here is LogCat error
LogCat:
E/AndroidRuntime(535): FATAL EXCEPTION: main
E/AndroidRuntime(535): java.lang.NoClassDefFoundError: com.android.future.usb.UsbManager
E/AndroidRuntime(535): at com.example.mypro.MainActivity.onCreate(MainActivity.java:123)
E/AndroidRuntime(535): at android.app.Activity.performCreate(Activity.java:4465)
E/AndroidRuntime(535): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
E/AndroidRuntime(535): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1919)
E/AndroidRuntime(535): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980)
E/AndroidRuntime(535):at android.app.ActivityThread.access$600(ActivityThread.java:122)
E/AndroidRuntime(535):at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146)
E/AndroidRuntime(535):at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime(535):at android.os.Looper.loop(Looper.java:137)
E/AndroidRuntime(535):at android.app.ActivityThread.main(ActivityThread.java:4340)
E/AndroidRuntime(535):at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(535):at java.lang.reflect.Method.invoke(Method.java:511)
E/AndroidRuntime(535):at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
E/AndroidRuntime(535):at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
E/AndroidRuntime(535):at dalvik.system.NativeStart.main(Native Method)
please can anybody help me. thanks in advance.....
I have a project that uses the GoogleMaps API, and the support library for Fragments. I have a working map in one activity already, so I know that the API and library are all set up right. I am trying to add a map in a fragment as part of a new activity.
The activity extends an android.support.v4.app.FragmentActivity, and the xml file contains:
<fragment
android:id="#+id/map"
android:layout_width="match_parent"
android:layout_height="250dp"
android:name="com.google.android.gms.maps.SupportMapFragment" />
But when I run I get the error:
01-20 11:58:31.535: ERROR/AndroidRuntime(5389): FATAL EXCEPTION: main
java.lang.NoClassDefFoundError: com.google.android.gms.R$styleable
at com.google.android.gms.maps.GoogleMapOptions.createFromAttributes(Unknown Source)
at com.google.android.gms.maps.SupportMapFragment.onInflate(Unknown Source)
at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:279)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:669)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:739)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:742)
at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:251)
at android.app.Activity.setContentView(Activity.java:1835)
at com.yedidyak.gpsalarm.AddAlarm.onCreate(AddAlarm.java:19)
at android.app.Activity.performCreate(Activity.java:4465)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
at android.app.ActivityThread.access$600(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
All the information I can find about this error is about not having the google-play-lib properly installed both as a jar and an imported module, but I have that done - and a working map in another activity.
Any ideas?
You have to reference google play services library instead of adding jar and map_attrs.xml (and other files, like strings.xml) to your project.
If you do, you also might have deleted res/values/map_attrs.xml by accident.
I'm seeing a weird exception in Android Support Library - the stack trace is below. Any ideas what could be causing this? I'm unable to reproduce the exception on any of my devices, but there seem to be quite a few visible in the Google Play DevConsole.
java.lang.NullPointerException
at android.support.v4.app.FragmentManagerImpl.makeInactive(FragmentManager.java:1133)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1044)
at android.support.v4.app.FragmentManagerImpl.removeFragment(FragmentManager.java:1171)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:582)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1416)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:420)
at android.os.Handler.handleCallback(Handler.java:608)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:156)
at android.app.ActivityThread.main(ActivityThread.java:5045)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
try check stack fragments in time rotate screen for example in onResume.
Please advice what the problem is with my code...
I am constantly getting this exception any suggestion would be really appreciated.
STACK_TRACE=java.lang.RuntimeException: Unable to start receiver com.platinumapps.platinumtasks.AlarmReceiver: java.lang.NullPointerException
at android.app.ActivityThread.handleReceiver(ActivityThread.java:1975)
at android.app.ActivityThread.access$1400(ActivityThread.java:122)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1074)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:132)
at android.app.ActivityThread.main(ActivityThread.java:4123)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:491)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.platinumapps.platinumtasks.AlarmReceiver.onReceive(AlarmReceiver.java:109)
at android.app.ActivityThread.handleReceiver(ActivityThread.java:1968)
... 10 more
java.lang.NullPointerException
at com.platinumapps.platinumtasks.AlarmReceiver.onReceive(AlarmReceiver.java:109)
at android.app.ActivityThread.handleReceiver(ActivityThread.java:1968)
at android.app.ActivityThread.access$1400(ActivityThread.java:122)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1074)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:132)
at android.app.ActivityThread.main(ActivityThread.java:4123)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:491)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
at dalvik.system.NativeStart.main(Native Method)
Its a nullpointer exception.
Means that something you are calling isn't initiated correctly, Or that you dont have access to that part(ei. havn't decalred activities in AndroidManifest. Or havn't included the rights jars etc.)
If you want better help, post the code you are working with.
Currently for my 2.x preference screens, in every PreferenceActivity I add the line setContentView(R.layout.activity_preferences); to have a custom layout in my activities.
The activity_preferences.xml layout file looks like this:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout style="#style/TitleBar">
<ImageButton style="#style/TitleBarAction"
android:src="#drawable/ic_title_home"
android:onClick="onHomeClick" />
<ImageView style="#style/TitleBarSeparator" />
<eu.vranckaert.worktime.utils.view.CustomTextView
style="#style/TitleBarText" android:text="#string/lbl_preferences_title"/>
</LinearLayout>
<ListView android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#android:id/list"/>
</LinearLayout>
For my 3.x and up application I am building the preferences according to the example over here: http://developer.android.com/reference/android/preference/PreferenceActivity.html.
In order to apply the same layout to my 3.x app, I tried was to add the setContentView(..) in the 3.x PreferenceActivity.
Result on phone: this works fine on the first activity, then when loading a fragment (with the real preferences in them) my style is not applied
Result on tablet: crash:
ERROR/AndroidRuntime(2208): FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{eu.vranckaert.worktime/eu.vranckaert.worktime.activities.preferences.PreferencesICSActivity}: java.lang.IllegalArgumentException: No view found for id 0x10202d4 for fragment TimeRegistrationsPreferencesFragment{4101ed38 #0 id=0x10202d4}
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
at android.app.ActivityThread.access$600(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalArgumentException: No view found for id 0x10202d4 for fragment TimeRegistrationsPreferencesFragment{4101ed38 #0 id=0x10202d4}
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:822)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1032)
at android.app.BackStackRecord.run(BackStackRecord.java:622)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1382)
at android.app.Activity.performStart(Activity.java:4474)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1929)
... 11 more
When I try to apply the layout file on my fragments using getActivity().setContentView(R.layout.activity_preferences); the result is:
for phone: the activity is still shown fine, when going into a category it crashes:
ERROR/AndroidRuntime(1320): FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{eu.vranckaert.worktime/eu.vranckaert.worktime.activities.preferences.PreferencesICSActivity}: java.lang.IllegalArgumentException: No view found for id 0x10202d4 for fragment DateTimePreferencesFragment{412a0d78 #0 id=0x10202d4}
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
at android.app.ActivityThread.access$600(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalArgumentException: No view found for id 0x10202d4 for fragment TimeRegistrationsPreferencesFragment{412a0d78 #0 id=0x10202d4}
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:822)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1032)
at android.app.BackStackRecord.run(BackStackRecord.java:622)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1382)
at android.app.Activity.performStart(Activity.java:4474)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1929)
... 11 more
for tablet: same crash as before...
How should I apply this layout file to my fragment activity...? Or should I create a new layout file?