Cody Cody - 4 months ago 6
Android Question

Android: Inflate Custom View inside Fragment

I have an application that uses a fragment view as part of its layout. Within this fragment, I want to instantiate a Paint Canvas where i can do custom drawing.

The problem is, my app crashes when I go to inflate the fragment with the error

android.view.InflateException: Binary XML file line #15: Binary XML file line #15: Error inflating class com.example.xxxxx.NeckCanvasOverlay


I'm not sure what's causing my Paint class not to inflate properly. I know there are special rules about how you use findViewById inside a fragment, but I thought I was adhering to them since i'm calling findViewByid on the fragment's view itself (called "v" in my code).

How can I fix this issue?

FragmentNeckDisplayMenu.java (Fragment Class)

public class FragmentNeckDisplayMenu extends Fragment {
private static View v;
private NeckCanvasOverlay neckHUD;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
v = inflater.inflate(R.layout.menu_fragment_neck_display,container,false); //ERROR HERE
NeckCanvasOverlay neckHUD = (NeckCanvasOverlay) v.findViewById(R.id.neckHUD); //paint test
...
return v;
}
}


NeckCanvasOverlay.java (Paint Class)

class NeckCanvasOverlay extends View {
private Paint mPainter;

public NeckCanvasOverlay(Context context) {
super(context);
initView();
}

private void initView(){ //Initializes canvas & paint objects here to save performance
mPainter = new Paint(Paint.ANTI_ALIAS_FLAG);
mPainter.setColor(Color.BLUE);
mPainter.setAlpha(128);
}

@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawCircle(180, 900, 200, mPainter);
}
}


menu_fragment_neck_display.xml (Fragment's Layout)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="@+id/canvas"
android:background="@drawable/image">

<LinearLayout
android:layout_width="148dp"
android:layout_height="0dp"
android:layout_gravity="center"
android:layout_weight="4">
!--Custom view for Canvas here -->
<com.example.xxxxx.NeckCanvasOverlay
android:id="@+id/neckHUD"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:background="@drawable/neck_for_menu"/>
</LinearLayout>

<Button
android:id="@+id/menuIcon"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_marginTop="64dp"
android:text="Menu"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_gravity="bottom"
android:layout_weight="0.5"/>
</LinearLayout>


Full Stack Trace (Edit: Included full trace)

08-06 21:47:24.894 26334-26334/com.example.xxxxx E/ACRA: ACRA caught a InflateException for com.example.xxxxx
android.view.InflateException: Binary XML file line #15: Binary XML file line #15: Error inflating class com.example.gu.NeckCanvasOverlay
at android.view.LayoutInflater.inflate(LayoutInflater.java:551)
at android.view.LayoutInflater.inflate(LayoutInflater.java:429)
at com.example.xxxxx.FragmentNeckDisplayMenu.onCreateView(FragmentNeckDisplayMenu.java:32)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613)
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1106)
at android.support.v4.view.ViewPager.populate(ViewPager.java:952)
at android.support.v4.view.ViewPager.setOffscreenPageLimit(ViewPager.java:733)
at com.example.xxxxx.PlayFrets.configMenu(PlayFrets.java:150)
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:125)
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:9)
at android.os.AsyncTask.finish(AsyncTask.java:651)
at android.os.AsyncTask.access$500(AsyncTask.java:180)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7229)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: android.view.InflateException: Binary XML file line #15: Error inflating class com.example.gu.NeckCanvasOverlay
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:788)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:716)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:847)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:810)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:855)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:810)
at android.view.LayoutInflater.inflate(LayoutInflater.java:527)
at android.view.LayoutInflater.inflate(LayoutInflater.java:429) 
at com.example.xxxxx.FragmentNeckDisplayMenu.onCreateView(FragmentNeckDisplayMenu.java:32) 
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248) 
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738) 
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613) 
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570) 
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141) 
at android.support.v4.view.ViewPager.populate(ViewPager.java:1106) 
at android.support.v4.view.ViewPager.populate(ViewPager.java:952) 
at android.support.v4.view.ViewPager.setOffscreenPageLimit(ViewPager.java:733) 
at com.example.xxxxx.PlayFrets.configMenu(PlayFrets.java:150) 
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:125) 
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:9) 
at android.os.AsyncTask.finish(AsyncTask.java:651) 
at android.os.AsyncTask.access$500(AsyncTask.java:180) 
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:158) 
at android.app.ActivityThread.main(ActivityThread.java:7229) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.gu.NeckCanvasOverlay" on path: DexPathList[[zip file "/data/app/com.example.xxxxx-2/base.apk"],nativeLibraryDirectories=[/data/app/com.example.xxxxx-2/lib/arm64, /vendor/lib64, /system/lib64]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
at android.view.LayoutInflater.createView(LayoutInflater.java:595)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:776)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:716) 
at android.view.LayoutInflater.rInflate(LayoutInflater.java:847) 
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:810) 
at android.view.LayoutInflater.rInflate(LayoutInflater.java:855) 
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:810) 
at android.view.LayoutInflater.inflate(LayoutInflater.java:527) 
at android.view.LayoutInflater.inflate(LayoutInflater.java:429) 
at com.example.xxxxx.FragmentNeckDisplayMenu.onCreateView(FragmentNeckDisplayMenu.java:32) 
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248) 
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738) 
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613) 
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570) 
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141) 
at android.support.v4.view.ViewPager.populate(ViewPager.java:1106) 
at android.support.v4.view.ViewPager.populate(ViewPager.java:952) 
at android.support.v4.view.ViewPager.setOffscreenPageLimit(ViewPager.java:733) 
at com.example.xxxxx.PlayFrets.configMenu(PlayFrets.java:150) 
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:125) 
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:9) 
at android.os.AsyncTask.finish(AsyncTask.java:651) 
at android.os.AsyncTask.access$500(AsyncTask.java:180) 
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:158) 
at android.app.ActivityThread.main(ActivityThread.java:7229) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 
Suppressed: java.lang.ClassNotFoundException: com.example.gu.NeckCanvasOverlay
at java.lang.Class.classForName(Native Method)
at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
... 33 more
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available
08-06 21:47:24.954 26334-27123/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.xxxxx, PID: 26334
android.view.InflateException: Binary XML file line #15: Binary XML file line #15: Error inflating class com.example.gu.NeckCanvasOverlay
at android.view.LayoutInflater.inflate(LayoutInflater.java:551)
at android.view.LayoutInflater.inflate(LayoutInflater.java:429)
at com.example.xxxxx.FragmentNeckDisplayMenu.onCreateView(FragmentNeckDisplayMenu.java:32)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613)
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1106)
at android.support.v4.view.ViewPager.populate(ViewPager.java:952)
at android.support.v4.view.ViewPager.setOffscreenPageLimit(ViewPager.java:733)
at com.example.xxxxx.PlayFrets.configMenu(PlayFrets.java:150)
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:125)
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:9)
at android.os.AsyncTask.finish(AsyncTask.java:651)
at android.os.AsyncTask.access$500(AsyncTask.java:180)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7229)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: android.view.InflateException: Binary XML file line #15: Error inflating class com.example.gu.NeckCanvasOverlay
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:788)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:716)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:847)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:810)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:855)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:810)
at android.view.LayoutInflater.inflate(LayoutInflater.java:527)
at android.view.LayoutInflater.inflate(LayoutInflater.java:429) 
at com.example.xxxxx.FragmentNeckDisplayMenu.onCreateView(FragmentNeckDisplayMenu.java:32) 
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248) 
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738) 
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613) 
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570) 
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141) 
at android.support.v4.view.ViewPager.populate(ViewPager.java:1106) 
at android.support.v4.view.ViewPager.populate(ViewPager.java:952) 
at android.support.v4.view.ViewPager.setOffscreenPageLimit(ViewPager.java:733) 
at com.example.xxxxx.PlayFrets.configMenu(PlayFrets.java:150) 
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:125) 
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:9) 
at android.os.AsyncTask.finish(AsyncTask.java:651) 
at android.os.AsyncTask.access$500(AsyncTask.java:180) 
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:158) 
at android.app.ActivityThread.main(ActivityThread.java:7229) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.gu.NeckCanvasOverlay" on path: DexPathList[[zip file "/data/app/com.example.xxxxx-2/base.apk"],nativeLibraryDirectories=[/data/app/com.example.xxxxx-2/lib/arm64, /vendor/lib64, /system/lib64]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
at android.view.LayoutInflater.createView(LayoutInflater.java:595)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:776)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:716) 
at android.view.LayoutInflater.rInflate(LayoutInflater.java:847) 
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:810) 
at android.view.LayoutInflater.rInflate(LayoutInflater.java:855) 
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:810) 
at android.view.LayoutInflater.inflate(LayoutInflater.java:527) 
at android.view.LayoutInflater.inflate(LayoutInflater.java:429) 
at com.example.xxxxx.FragmentNeckDisplayMenu.onCreateView(FragmentNeckDisplayMenu.java:32) 
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248) 
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738) 
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613) 
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570) 
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141) 
at android.support.v4.view.ViewPager.populate(ViewPager.java:1106) 
at android.support.v4.view.ViewPager.populate(ViewPager.java:952) 
at android.support.v4.view.ViewPager.setOffscreenPageLimit(ViewPager.java:733) 
at com.example.xxxxx.PlayFrets.configMenu(PlayFrets.java:150) 
at com.example.xxxxx.AsyncTask_NoteFileLoader.onPostExecute(AsyncTask_NoteFileLoader.java:125) 

Answer

The immediate problem is a ClassNotFoundException. When dealing with custom Views in a layout, a common cause for this is an incorrect class name in the layout XML, which seems to have been the issue here. Ensure that the XML tag has the correct, fully-qualified class name for the custom View class, which will be the class's package from the top of the file, prepended to the class name.

Additionally, Views inflated from your layout will be instantiated with a two-argument constructor that takes a Context and an AttributeSet. Your class definition needs to have at least that constructor to allow inflation, or you'll get a NoSuchMethodException. If you decide to use a style attribute in the XML, you'll need an additional constructor. It is also advisable to chain your constructors, if implementing others, if you're just extending View. For example:

public NeckCanvasOverlay(Context context) {
    this(context, null);
}

public NeckCanvasOverlay(Context context, AttributeSet attrs) {
    super(context, attrs);
    initView();
}