findViewById returning null in extended LinearLayout

Question

I have a custom linear layout that looks like this:

public class CheckedLinearLayout extends LinearLayout implements Checkable {
    private RadioButton mRadio;

    public CheckedLinearLayout(Context context, AttributeSet attributeSet){
        super(context, attributeSet);
        LayoutInflater inflater = LayoutInflater.from(context);
        inflater.inflate(R.layout.list_item, null);
        this.mRadio = (RadioButton)findViewById(R.id.radio_button);
    }
}

However the findViewById is always returning null.

The xml:

<?xml version="1.0" encoding="utf-8"?>
<derongan.upper.CheckedLinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="wrap_content">

<TextView
    android:id="@+id/count_type"
    android:layout_width="0dp"
    android:layout_weight="1"
    android:layout_height="match_parent" />

<EditText
    android:id="@+id/edit_text"
    android:layout_width="0dp"
    android:layout_height="match_parent"
    android:layout_weight="1"
    android:hint="New Counter"
    android:visibility="gone"/>

<RadioButton
    android:id="@+id/radio_button"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"/>
</derongan.upper.CheckedLinearLayout>

Why is the findViewById always returning null, and how can I properly call it? Am I inflating the view wrong?

Edit:

When I add

View view = inflater.inflate(...)

I get a new error (that seems to have to do with memory problems?)

09-19 23:53:22.760     982-1015/? E/SurfaceFlinger﹕ ro.sf.lcd_density must 

be defined as a build property
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115] JNI ERROR (app bug): local reference table overflow (max=512)
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115] local reference table dump:
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]   Last 10 entries (of 512):
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       511: 0x12c918b0 derongan.upper.UpperWidgetConfigure
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       510: 0x12d735e0 java.lang.String "derongan.upper.C... (34 chars)
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       509: 0x12c918b0 derongan.upper.UpperWidgetConfigure
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       508: 0x12e74800 derongan.upper.CheckedLinearLayout
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       507: 0x12e74400 derongan.upper.CheckedLinearLayout
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       506: 0x12e74000 derongan.upper.CheckedLinearLayout
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       505: 0x12e73c00 derongan.upper.CheckedLinearLayout
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       504: 0x12e73800 derongan.upper.CheckedLinearLayout
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       503: 0x12e73400 derongan.upper.CheckedLinearLayout
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       502: 0x12e72c00 derongan.upper.CheckedLinearLayout
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]   Summary:
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]       503 of derongan.upper.CheckedLinearLayout (503 unique instances)
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]         2 of derongan.upper.UpperWidgetConfigure (1 unique instances)
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]         2 of java.lang.Class (2 unique instances)
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]         1 of java.lang.String[] (3 elements)
09-19 23:53:22.856  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]         4 of java.lang.String (4 unique instances)
09-19 23:53:22.857  11757-11757/derongan.upper A/art﹕ art/runtime/indirect_reference_table.cc:115]
09-19 23:53:23.520  11757-11757/derongan.upper A/art﹕ art/runtime/barrier.cc:90] Check failed: count_ == 0 (count_=-1, 0=0) Attempted to destroy barrier with non zero count
09-19 23:53:23.520  11757-11757/derongan.upper A/art﹕ art/runtime/runtime.cc:366] Runtime aborting --- recursively, so no thread-specific detail!
09-19 23:53:23.520  11757-11757/derongan.upper A/art﹕ art/runtime/runtime.cc:366]
09-19 23:53:23.520  11757-11757/derongan.upper A/libc﹕ Fatal signal 6 (SIGABRT), code -6 in tid 11757 (derongan.upper)
09-19 23:53:23.658    4490-4490/? A/DEBUG﹕ *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
09-19 23:53:23.658    4490-4490/? A/DEBUG﹕ Build fingerprint: 'generic_x86/sdk_google_phone_x86/generic_x86:6.0/MRA44C/2166767:eng/test-keys'
09-19 23:53:23.658    4490-4490/? A/DEBUG﹕ Revision: '0'
09-19 23:53:23.658    4490-4490/? A/DEBUG﹕ ABI: 'x86'
09-19 23:53:23.658    4490-4490/? A/DEBUG﹕ pid: 11757, tid: 11757, name: derongan.upper  >>> derongan.upper <<<
09-19 23:53:23.658    4490-4490/? A/DEBUG﹕ signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr --------
09-19 23:53:23.661    4490-4490/? A/DEBUG﹕ Abort message: 'art/runtime/indirect_reference_table.cc:115] JNI ERROR (app bug): local reference table overflow (max=512)'
09-19 23:53:23.661    4490-4490/? A/DEBUG﹕ eax 00000000  ebx 00002ded  ecx 00002ded  edx 00000006
09-19 23:53:23.661    4490-4490/? A/DEBUG﹕ esi b77b8c50  edi 00000002
09-19 23:53:23.661    4490-4490/? A/DEBUG﹕ xcs 00000073  xds 0000007b  xes 0000007b  xfs 00000007  xss 0000007b
09-19 23:53:23.661    4490-4490/? A/DEBUG﹕ eip b73815d6  ebp 00002ded  esp bfe3adb0  flags 00200206
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ backtrace:
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #00 pc 000845d6  /system/lib/libc.so (tgkill+22)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #01 pc 00081618  /system/lib/libc.so (pthread_kill+70)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #02 pc 00027205  /system/lib/libc.so (raise+36)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #03 pc 000209e4  /system/lib/libc.so (abort+80)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #04 pc 0051753b  /system/lib/libart.so (art::Runtime::Abort()+377)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #05 pc 0014d9f3  /system/lib/libart.so (art::LogMessage::~LogMessage()+1343)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #06 pc 00147f36  /system/lib/libart.so (art::Barrier::~Barrier()+966)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #07 pc 0056027f  /system/lib/libart.so (art::ThreadList::Dump(std::__1::basic_ostream<char, std::__1::char_traits<char> >&)+271)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #08 pc 005176b8  /system/lib/libart.so (art::Runtime::Abort()+758)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #09 pc 0014d9f3  /system/lib/libart.so (art::LogMessage::~LogMessage()+1343)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #10 pc 002e70ac  /system/lib/libart.so (art::IndirectReferenceTable::Add(unsigned int, art::mirror::Object*)+860)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #11 pc 00664ec1  /system/lib/libart.so (art::RememberForGcArgumentVisitor::Visit()+89)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #12 pc 0066523b  /system/lib/libart.so (art::QuickArgumentVisitor::VisitArguments() (.constprop.257)+223)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #13 pc 00669ed4  /system/lib/libart.so (artQuickResolutionTrampoline+1060)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #14 pc 0013d7fd  /system/lib/libart.so (art_quick_resolution_trampoline+77)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #15 pc 005cbc10  /data/app/derongan.upper-1/oat/x86/base.odex (android.view.View android.support.v4.app.FragmentActivity.onCreateView(java.lang.String, android.content.Context, android.util.AttributeSet)+84)
09-19 23:53:23.663    4490-4490/? A/DEBUG﹕ #16 pc 7416d2b7  /data/dalvik-cache/x86/system@framework@boot.oat
09-19 23:53:23.830    4490-4490/? A/DEBUG﹕ Tombstone written to: /data/tombstones/tombstone_09
09-19 23:53:23.830    4490-4490/? E/DEBUG﹕ AM write failed: Broken pipe
09-19 23:53:23.856    1291-1331/system_process E/InputDispatcher﹕ channel 'd69290f derongan.upper/derongan.upper.UpperWidgetConfigure (server)' ~ Channel is unrecoverably broken and will be disposed!
09-19 23:53:24.095    2203-2203/com.android.launcher3 E/Launcher﹕ Error: appWidgetId (EXTRA_APPWIDGET_ID) was not returned from the widget configuration activity.

Answer 1

There are two things you must do here.

First, in your code, replace:

inflater.inflate(R.layout.list_item, null);

with:

inflater.inflate(R.layout.list_item, this);

This way you will tell the inflater to attach the inflated view to your hierarchy. Giving a null parameter will leave the inflated view floating without a parent.

Secondly, In your xml tag, replace:

derongan.upper.CheckedLinearLayout

with a simple

LinearLayout

By doing this you will avoid recursively recreating your view (calling inflate on your custom view layout will unfortunately call it's xml constructor, and having an inflate call in the same constructor will give you that overflow error). Just use a LinearLayout in the xml or provide two types of constructors for your view.

Answer 2

add following line in your xml custom linear layout

android:id="@+id/linearLayout1"

like this

<?xml version="1.0" encoding="utf-8"?>
<derongan.upper.CheckedLinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/linearLayout1"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="wrap_content">

<TextView
    android:id="@+id/count_type"
    android:layout_width="0dp"
    android:layout_weight="1"
    android:layout_height="match_parent" />

<EditText
    android:id="@+id/edit_text"
    android:layout_width="0dp"
    android:layout_height="match_parent"
    android:layout_weight="1"
    android:hint="New Counter"
    android:visibility="gone"/>

<RadioButton
    android:id="@+id/radio_button"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"/>
</derongan.upper.CheckedLinearLayout>

thats's it

Answer 3

You're inflating the view but not attaching it to your CheckedLinearLayout.

Simply replace inflater.inflate(R.layout.list_item, null); with inflater.inflate(R.layout.list_item, this);, which inflates the XML into the view.

Answer 4

try the following code it will help you if radiobutton in same list_item layout

  LayoutInflater inflater = LayoutInflater.from(context);
           View customvw= inflater.inflate(R.layout.list_item, null);
            this.mRadio = (RadioButton)customvw.findViewById(R.id.radio_button);