Fragment testing error: android.view.InflateException: Binary XML file line #16: Binary XML file line #16: Error inflating class <unknown>

问题

I am trying to test a fragment, following these instructions: https://developer.android.com/training/basics/fragments/testing

However I am getting the following crash when calling launchFragmentInContainer from my test.

Stacktrace:

android.view.InflateException: Binary XML file line #16: Binary XML file line #16: Error inflating class <unknown>

Caused by: android.view.InflateException: Binary XML file line #16: Error inflating class <unknown>
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
...
at android.view.LayoutInflater.$$robo$$android_view_LayoutInflater$createView(LayoutInflater.java:647)
...
at com.myapp.poll.PollHomeFragment.onCreateView(PollHomeFragment.kt:31)
...
Caused by: java.lang.UnsupportedOperationException: Failed to resolve attribute at index 13: TypedValue{t=0x2/d=0x7f0301b1 a=-1}
at android.content.res.TypedArray.getDrawableForDensity(TypedArray.java:946)
at android.content.res.TypedArray.getDrawable(TypedArray.java:930)
at android.view.View.__constructor__(View.java:5010)
at android.view.View.<init>(View.java)
at android.widget.TextView.<init>(TextView.java)
...
at com.myapp.poll.PollHomeFragment.onCreateView(PollHomeFragment.kt:31)

Here's the layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical"
tools:context=".poll.PollActivity">

<TextView
    android:id="@+id/tvEmail"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    tools:text="asdf@asdf.com" />

<TextView                      <!-- This is line 16 -->
    android:id="@+id/tvViewPoll"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/selectableItemBackground"
    android:gravity="center"
    android:minHeight="48dp"
    android:text="View Poll" />

<TextView
    android:id="@+id/tvCreatePoll"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/selectableItemBackground"
    android:gravity="center"
    android:minHeight="48dp"
    android:text="Create Poll" />

回答1:

OK, from an educated guess based on the stacktrace, I tried removing android:background="?attr/selectableItemBackground" and this resolves the issue.

It appears that ?attr/selectableItemBackground is perhaps not compatible with FragmentScenario or this is a framework bug.

I submitted a bug on the issue tracker: https://issuetracker.google.com/issues/144629519

Update from Google:

Status: Won't Fix (Intended Behavior) The default theme does not have an app defined attribute ?attr/selectableItemBackground (as Fragment has no dependency on AppCompat, MDC, etc)

It sounds like you should be passing the correct theme to FragmentScenario:

launchFragmentInContainer<PollHomeFragment>(themeResId = R.style.Theme_YourTheme)

来源：https://stackoverflow.com/questions/58903155/fragment-testing-error-android-view-inflateexception-binary-xml-file-line-16