InflateException with FloatingActionButton from Official Design Library

问题

I am getting a bug using the official FloatingActionButton from Google\'s support design library.

Here is my LogCat.

android.view.InflateException: Binary XML file line #34: Error inflating class android.support.design.widget.FloatingActionButton
at android.view.LayoutInflater.createView(LayoutInflater.java:633)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:743)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
at de.robv.android.xposed.XposedBridge.invokeOriginalMethodNative(Native Method)
at de.robv.android.xposed.XposedBridge.handleHookedMethod(XposedBridge.java:655)
at android.view.LayoutInflater.inflate(Unknown Source)
at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
at ---.---.com.---.SubCategoryFragment.onCreateView(SubCategoryFragment.java:47)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1789)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:955)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1138)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:740)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1501)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:458)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:117)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.newInstance(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:288)
at android.view.LayoutInflater.createView(LayoutInflater.java:607)
... 24 more
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method \'android.graphics.drawable.Drawable android.graphics.drawable.Drawable$ConstantState.newDrawable()\' on a null object reference
at android.graphics.drawable.LayerDrawable$ChildDrawable.<init>(LayerDrawable.java:968)
at android.graphics.drawable.LayerDrawable$LayerState.<init>(LayerDrawable.java:1014)
at android.graphics.drawable.RippleDrawable$RippleState.<init>(RippleDrawable.java:910)
at android.graphics.drawable.RippleDrawable.createConstantState(RippleDrawable.java:901)
at android.graphics.drawable.RippleDrawable.createConstantState(RippleDrawable.java:90)
at android.graphics.drawable.LayerDrawable.mutate(LayerDrawable.java:932)
at android.graphics.drawable.RippleDrawable.mutate(RippleDrawable.java:891)
at android.view.View.applyBackgroundTint(View.java:16324)
at android.view.View.setBackgroundDrawable(View.java:16193)
at android.support.design.widget.FloatingActionButton.access$201(FloatingActionButton.java:56)
at android.support.design.widget.FloatingActionButton$1.setBackgroundDrawable(FloatingActionButton.java:118)
at android.support.design.widget.FloatingActionButtonLollipop.setBackgroundDrawable(FloatingActionButtonLollipop.java:75)
at android.support.design.widget.FloatingActionButton.<init>(FloatingActionButton.java:131)
at android.support.design.widget.FloatingActionButton.<init>(FloatingActionButton.java:79)
... 27 more

The only line that points to my app is where it inflates the xml file, and the line in that file which is my FloatingActionButton.

   <android.support.design.widget.FloatingActionButton
        android:id=\"@+id/myFABSubCat\"
        android:layout_width=\"wrap_content\"
        android:layout_height=\"wrap_content\"
        android:layout_alignParentBottom=\"true\"
        android:layout_alignParentEnd=\"true\"
        android:layout_alignParentRight=\"true\"
        android:layout_margin=\"16dp\"
        android:backgroundTint=\"@color/accent\"
        android:src=\"@drawable/add_icon\"
        app:borderWidth=\"0dp\"
        app:elevation=\"4sp\" />

Extra info:

Here is my app theme:

<resources>

    <!-- Base application theme. -->
    <style name=\"MBTIAppTheme\" parent=\"Theme.AppCompat.Light.NoActionBar\">
        <item name=\"colorPrimary\">@color/primary</item>
        <item name=\"colorPrimaryDark\">@color/primaryDark</item>
        <item name=\"colorAccent\">@color/accent</item>
        <item name=\"android:windowContentOverlay\">@null</item>
    </style>

    <style name=\"ThemeNoActionBar\" parent=\"MBTIAppTheme\">
        <item name=\"windowActionBar\">false</item>
    </style>

</resources>

Yes, I am using an AppCompatActivity.

I noticed I am using an older version of appcompat:

com.android.support:appcompat-v7:22.1.1

This seems to be up to date:

compile \'com.android.support:design:22.2.0\'

Also,

minSdkVersion 16
targetSdkVersion 22

Now, I do set the Visibility to GONE in some case for my FAB, but this is after it inflates so that can\'t be the issue.

Now, this works with my 5.1 device, but the users who have issues have 5.0.

Is this a known bug or maybe I am doing something wrong?

回答1:

com.android.support:appcompat-v7:21+ added support for tinting widgets on devices running pre android 5.1 (API Level 21). To make use of it make sure you extend or set the AppCompat Theme and use app:backgroundTint instead of android:backgroundTint.

Example:

<android.support.design.widget.FloatingActionButton 
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_margin="16dp"
    android:src="@drawable/icon"
    app:backgroundTint="@color/accent"
    app:borderWidth="0dp" />

回答2:

Just replace

<android.support.design.widget.FloatingActionButton 
...
...
android:backgroundTint
/>

to

<android.support.design.widget.FloatingActionButton 
...
...
app:backgroundTint
/>

回答3:

If you're using a VectorDrawableCompat (Vector asset) you should use:

app:srcCompat="@drawable/x"

instead of:

android:src="@drawable/x"

回答4:

I had the same issue and tried different solution. But the one that worked for me was to ensure that appcompat and design support library versions are the same. for example:

compile 'com.android.support:appcompat-v7:23.2.0'
compile 'com.android.support:design:23.2.0'

回答5:

Another way to get this message is if you accidentally specified different versions of the appcompat library in different modules. This is likely to happen when you create a new module, since Android Studio defaults to the most current version.

For a tidy way of managing this in multi-module projects, see: In Gradle, how do I declare common dependencies in a single place?

回答6:

Just change android to app:

android:backgroundTint="@color/accent"

To:

app:backgroundTint="@color/accent"

回答7:

in my case, it was because of the false configuration of activity theme. problem was solved after i changed app theme to Theme.AppCompat.xxx.

来源：https://stackoverflow.com/questions/30870443/inflateexception-with-floatingactionbutton-from-official-design-library