从LayerDrawable例外

Question

我有一个Android应用程序，使用Android支持库版本23.2.1和一切工作正常。不过，我昨天更新了Android支持库版本为25.2.0，并意识到一些用户正在获取此异常（通过Fabric crashlytics），但我无法复制它。

这里是崩溃日志：

Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'android.graphics.drawable.Drawable android.graphics.drawable.Drawable$ConstantState.newDrawable(android.content.res.Resources)' on a null object reference 
    at android.graphics.drawable.LayerDrawable$ChildDrawable.<init>(LayerDrawable.java:959) 
    at android.graphics.drawable.LayerDrawable$LayerState.<init>(LayerDrawable.java:1007) 
    at android.graphics.drawable.LayerDrawable.createConstantState(LayerDrawable.java:133) 
    at android.graphics.drawable.LayerDrawable.<init>(LayerDrawable.java:126) 
    at android.graphics.drawable.LayerDrawable$LayerState.newDrawable(LayerDrawable.java:1048) 
    at android.content.res.Resources.getCachedDrawableLocked(Resources.java:2777) 
    at android.content.res.Resources.getCachedDrawable(Resources.java:2745) 
    at android.content.res.Resources.loadDrawable(Resources.java:2586) 
    at android.content.res.Resources.getDrawable(Resources.java:900) 
    at android.content.Context.getDrawable(Context.java:408) 
    at android.support.v4.content.ContextCompatApi21.getDrawable(ContextCompatApi21.java:30) 
    at android.support.v4.content.ContextCompat.getDrawable(ContextCompat.java:372) 
    at android.support.v7.widget.AppCompatDrawableManager.getDrawable(AppCompatDrawableManager.java:202) 
    at android.support.v7.widget.AppCompatDrawableManager.getDrawable(AppCompatDrawableManager.java:190) 
    at android.support.v7.content.res.AppCompatResources.getDrawable(AppCompatResources.java:100) 
    at android.support.v7.view.menu.MenuItemImpl.getIcon(MenuItemImpl.java:425) 
    at android.support.v7.view.menu.ActionMenuItemView.initialize(ActionMenuItemView.java:129) 
    at android.support.v7.widget.ActionMenuPresenter.bindItemView(ActionMenuPresenter.java:211) 
    at android.support.v7.view.menu.BaseMenuPresenter.getItemView(BaseMenuPresenter.java:186) 
    at android.support.v7.widget.ActionMenuPresenter.getItemView(ActionMenuPresenter.java:197) 
    at android.support.v7.widget.ActionMenuPresenter.flagActionItems(ActionMenuPresenter.java:479) 
    at android.support.v7.view.menu.MenuBuilder.flagActionItems(MenuBuilder.java:1160) 
    at android.support.v7.view.menu.BaseMenuPresenter.updateMenuView(BaseMenuPresenter.java:95) 
    at android.support.v7.widget.ActionMenuPresenter.updateMenuView(ActionMenuPresenter.java:234) 
    at android.support.v7.view.menu.MenuBuilder.dispatchPresenterUpdate(MenuBuilder.java:292) 
    at android.support.v7.view.menu.MenuBuilder.onItemsChanged(MenuBuilder.java:1047) 
    at android.support.v7.view.menu.MenuBuilder.startDispatchingItemsChanged(MenuBuilder.java:1074) 
    at android.support.v7.app.ToolbarActionBar.populateOptionsMenu(ToolbarActionBar.java:460) 
    at android.support.v7.app.ToolbarActionBar$1.run(ToolbarActionBar.java:61) 
    at android.os.Handler.handleCallback(Handler.java:815) 
    at android.os.Handler.dispatchMessage(Handler.java:104) 
    at android.os.Looper.loop(Looper.java:194) 
    at android.app.ActivityThread.main(ActivityThread.java:5637) 
    at java.lang.reflect.Method.invoke(Method.java) 
    at java.lang.reflect.Method.invoke(Method.java:372) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:959) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:754) 

这似乎与菜单视图做。菜单选项的布局是：

<?xml version="1.0" encoding="utf-8"?> 
<menu xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    tools:context=".tablet.ui.navimenu.ContainerActivity"> 

    <item 
     android:id="@+id/memo_fragment" 
     android:icon="@drawable/ic_class_white_24dp" 
     android:orderInCategory="100" 
     android:title="@string/memo_fragment" 
     app:showAsAction="always" /> 

    <item 
     android:id="@+id/notification_fragment" 
     android:icon="@drawable/layerlist_menu_notification" 
     android:orderInCategory="200" 
     android:title="@string/notification_fragment" 
     app:showAsAction="always" /> 

</menu> 

layerlist_menu_notification布局与徽章的图标：

<?xml version="1.0" encoding="utf-8"?> 
<layer-list xmlns:android="http://schemas.android.com/apk/res/android"> 
    <item 
     android:id="@+id/ic_notification" 
     android:drawable="@drawable/ic_notifications_white_24dp" 
     android:gravity="center" /> 

    <!-- set a place holder Drawable so android:drawable isn't null --> 
    <item 
     android:id="@+id/ic_badge" 
     android:drawable="@drawable/ic_notifications_white_24dp" /> 
</layer-list> 

任何想法，错在何处？

Answer 1

尝试更改您使用的矢量可绘制在的build.gradle

compileSdkVersion 25 
buildToolsVersion "25.0.2" 
compile 'com.android.support:appcompat-v7:25.1.0' 
compile 'com.android.support:design:25.1.0' 
compile 'com.android.support:support-v4:25.1.0'