java.lang.ClassCastException: You should only use a GridLayoutManager with GridRecyclerView.

[zubairsps]

Just import this sample to android studio, in activity_main I am getting following error in xml

java.lang.ClassCastException: You should only use a GridLayoutManager with GridRecyclerView.
    at com.antonioleiva.materializeyourapp.widgets.GridRecyclerView.setLayoutManager(GridRecyclerView.java:56)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.android.layoutlib.bridge.util.ReflectionUtils.invoke(ReflectionUtils.java:45)
    at com.android.layoutlib.bridge.android.support.RecyclerViewUtil.setProperty(RecyclerViewUtil.java:126)
    at com.android.layoutlib.bridge.android.support.RecyclerViewUtil.setProperty(RecyclerViewUtil.java:120)
    at com.android.layoutlib.bridge.android.support.RecyclerViewUtil.setLayoutManager(RecyclerViewUtil.java:78)
    at com.android.layoutlib.bridge.android.support.RecyclerViewUtil.setAdapter(RecyclerViewUtil.java:59)
    at android.view.BridgeInflater.setupViewInContext(BridgeInflater.java:292)
    at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:188)
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
    at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:835)
    at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:70)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:811)
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
    at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:838)
    at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:70)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:811)
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:394)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:223)
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:426)
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:350)
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:510)
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:498)
    at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:888)
    at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:498)
    at com.android.tools.idea.rendering.RenderTask.access$600(RenderTask.java:72)
    at com.android.tools.idea.rendering.RenderTask$3.call(RenderTask.java:610)
    at com.android.tools.idea.rendering.RenderTask$3.call(RenderTask.java:607)
    at com.android.tools.idea.rendering.RenderService.runRenderAction(RenderService.java:362)
    at com.android.tools.idea.rendering.RenderTask.render(RenderTask.java:607)
    at com.android.tools.idea.rendering.RenderTask.render(RenderTask.java:629)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.doRender(AndroidLayoutPreviewToolWindowManager.java:652)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.access$1700(AndroidLayoutPreviewToolWindowManager.java:80)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7$1.run(AndroidLayoutPreviewToolWindowManager.java:594)
    at com.intellij.openapi.progress.impl.CoreProgressManager$2.run(CoreProgressManager.java:152)
    at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:452)
    at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:402)
    at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:54)
    at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:137)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7.run(AndroidLayoutPreviewToolWindowManager.java:589)
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:320)
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:310)
    at com.intellij.util.ui.update.MergingUpdateQueue$2.run(MergingUpdateQueue.java:254)
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:269)
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:227)
    at com.intellij.util.ui.update.MergingUpdateQueue.run(MergingUpdateQueue.java:217)
    at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.java:238)
    at com.intellij.util.Alarm$Request$1.run(Alarm.java:351)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

[zubairsps]

I have replaced in activity_main.xml

<com.antonioleiva.materializeyourapp.widgets.GridRecyclerView
            android:id="@+id/recycler"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layoutAnimation="@anim/grid_layout_animation"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"/>

With

<android.support.v7.widget.RecyclerView
            android:id="@+id/recycler"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"/>

Now your sample is working fine but I cannot understand why its giving exception for GridRecyclerView?

[abiemann]

@zubairsps it's an intentional exception, check line 56 within GridRecyclerView.java
https://github.com/antoniolg/MaterializeYourApp/blob/master/app/src/main/java/com/antonioleiva/materializeyourapp/widgets/GridRecyclerView.java#L56