Null Pointer exception about superslim

[TonicArtos]

It looks like your adapter is providing views without layout parameters. Whilst I prefer this to not be the case, I agree that it is a bug for the library to crash on it.

[kcorwin]

Just a quick observation - I was also getting this exception, even when my views had layout params set. Turned out the problem is that my layoutParams.sectionFirstPosition in my views were incorrect - I was setting it to the index of the first (non-header) item in the section, when it's supposed to be the position of the section header itself.

[ab-helly]

I'm also getting this error in case if there is single item in the list

[TonicArtos]

This is a problem with the scroll indicator computation, which has been removed for now as it is bad, inaccurate, and will be wholly replaced after the section layout manager design changes.

[jesielin]

i encounter the similar problem:
java.lang.NullPointerException: Attempt to read from field 'int android.view.ViewGroup$LayoutParams.width' on a null object reference
at android.view.ViewGroup$LayoutParams.(ViewGroup.java:6403)
at android.view.ViewGroup$MarginLayoutParams.(ViewGroup.java:6685)
at android.support.v7.widget.RecyclerView$LayoutParams.(RecyclerView.java:7420)
at com.tonicartos.superslim.LayoutManager$LayoutParams.(LayoutManager.java:1819)
at com.tonicartos.superslim.GridSLM$LayoutParams.(GridSLM.java:506)
at com.tonicartos.superslim.GridSLM$LayoutParams.from(GridSLM.java:520)
at com.zihexin.cwapp.activity.CityActivity$CountryAdapter.onBindViewHolder(CityActivity.java:111)
at com.zihexin.cwapp.activity.CityActivity$CountryAdapter.onBindViewHolder(CityActivity.java:70)
at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:4402)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:3717)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:3609)
at com.tonicartos.superslim.LayoutState.getView(LayoutState.java:44)
at com.tonicartos.superslim.LayoutManager.layoutChildren(LayoutManager.java:1316)
at com.tonicartos.superslim.LayoutManager.onLayoutChildren(LayoutManager.java:264)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:2118)
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:2415)
at android.view.View.layout(View.java:15596)
at android.view.ViewGroup.layout(ViewGroup.java:4966)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:15596)
at android.view.ViewGroup.layout(ViewGroup.java:4966)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
at android.view.View.layout(View.java:15596)
at android.view.ViewGroup.layout(ViewGroup.java:4966)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:15596)
at android.view.ViewGroup.layout(ViewGroup.java:4966)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
at android.view.View.layout(View.java:15596)
at android.view.ViewGroup.layout(ViewGroup.java:4966)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:15596)
at android.view.ViewGroup.layout(ViewGroup.java:4966)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
at android.view.View.layout(View.java:15596)
at android.view.ViewGroup.layout(ViewGroup.java:4966)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2072)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1829)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1054)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5779)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
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.M
and i think i solve it
in onCreateViewHolder method, i use View.inflate(mContext,R.layout.item_country_content,null); before to get the itemView,and then i got the problem,finally,i change to this:
view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_country_content, viewGroup, false); and problem solved
just write here to help others

[TonicArtos]

@jesielin What you encountered is a bug. The configuration you had should had caused the layout manager to assign sensible default layout parameters to the item. This bug will be tracked in #74.