E/AndroidRuntime: FATAL EXCEPTION: main
              Process: co.netlong.skyoto, PID: 26079
              java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
                  at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
                  at java.util.ArrayList.get(ArrayList.java:308)
                  at android.support.v7.widget.StaggeredGridLayoutManager$Span.calculateCachedStart(StaggeredGridLayoutManager.java:2357)
                  at android.support.v7.widget.StaggeredGridLayoutManager$Span.getStartLine(StaggeredGridLayoutManager.java:2374)
                  at android.support.v7.widget.StaggeredGridLayoutManager.checkSpanForGap(StaggeredGridLayoutManager.java:396)
                  at android.support.v7.widget.StaggeredGridLayoutManager.hasGapsToFix(StaggeredGridLayoutManager.java:345)
                  at android.support.v7.widget.StaggeredGridLayoutManager.checkForGaps(StaggeredGridLayoutManager.java:272)
                  at android.support.v7.widget.StaggeredGridLayoutManager.onScrollStateChanged(StaggeredGridLayoutManager.java:307)
                  at android.support.v7.widget.RecyclerView.dispatchOnScrollStateChanged(RecyclerView.java:3977)
                  at android.support.v7.widget.RecyclerView.setScrollState(RecyclerView.java:1219)
                  at android.support.v7.widget.RecyclerView.access$3900(RecyclerView.java:147)
                  at android.support.v7.widget.RecyclerView$ViewFlinger.run(RecyclerView.java:4128)
                  at android.view.Choreographer$CallbackRecord.run(Choreographer.java:777)
                  at android.view.Choreographer.doCallbacks(Choreographer.java:590)
                  at android.view.Choreographer.doFrame(Choreographer.java:559)
                  at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:763)
                  at android.os.Handler.handleCallback(Handler.java:739)
                  at android.os.Handler.dispatchMessage(Handler.java:95)
                  at android.os.Looper.loop(Looper.java:145)
                  at android.app.ActivityThread.main(ActivityThread.java:5835)
                  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:1399)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)

使用viewpager+4个fragment

每个fragment中为swiperefreshlayout+recyclerview

出现上述错误，最终错误原因不在StaggeredGridLayoutManager，而是viewpager的状态保存

解决方法：
viewpager.setOffscreenPageLimit(list.size() - 1);