PickerLayoutManager error

[syusikoku]

java.lang.IndexOutOfBoundsException: Invalid item position 0(0). Item count:0 android.support.v7.widget.RecyclerView{196c0bf2 VFED.... ......I. 0,0-0,0 #7f090085 app:id/recycler1}, adapter:com.example.slmg.fragments.PickerFragment$MyAdapter@2dd10243, layout:com.example.lmg.lib.PickerLayoutManager@338090c0, context:com.example.slmg.MainActivity@20df3294
at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5885)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5858)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5854)
at com.example.lmg.lib.PickerLayoutManager.onMeasure(PickerLayoutManager.java:68)
at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:3321)
at android.view.View.measure(View.java:17430)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:1083)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:615)
at android.view.View.measure(View.java:17430)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at android.support.v7.widget.CardView.onMeasure(CardView.java:260)
at android.view.View.measure(View.java:17430)
at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:727)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:463)
at android.view.View.measure(View.java:17430)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at android.view.View.measure(View.java:17430)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17430)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
at android.view.View.measure(View.java:17430)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17430)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at android.view.View.measure(View.java:17430)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17430)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2560)
at android.view.View.measure(View.java:17430)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2001)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1166)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1372)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1054)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5779)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)

com.example.lmg.lib.PickerLayoutManager#onMeasure中出错：
View view = recycler.getViewForPosition(0);
越界,修改如下之后:
if (getItemCount() != 0 && mItemCount != 0 && state.getItemCount() > 0) {
View view = recycler.getViewForPosition(0);
measureChildWithMargins(view, widthSpec, heightSpec);
}
测量的结果又有问题

[KunMinX]

+1

[KunMinX]

很简单，我的做法是，将 getItemCount 改成 state.getItemCount，
并且在数据的头尾都加上空字符串，即可。

[sankemao]

在pickerLayoutManager中添加

    @Override
    public boolean isAutoMeasureEnabled() {
        return false;
    }