RecyclerView方法onCreateViewHolder()和onBindViewHolder()没有调用

原因：至今小编都未知，初步分析为

android.support.constraint.ConstraintLayout有bug

打印log getItemCount() > 0

RecyclerViewAdapter 构造方法执行了

RecyclerView 基本的都设置了，还是不行。

最后只能修改布局文件，去掉布局文件中的外层包裹

<android.support.constraint.ConstraintLayout 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"
android:layout_width="match_parent"
android:layout_height="match_parent">

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:orientation="vertical">
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="@dimen/fab_margin"
android:src="@drawable/to_top22"
/>
</LinearLayout>
</android.support.constraint.ConstraintLayout>

数据不显示时的布局文件

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<include
layout="@layout/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/white"
android:clickable="true"
android:orientation="vertical">
<android.support.v4.widget.SwipeRefreshLayout
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent" />
</android.support.v4.widget.SwipeRefreshLayout>
</LinearLayout>
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:orientation="vertical">
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="@dimen/fab_margin"
android:src="@drawable/to_top22"
/>
</LinearLayout>
</android.support.constraint.ConstraintLayout>