PullToRefreshListView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" android:layout_width="match_parent"    android:layout_height="match_parent">    <com.handmark.pulltorefresh.library.PullToRefreshListView        android:id="@+id/pull_refresh_list"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:cacheColorHint="#00000000" /></android.support.constraint.ConstraintLayout>