Android custom control drop-down refresh instance code

Effect achieved:

Picture material:

-->First, write the pull-down refresh layout during refresh_ to_ refresh.xml:

<resources>
  <string name="app_name">PullToRefreshTest</string>
  <string name="pull_to_refresh">下拉可以刷新</string>
  <string name="release_to_refresh">释放立即刷新</string>
  <string name="refreshing">正在刷新...</string>
  <string name="not_updated_yet">暂未更新过</string>
  <string name="updated_at">上次更新于%1$s前</string>
  <string name="updated_just_Now">刚刚更新</string>
  <string name="time_error">时间有问题</string>
</resources>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/pull_to_refresh_head"
  android:layout_width="match_parent"
  android:layout_height="60dp">
  <LinearLayout
    android:layout_width="200dp"
    android:layout_height="60dp"
    android:layout_centerInParent="true"
    android:orientation="horizontal">
    <RelativeLayout
      android:layout_width="0dp"
      android:layout_height="60dp"
      android:layout_weight="3">
      <ImageView
        android:id="@+id/arrow"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:src="@mipmap/indicator_arrow" />
      <ProgressBar
        android:id="@+id/progress_bar"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_centerInParent="true"
        android:visibility="gone" />
    </RelativeLayout>
    <LinearLayout
      android:layout_width="0dp"
      android:layout_height="60dp"
      android:layout_weight="12"
      android:orientation="vertical">
      <TextView
        android:id="@+id/description"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:gravity="center_horizontal|bottom"
        android:text="@string/pull_to_refresh" />
      <TextView
        android:id="@+id/updated_at"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:gravity="center_horizontal|top"
        android:text="@string/updated_at" />
    </LinearLayout>
  </LinearLayout>
</RelativeLayout>