首先在布局文件定义Progressbar

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.christmas.circleprogressbar.MainActivity">
  <ProgressBar
  android:id="@+id/pb_count_down_bottom"
  style="?android:attr/progressBarStyleHorizontal"
  android:layout_width="50dp"
  android:layout_height="50dp"
  android:layout_below="@+id/fl_count_down_middle"
  android:layout_centerHorizontal="true"
  android:layout_marginTop="30dp"
  android:progressDrawable="@drawable/circle_progress_bar"
  tools:max="100"
  tools:progress="50" />
</RelativeLayout>

然后定义progressDrawable文件

<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
android:fromDegrees="270"
android:toDegrees="270">
<shape
  android:innerRadiusRatio="2.5"
  android:shape="ring"
  android:thickness="2dp"
  android:useLevel="true">

 <gradient
    android:angle="0"
    android:endColor="#4285f4"
    android:startColor="#4285f4"
    android:type="sweep"
    android:useLevel="false" />
</shape>
</rotate>