<dimen name="audio_course_item_seek_bar_progress_height">6dp</dimen>
<dimen name="audio_course_item_seek_bar_radius">2dp</dimen>
<dimen name="audio_seek_bar_thumb_size">20dp</dimen>
<dimen name="audio_seek_bar_thumb_ring_width">4dp</dimen>

shape_thumb_round_1.xml # 靜態(tài)thumb
layers_seek_bar_progress_1.xml
layers_thumb_ring_sweep_1.xml
rotate_thumb_1.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <solid android:color="#ffffff" />
    <stroke
        android:width="@dimen/audio_seek_bar_thumb_ring_width"
        android:color="#7095fc" />
    <size
        android:width="@dimen/audio_seek_bar_thumb_size"
        android:height="@dimen/audio_seek_bar_thumb_size" />
</shape>

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="oval">
            <size
                android:width="@dimen/audio_seek_bar_thumb_size"
                android:height="@dimen/audio_seek_bar_thumb_size" />
            <solid android:color="#ffffff" />
        </shape>
    </item>
    <item>
        <shape
            android:innerRadius="4dp"
            android:thicknessRatio="6"
            android:shape="ring"
            android:useLevel="false">
            <gradient
                android:endColor="#ffffff"
                android:startColor="#7095fc"
                android:type="sweep" />
            <size
                android:width="@dimen/audio_seek_bar_thumb_size"
                android:height="@dimen/audio_seek_bar_thumb_size" />
        </shape>
    </item>
</layer-list>

<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
    android:drawable="@drawable/layers_thumb_ring_sweep_1"
    android:duration="100"
    android:fromDegrees="0"
    android:pivotX="50%"
    android:pivotY="50%"
    android:toDegrees="-360" />

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@android:id/background">
        <shape>
            <size
                android:width="5dp"
                android:height="@dimen/audio_course_item_seek_bar_progress_height" />
            <solid android:color="#e1e5e8" />
        </shape>
    </item>
    <item android:id="@android:id/secondaryProgress">
        <clip>
            <shape>
                <solid android:color="#b7bdc8" />
            </shape>
        </clip>
    </item>
    <item android:id="@android:id/progress">
        <clip>
            <shape>
                <gradient
                    android:angle="0"
                    android:centerColor="#b8cafd"
                    android:endColor="#86a4fd"
                    android:startColor="#eef2ff" />
            </shape>
        </clip>
    </item>
</layer-list>

<SeekBar
    android:id="@+id/play_sb"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="16dp"
    android:background="@null"
    android:maxHeight="@dimen/audio_course_item_seek_bar_progress_height"
    android:minHeight="@dimen/audio_course_item_seek_bar_progress_height"
    android:progress="40"
    android:progressDrawable="@drawable/layers_seek_bar_progress_1"
    android:thumb="@drawable/shape_thumb_round_1"
    app:layout_constraintTop_toTopOf="parent" />

private RotateDrawable mRotateThumbDrawable; //  加載中的thumb，由Activity來(lái)持有這個(gè)drawable
private Drawable mSolidThumb;
private ObjectAnimator mThumbAnimator; // 控制動(dòng)畫(huà)
// ...
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mBinding = DataBindingUtil.setContentView(this, R.layout.act_seekbar_1);// ...
        mRotateThumbDrawable = (RotateDrawable) AppCompatResources.getDrawable(getApplicationContext(), R.drawable.rotate_thumb_1);
        mSolidThumb = AppCompatResources.getDrawable(getApplicationContext(), R.drawable.shape_thumb_round_1);
    }

mBinding.playSb.setThumb(mSolidThumb);

mBinding.playSb.setThumb(mRotateThumbDrawable);
mThumbAnimator = ObjectAnimator.ofInt(mRotateThumbDrawable, "level", 0, 10000);
mThumbAnimator.setDuration(1000);
mThumbAnimator.setRepeatCount(ValueAnimator.INFINITE);
mThumbAnimator.setInterpolator(new LinearInterpolator());
mThumbAnimator.start();

@Override
protected void onDestroy() {
    if (null != mThumbAnimator) {
        mThumbAnimator.cancel();
    }
    super.onDestroy();
}