recycle view设置item下划线

recyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.HORIZONTAL));

drawable目录下新建bg_decoration.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android"       android:shape="rectangle">    <gradient        android:centerColor="@color/colorAccent"        android:startColor="@color/colorPrimary"        android:endColor="@color/colorPrimaryDark"        android:type="linear"/>    <size android:height="3dp"/></shape>

style.xml下的主题样式中加入

<item name="android:listDivider">@drawable/bg_decoration</item>