android:background="@drawable/shape"

<Button 
    android:layout_width="160dp"
    android:layout_height="wrap_content"
    android:background="@drawable/button_shape"
    android:text="圆角按钮"
    />

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >
    <solid android:color="#fff"/>
    <padding android:top="10px" android:bottom="10px"/>
    <corners android:radius="16px"/>
    <stroke android:width="1px" android:color="#000"/>
</shape>

<View 
    android:layout_width="match_parent"
    android:layout_height="5px"
    android:layout_marginTop="10dp"
    android:background="@drawable/line_shape"
    />

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="line" >
    <stroke
        android:dashGap="3dp"
        android:dashWidth="8dp"
        android:width="1dp"
        android:color="#63a219" />
    <size android:height="1dp" />
</shape>

<View 
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_marginTop="10dp"
    android:background="@drawable/gra_shape"
    />

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >

    <gradient
        android:angle="270.0"
        android:endColor="#ffffff"
        android:startColor="#000000" />

</shape>