<?xml version="1.0" encoding="utf-8"?>

<shapexmlns:android="http://schemas.android.com/apk/res/android"

    android:shape="rectangle">

    <gradient

        android:startColor="#FFFF0000"

        android:endColor="#80FF00FF"

        android:angle="45"/>

    <paddingandroid:left="7dp"

        android:top="7dp"

        android:right="7dp"

        android:bottom="7dp"/>

    <cornersandroid:radius="8dp"/>

</shape>

<TextView

    android:background="@drawable/gradient_box"

    android:layout_height="wrap_content"

    android:layout_width="wrap_content"/>

Resources res =getResources();

Drawable shape = res.getDrawable(R.drawable.gradient_box);

TextView tv =(TextView)findViewByID(R.id.textview);

tv.setBackground(shape);

<?xml version="1.0" encoding="utf-8"?>

<shape android:shape="rectangle" xmlns:android="http://schemas.android.com/apk/res/android">

    <!-- 渐变 -->

    <!-- 详细内容 http://developer.android.com/guide/topics/resources/drawable-resource.html#Shape -->

    <gradient

        android:startColor="#0000ff"

        android:endColor="#00bfff"

        android:angle="45"

        android:centerX="0.5"/>

    <!-- 圆角 -->

    <corners

        android:radius="8dp"/>

    <!-- 外边间距 -->

     <padding android:left="7dp"

        android:top="7dp"

        android:right="7dp"

        android:bottom="7dp" />

        <!-- 描边 -->

            <stroke  

                android:width="2dp"

                android:color="#dcdcdc"

                android:dashWidth="5dp"

                android:dashGap="0dp" />

            <!-- dashgap 表示间隔 有了间隔就成了虚线 -->

</shape>