設定有外框的TextView

You can set a shape drawable (a rectangle) as background for the view.

<TextView android:text="Some text" android:background="@drawable/back"/>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" >
<solid android:color="#ffffff" /><stroke android:width="1dip" android:color="#4fa5d5"/></shape>

方框
And rectangle drawable back.xml (put into res/drawable folder):

You can use #00000000 for the solid color to have a transparent background. You can also use padding to separate the text from the border. for more information see:http://developer.android.com/guide/topics/resources/drawable-resource.html
圓角框

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

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

<solid android:color="#ffffffff" />

<corners android:radius="10dp" />

<padding android:left="5dp" android:top="5dp" 

android:right="5dp" android:bottom="5dp" />

</shape>

也可以將兩個合起來

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

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

<solid android:color="#404040" /><!-- 內部填充顏色 -->

<stroke android:width="3dip" android:color="#FFFFFF"/><!--外框顏色  -->

<corners android:radius="10dp" />

<padding android:left="5dp" android:top="5dp" 

android:right="5dp" android:bottom="5dp" />

</shape>