通常我们的应用只会设计成横屏或者竖屏，锁定横屏或竖屏的方法是在manifest.xml文件中设定属性android:screenOrientation为"landscape"或"portrait"：
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:screenOrientation="landscape">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
其实screenOrientation还可以设置成很多值：
android:screenOrientation = ["unspecified" | "behind" |
"landscape" | "portrait" |
"reverseLandscape" | "reversePortrait" |
"sensorLandscape" | "sensorPortrait" |
"userLandscape" | "userPortrait" |
"sensor" | "fullSensor" | "nosensor" |
"user" | "fullUser" | "locked"]
其中sensorLandscape就是横屏根据重力上下翻转，sensorPortrait竖屏根据重力上下翻转。
如果有兴趣，你也可以试试其他的值哦...