在Manifest文件中指定 screenOrientation
android:screenOrientationThe orientation of the activity's display on the device. The system ignores this attribute if the activity is running in multi-window mode.
The value can be any one of the following strings:
<activity> | Android Developers (google.cn)
Activity在屏幕当中显示的方向。属性值可以是下表中列出的一个值：
- “unspecified” 默认值，由系统来选择方向。它的使用策略，以及由于选择时特定的上下文环境，可能会因为设备的差异而不同。
- “user” 使用用户当前首选的方向。
- “landscape” 横向显示（宽度比高度要大）
- “portrait” 纵向显示（高度比宽度要大）
- “reverseLandscape” 与正常的横向方向相反显示，在API Level 9中被引入。
- “reversePortrait” 与正常的纵向方向相反显示，在API Level 9中被引入。
- “sensorLandscape” 横向显示，但是基于设备传感器，既可以是按正常方向显示，也可以反向显示，在API Level9中被引入。
- “sensorPortrait” 纵向显示，但是基于设备传感器，既可以是按正常方向显示，也可以反向显示，在API Level 9中被引入。
- “sensor” 显示的方向是由设备的方向传感器来决定的。显示方向依赖与用户怎样持有设备；当用户旋转设备时，显示的方向会改变。但是，默认情况下，有些设备不会在所有的四个方向上都旋转，因此要允许在所有的四个方向上都能旋转，就要使用fullSensor属性值。
- “fullSensor” 显示的方向（4个方向）是由设备的方向传感器来决定的，除了它允许屏幕有4个显示方向之外，其他与设置为“sensor”时情况类似，不管什么样的设备，通常都会这么做。例如，某些设备通常不使用纵向倒转或横向反转，但是使用这个设置，还是会发生这样的反转。这个值在API Level 9中引入。
- “nosensor” 屏幕的显示方向不会参照物理方向传感器。传感器会被忽略，所以显示不会因用户移动设备而旋转。除了这个差别之外，系统会使用与“unspecified”设置相同的策略来旋转屏幕的方向。
注意：在给这个属性设置的值是“landscape”或portrait的时候，要考虑硬件对Activity运行的方向要求。正因如此，这些声明的值能够被诸如Google Play这样的服务所过滤，以便应用程序只能适用于那些支持Activity所要求的方向的设备。例如，如果声明了“landscape”、“reverseLandscape”、或“sensorLandscape”，那么应用程序就只能适用于那些支持横向显示的设备。但是，还应该使用元素来明确的声明应用程序所有的屏幕方向是纵向的还是横行的。例如：<uses-feature android:name=”android.hardware.screen.portrait”/>。这个设置由Google Play提供的纯粹的过滤行为，并且在设备仅支持某个特定的方向时，平台本身并不控制应用程序是否能够被按照。
"unspecified" |
The default value. The system chooses the orientation. The policy it uses, and therefore the choices made in specific contexts, might differ from device to device. |
"behind" |
The same orientation as the activity that's immediately beneath it in the activity stack. |
"landscape" |
Landscape orientation (the display is wider than it is tall). |
"portrait" |
Portrait orientation (the display is taller than it is wide). |
"reverseLandscape" |
Landscape orientation in the opposite direction from normal landscape. Added in API level 9. |
"reversePortrait" |
Portrait orientation in the opposite direction from normal portrait. Added in API level 9. |
"sensorLandscape" |
Landscape orientation, but can be either normal or reverse landscape based on the device sensor. The sensor is used even if the user has locked sensor-based rotation. Added in API level 9. |
"sensorPortrait" |
Portrait orientation, but can be either normal or reverse portrait based on the device sensor. The sensor is used even if the user has locked sensor-based rotation. However, depending on the device configuration, upside-down rotation might not be allowed. Added in API level 9. |
"userLandscape" |
Landscape orientation, but can be either normal or reverse landscape based on the device sensor and the user's preference. Added in API level 18. |
"userPortrait" |
Portrait orientation, but can be either normal or reverse portrait based on the device sensor and the user's preference. However, depending on the device configuration, upside-down rotation might not be allowed. Added in API level 18. |
"sensor" |
The device orientation sensor determines the orientation. The orientation of the display depends on how the user is holding the device. It changes when the user rotates the device. Some devices, though, don't rotate to all four possible orientations, by default. To use all four orientations, use "fullSensor". The sensor is used even if the user locked sensor-based rotation. |
"fullSensor" |
The device orientation sensor determines the orientation for any of the four orientations. This is similar to "sensor", except this allows for any of the four possible screen orientations regardless of what the device normally supports. For example, some devices don't normally use reverse portrait or reverse landscape, but this enables those orientations. Added in API level 9. |
"nosensor" |
The orientation is determined without reference to a physical orientation sensor. The sensor is ignored, so the display doesn't rotate based on how the user moves the device. |
"user" |
The user's current preferred orientation. |
"fullUser" |
If the user has locked sensor-based rotation, this behaves the same as user, otherwise it behaves the same as fullSensor and allows any of the four possible screen orientations. Added in API level 18. |
"locked" |
Locks the orientation to its current rotation, whatever that is. Added in API level 18. |
