Android中方向问题（转变方向）以及 configChanges 配置不管用问题

最新推荐文章于 2017-11-01 10:09:25 发布

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#Android中orientation方 #configChanges 配置不管用问 #configChanges失效

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本文详细介绍了在Android中设置屏幕方向的两种方式，包括在AndroidManifest.xml中配置activity的android:orientation属性和在Activity的onCreate()方法中使用setRequestedOrientation()。讨论了各种方向属性值的含义，如landscape、portrait、sensor等，并解释了当配置configChanges时，如何处理屏幕旋转生命周期问题，避免Activity重建。此外，还提到了在onConfigurationChanged()方法中监听和处理配置变化的方法。

1. 有两种设置屏幕方向的方式：

1）在AndroidManifest.xml 中配置activity时增加 android:orientation属性即可，如：

xxx代表的值可选项如下：

Constant	Value	Description
`unspecified`	-1	No preference specified: let the system decide the best orientation. This will either be the orientation selected by the activity below, or the user's preferred orientation if this activity is the bottom of a task. If the user explicitly turned off sensor based orientation through settings sensor based device rotation will be ignored. If not by default sensor based orientation will be taken into account and the orientation will changed based on how the user rotates the device
`landscape`	0	Would like to have the screen in a landscape orientation: that is, with the display wider than it is tall, ignoring sensor data.
`portrait`	1	Would like to have the screen in a portrait orientation: that is, with the display taller than it is wide, ignoring sensor data.
`user`	2	Use the user's current preferred orientation of the handset.
`behind`	3	Keep the screen in the same orientation as whatever is behind this activity.
`sensor`	4	Orientation is determined by a physical orientation sensor: the display will rotate based on how the user moves the device.
`nosensor`	5	Always ignore orientation determined by orientation sensor: the display will not rotate when the user moves the device.
`sensorLandscape`	6	Would like to have the screen in landscape orientation, but can use the sensor to change which direction the screen is facing.
`sensorPortrait`	7	Would like to have the screen in portrait orientation, but can use the sensor to change which direction the screen is facing.
`reverseLandscape`	8	Would like to have the screen in landscape orientation, turned in the opposite direction from normal landscape.
`reversePortrait`	9	Would like to have the screen in portrait orientation, turned in the opposite direction from normal portrait.
`fullSensor`	10	Orientation is determined by a physical orientation sensor: the display will rotate based on how the user moves the device. This allows any of the 4 possible rotations, regardless of what the device will normally do (for example some devices won't normally use 180 degree rotation).

2）在Activity 的 onCreate()方法中，注意在setContentView(R.layout.xx)之后，调用 setRequestedOrientation(int requestOrientation)

这个参数值在类 ActivityInfo 中定义了很多常量：

int SCREEN_ORIENTATION_BEHIND
int SCREEN_ORIENTATION_FULL_SENSOR
int SCREEN_ORIENTATION_LANDSCAPE
int SCREEN_ORIENTATION_NOSENSOR Constant corresponding to nosensor in the screenOrientation attribute.
int SCREEN_ORIENTATION_PORTRAIT Constant corresponding to portrait in the screenOrientation attribute.
int SCREEN_ORIENTATION_REVERSE_LANDSCAPE Constant corresponding to reverseLandscape in the screenOrientation attribute.
int SCREEN_ORIENTATION_REVERSE_PORTRAIT Constant corresponding to reversePortrait in the screenOrientation attribute.
int SCREEN_ORIENTATION_SENSOR Constant corresponding to sensor in the screenOrientation attribute.
int SCREEN_ORIENTATION_SENSOR_LANDSCAPE Constant corresponding to sensorLandscape in the screenOrientation attribute.
int SCREEN_ORIENTATION_SENSOR_PORTRAIT Constant corresponding to sensorPortrait in the screenOrientation attribute.
int SCREEN_ORIENTATION_UNSPECIFIED Constant corresponding to unspecified in the screenOrientation attribute.
int SCREEN_ORIENTATION_USER Constant corresponding to user in the screenOrientation attribute.