android:configChanges="orientation|keyboardHidden"的使用

1. 了解android:configChanges 的属性

通过设置这个属性可以使Activity捕捉设备状态变化,以下是可以被识别的内容:  

CONFIG_FONT_SCALE
CONFIG_MCC
CONFIG_MNC
CONFIG_LOCALE
CONFIG_TOUCHSCREEN
CONFIG_KEYBOARD
CONFIG_NAVIGATION
CONFIG_ORIENTATION
设置方法:将下列字段用“|”符号分隔开,例如:“locale|navigation|orientation

Value Description
“mcc“ The IMSI mobile country code (MCC) has changed — that is, a SIM hasbeen detected and updated the MCC.移动国家号码,由三位数字组成,每个国家都有自己独立的MCC,可以识别手机用户所属国家。
“mnc“ The IMSI mobile network code (MNC) has changed — that is, a SIM hasbeen detected and updated the MNC.移动网号,在一个国家或者地区中,用于区分手机用户的服务商。
“locale“ The locale has changed — for example, the user has selected a new language that text should be displayed in.用户所在地区发生变化。
“touchscreen“ The touchscreen has changed. (This should never normally happen.)
“keyboard“ The keyboard type has changed — for example, the user has plugged in an external keyboard.键盘模式发生变化,例如:用户接入外部键盘输入
“keyboardHidden“ The keyboard accessibility has changed — for example, the user has slid the keyboard out to expose it.用户打开手机硬件键盘
“navigation“ The navigation type has changed. (This should never normally happen.)
“orientation“ The screen orientation has changed — that is, the user has rotated the device.设备旋转,横向显示和竖向显示模式切换。
“fontScale“ The font scaling factor has changed — that is, the user has selected a new global font size.全局字体大小缩放发生改变

在Activity中添加了 android:configChanges属性,目的是当所指定属性(Configuration Changes)发生改变时,通知程序调用 onConfigurationChanged()函数。

2. android:configChanges="orientation|keyboardHidden"的使用 

当在activity加上android:configChanges="keyboardHidden|orientation"属性,就不会重启activity.而只是调用onConfigurationChanged(Configuration newConfig).这样就可以在这个方法里调整显示方式.

在xml文件里面可以进行配置configChanges也可以在代码中动态配置 

注意:

1、不设置Activity的android:configChanges时,切屏会重新调用各个生命周期,切横屏时会执行一次,切竖屏时会执行两次
2、设置Activity的android:configChanges="orientation"时,切屏还是会重新调用各个生命周期,切横、竖屏时只会执行一次
3、设置Activity的android:configChanges="orientation|keyboardHidden"时,切屏不会重新调用各个生命周期,只会执行onConfigurationChanged方法


3. 相关问题详见:

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4. 测试源代码下载

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