报错信息如下：
:app:installDebug
Installing APK 'app-debug.apk' on 'Redmi 3S - 6.0.1'
Unable to install D:\ReactNative-Workspace\FirstRNProject\android\app\build\outp
uts\apk\app-debug.apk
com.android.ddmlib.InstallException: Failed to establish session
at com.android.ddmlib.Device.installPackages(Device.java:894)
at com.android.builder.testing.ConnectedDevice.installPackages(Connected
Device.java:113)
........ 中间一大堆报错信息省略 .........
:app:installDebug FAILED
FAILURE: Build failed with an exception.
What went wrong:
Execution failed for task ':app:installDebug'.
com.android.builder.testing.api.DeviceException: com.android.ddmlib.InstallExc
eption: Failed to establish session
一直跳错误信息：
解决过程：手机型号（红米3S，系统MIUI 8）；先检查了一下开发者选项，USB调试、未知源 都是开启的；
然后发现 “启用MIUI优化”这一项是开启的，把它关掉（设置----更多设置----开发者选项----启用MIUI优化 关闭）
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