出现此问题一定是V4包的问题（一天的惨痛经历总结）
错误信息：
e: ****\WeatherFragment.kt: (298, 28): Unresolved reference: context
e: ****\WifiFragment.kt: (120, 55): Unresolved reference: getColor
e: ****\WifiFragment.kt: (151, 32): Unresolved reference: checkSelfPermission
e: ****\WifiFragment.kt: (153, 17): Unresolved reference: requestPermissions
e: ****\WifiFragment.kt: (158, 5): ‘onRequestPermissionsResult’ overrides nothing
e: ****\WifiFragment.kt: (159, 15): Unresolved reference: onRequestPermissionsResult
e: ****\WifiFragment.kt: (172, 31): Unresolved reference: context
e: ****\WifiFragment.kt: (173, 37): Unresolved reference: context
e: ****\WifiFragment.kt: (182, 39): Unresolved reference: context
e: ****\WifiFragment.kt: (183, 33): Unresolved reference: context
e: ****\WifiFragment.kt: (286, 26): Unresolved reference: layoutInflater
e: ****\WifiFragment.kt: (291, 29): Unresolved reference: context
e: ****\WifiFragment.kt: (294, 44): Cannot infer a type for this parameter. Please specify it explicitly.
e: ****\WifiFragment.kt: (294, 47): Cannot infer a type for this parameter. Please specify it explicitly.
e: ****\WifiFragment.kt: (299, 44): Cannot infer a type for this parameter. Please specify it explicitly.
e: ****\WifiFragment.kt: (299, 47): Cannot infer a type for this parameter. Please specify it explicitly.
从上面的错误信息是可以推断出V4包有问题的。
尊重原创，转载请注明出处： http://blog.csdn.net/qq137722697
背景
项目中需要引入一个第三方的库，demo里面竟然采用离线导入v4.jar的方式引入项目（android-support-v4.jar），本身我们项目已经有V7包了，于是我就把app/build.gradle的依赖中注释掉
implementation files('libs/android-support-v4.jar')
运行还是这个问题，我一开始怀疑是项目某个类有问题，各种找，找了大半天，终于一个想到我还没有物理删除v4包，删除之后项目运行正常。
根本原因
V4包版本太低，ActivityCompat类没有requestPermissions方法
解决办法
依赖删除掉，并且需要物理删除离线的android-support-v4.jar包
尊重原创，转载请注明出处： http://blog.csdn.net/qq137722697
