Contextcompat. Checkselfpermission() method

ContextCompat Class checkSelfPermission Method is used to detect whether a user has authorized a certain permission .

checkSelfPermission() Method needs to pass two parameters , The first parameter needs to be passed in Context, The second parameter needs to pass in the permission to be detected , Such as the authority to make calls :Manifest.permission.CALL_PHONE. The return value of the method is -1（PackageManager.PERMISSION_DENIED） perhaps 0（PackageManager.PERMISSION_GRANTED）. If the return value is GRANTED Is authorized , Otherwise, you need to apply for authorization .

example ：

ContextCompat.checkSelfPermission(MainActivity.this,
    Manifest.permission.CALL_PHONE) = PackageManager.PERMISSION_GRANTED	// If equal, it is authorized 

It is important to note that in AS Inside, choose Manifest Then click Alt+Enter, Two prompts will appear , One is to introduce Manifest(java.util.jar), The other is to introduce Manifest(android), Need here import Yes. Manifest(android) My bag , Otherwise, it will report a mistake ：cannot resolve 'permission'