The role of Android:context

Context, the activity in which we use this instead, and to a button of the onclick (view view) and other methods, we use this when the error, The main reason to switch to Activityname.this is because the class that implements the context has several models specific to Android, Activity, service, and Broadcastreceiver.

Some methods in the main function can be used normally, but to get other class calls on the null pointer, you can guess is not the context caused.

The role of Android:context