Android context Null pointer exception

The code in the fragment context is null

public class Placeholderfragment extends Fragment{context Context = Getactivity ();}

This defines the context as null. Of course, my actual code is not written like this, but this means. It is assumed that the activity will not be empty. In fragment, it is null.

Code context in activity is not NULL

public class Mainactivity extends Fragmentactivity {context context = this;}

The following way to get the context throws an exception

public class Mainactivity extends Fragmentactivity {Context context = getapplicationcontext ();;}

The above is just a matter of defining a single variable, and if the activity you write to the OnCreate method is certainly possible.

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Android context Null pointer exception