Attempt to invoke virtual method 'java.lang.Object android.content.Context.getSystemService(java.lang.String)

for make sure when return back & continuing previous activity i just Added & checking for getContext()!=null

Here's an good example :

Before block

adapter = new ExampleAdapter(getContext());
adapter.setData(items);
listView.setAdapter(adapter);

And better replace for getActivity()!=null

For example:

if (getActivity()!=null){
    adapter = new ExampleAdapter(getActivity());
    adapter.setData(items);
    listView.setAdapter(adapter);
}

I think this is solved all problem which got the same error like my problems !

Be conscious of where in the lifecycle you are. The value of getContext() may not be available yet.

For example, in a DialogFragment, the context will not be available until onCreateDialog() is called. So don't try and create an adapter in the constructor, because the context will still be null at that point.