Answer 1

Try this: So I deleted the "setContentView" in the on click method and I added a space before the "findViewById". If this doesn't work please show me the copy of your xml file

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

}
public void onButtonClick(View v){

TextView t2 = (TextView) findViewById(R.id.textView2);
t2.setText("LITTERALLY ANYTHING");
}

}

Answer 2

OK perfect then