Cannot find symbol method FindViewById(int) with extends AppCompatActivity

Question

I'm trying to assign a button to a Button variable using FindViewById like this:

Button dotBtn = (Button)FindViewById(R.id.dotBtn);

I get an error

Cannot find symbol method FindViewById(int)

What is the problem? Does it have something to do with the extends AppCompatActivity? I mean with this:

public class MainActivity extends AppCompatActivity

Answer 1

It should be findViewById not FindViewById . Small f

Answer 2

试试这个按钮dotBtn =（Button）findViewById（R.id.dotBtn）;

Answer 3

It has nothing to do with AppCompatActivity. Actually it has to be : "findViewById" with small 'f' and not Capital 'F'.