在Android中使用setVisibility？

Question

According to android docs, void setVisibility(int visibility) has One the following parameters VISIBLE , INVISIBLE , or GONE .

View dp2 = findViewByid(R.id.title);
dp2.setVisibility(View.GONE);

So why do we have to use View.GONE , instead of dp2.setVisibility(GONE);

Answer 1

GONE is a static field on the View class.

If your code has import android.view.View , you reference GONE as View.GONE .

If your code has import static android.view.View.GONE — a static import — you can reference GONE simply as GONE .

Answer 2

如果你是在扩展视图或类extends任何类extends View ，然后就可以直接使用GONE不使用View.GONE ，但如果你是在一个类中，不扩展任何View ，那么你必须使用View.GONE ，这是因为GONE是在类View定义的常量