Android Studio中的BottomNavigation

Question

I tried to write some codes in Android Studio, and then suddenly Android Studio stopped recognizing BottomNavigation .

Here is my code:

package com.example.edward.crmanager;

import android.os.Bundle; import android.support.annotation.NonNull; 
import android.support.design.widget.BottomNavigationView; 
import android.support.v7.app.AppCompatActivity; 
import android.view.MenuItem; import android.widget.TextView;

public class Navigation_Stats extends AppCompatActivity {

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

        BottomNavigationView bottomNav = findViewById(R.id.bottom_navigation);
    } 
}

Answer 1

您是否更改了gradle中的任何依赖关系？