BottomNavigationView-activity

package com.tistory.firewallgogo.ex56bottomnaviagtionview;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.MenuItem;
import com.google.android.material.bottomnavigation.BottomNavigationView;

public class MainActivity extends AppCompatActivity {

BottomNavigationView bottomNavigationView;

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

bottomNavigationView = findViewById(R.id.bnv);
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {

//원래는 아이템을 클릭할때마다 프레그먼트를 바꾸는게 일반적입니다.
switch (item.getItemId()){
case R.id.bnv_aa:
findViewById(R.id.layout_content).setBackgroundColor(Color.BLUE);
break;
case R.id.bnv_bb:
findViewById(R.id.layout_content).setBackgroundColor(Color.GRAY);
break;
case R.id.bnv_cc:
findViewById(R.id.layout_content).setBackgroundColor(Color.WHITE);
break;
case R.id.bnv_dd:
findViewById(R.id.layout_content).setBackgroundColor(Color.RED);
break;
}
return true;//reture값이 true가 아니면 작동하지 않습니다.
}
});
}
}