Main

public class MainActivity extends AppCompatActivity {    private DrawerLayout drawer;    private LinearLayout menu;    private ListView lv;    private FrameLayout fl;    private RadioGroup rg;    List<String> tabs=new ArrayList<>();    private ImageView img;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        tabs.add("个人设置");        tabs.add("缓存");        tabs.add("夜间模式");        tabs.add("配置");        drawer = (DrawerLayout) findViewById(R.id.drawer);        menu = (LinearLayout) findViewById(R.id.menu);        img = (ImageView) findViewById(R.id.img);        img.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                drawer.closeDrawer(menu);            }        });        getSupportFragmentManager().beginTransaction().replace(R.id.fl,new Fragment01()).commit();        rg = (RadioGroup) findViewById(R.id.rg);        rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {            @Override            public void onCheckedChanged(RadioGroup radioGroup, @IdRes int i) {                switch (i) {                    case R.id.btn1:                        getSupportFragmentManager().beginTransaction().replace(R.id.fl, new Fragment01()).commit();                        break;                    case R.id.btn2:                        getSupportFragmentManager().beginTransaction().replace(R.id.fl, new fragment02()).commit();                        break;                }            }        });    }