Fragment的用法

package wangaimin.bwie.com.example.lenovo.monizhoukao3;import android.os.Bundle;import android.support.annotation.IdRes;import android.support.v4.widget.DrawerLayout;import android.support.v7.app.AppCompatActivity;import android.widget.ArrayAdapter;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.RadioGroup;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity {    private DrawerLayout drawerlayout;    private LinearLayout linearlayout;    private ListView listview;    private List<String> list;    private RadioGroup radiogroup;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        drawerlayout = (DrawerLayout) findViewById(R.id.drawerlayout);        linearlayout = (LinearLayout) findViewById(R.id.linearlayout);        listview = (ListView) findViewById(R.id.listview);        radiogroup = (RadioGroup) findViewById(R.id.radiogroup);        list = new ArrayList<>();        list.add("钱包");        list.add("行程记录");        list.add("好友邀请");        list.add("设置");        ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, list);        listview.setAdapter(adapter);        getSupportFragmentManager().beginTransaction().replace(R.id.framelayout,new Fragment_01()).commit();        radiogroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {            @Override            public void onCheckedChanged(RadioGroup radioGroup, @IdRes int i) {                switch (i){                  case R.id.btn01:                    getSupportFragmentManager().beginTransaction().replace(R.id.framelayout,new Fragment_01()).commit();                      break;                    case R.id.btn02:                        getSupportFragmentManager().beginTransaction().replace(R.id.framelayout,new Fragment_02()).commit();                        break;                    case R.id.btn03:                        getSupportFragmentManager().beginTransaction().replace(R.id.framelayout,new Fragment_03()).commit();                        break;                    case R.id.btn04:                        getSupportFragmentManager().beginTransaction().replace(R.id.framelayout,new Fragment_04()).commit();                        break;                }            }        });    }}