Fragment——向Activity中动态加载Fragment

public class MainActivity extends AppCompatActivity implements RadioGroup.OnCheckedChangeListener,Fragment.onButtonClickedListener{

private Button btn_add = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

btn_add = (Button) findViewById(R.id.btn_add);
btn_add.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//实例化要加载的Fragment
Fragment fragment = new Fragment();
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
//将fragment添加到Activity
fragmentTransaction.add(R.id.fragmentView,fragment,"fragmentTest");
//将事物提交给Activity
fragmentTransaction.commit();
}
});
}
}

public class Fragment extends android.app.Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment, container, false);
return view;
}
}