Android 第十四章 FragmentContainerView

1. FragmentContainerView extends FrameLayout
2. FragmentContainerView是专门为Fragments设计的自定义布局。它扩展了FrameLayout，因此它可以可靠地处理Fragment 事务，并且它还具有与Fragment 行为协调的附加特性
3. FragmentContainerView应用作Fragments的容器，通常设置在活动的xml布局
4. FragmentContainerView将只允许Fragment的Fragment.onCreateView返回的视图。尝试添加任何其他视图将导致IllegalStateException
5. 对于17以上的api，FragmentContainerView禁用布局动画和转换。否则，应通过FragmentTransaction.setCustomAnimations完成动画。如果animateLayoutChanges设置为true或直接调用setLayoutTransition，则将引发UnsupportedOperationException
6. 使用退出动画的Fragment 在FragmentContainerView的所有其他Fragment 之前绘制。这样可以确保退出的Fragment 不会出现在视图的顶部。

public class MainActivity extends AppCompatActivity {    private Button btn_First, btn_Second;    private FragmentTransaction fragmentTransaction;    private FirstFragment firstFragment = null;    private SecondFragment secondFragment = null;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();        initData();        initClick();        initFragment();    }    private void initView() {        btn_First = findViewById(R.id.btn_First);        btn_Second = findViewById(R.id.btn_Second);    }    private void initData() {    }    private void initClick() {        btn_First.setOnClickListener(v -> {            showFragment(firstFragment);        });        btn_Second.setOnClickListener(v -> {            showFragment(secondFragment);        });    }    private void initFragment() {        fragmentTransaction = getSupportFragmentManager().beginTransaction();        firstFragment = new FirstFragment();        fragmentTransaction.add(R.id.fcv, firstFragment);        secondFragment = new SecondFragment();        fragmentTransaction.add(R.id.fcv, secondFragment);        fragmentTransaction.commit();        showFragment(firstFragment);    }    private void hideFragment() {        if (null != firstFragment) {            fragmentTransaction.hide(firstFragment);        }        if (null != secondFragment) {            fragmentTransaction.hide(secondFragment);        }    }    private void showFragment(Fragment fragment) {        if (null != fragment) {            fragmentTransaction = getSupportFragmentManager().beginTransaction();            hideFragment();            fragmentTransaction.show(fragment);            fragmentTransaction.commit();        }    }}

来源地址：https://blog.csdn.net/weixin_43969550/article/details/127880837