单击菜单中的按钮后如何切换到使用数据绑定的片段

Question

在此处输入图像描述

在此处输入图像描述

类MainActivity:AppCompatActivity（）{lateinit var binding:ActivityMainBinding重写fun onCreate（savedInstanceState:Bundle？）{super.onCreate（savedInstanceState）binding=ActivityMainBinding.inflate（layoutInflater）setContentView（binding.root）}

override fun onCreateOptionsMenu(menu: Menu?): Boolean {
    menuInflater.inflate(R.menu.bottom_nav_bar_main , menu)
    return true
}

override fun onOptionsItemSelected(item: MenuItem): Boolean {
    val intent : Intent
    when(item.itemId) {
        R.id.itemCourses -> {
            val fragment = CoursesFragment.newInstance()
        }
    }
    return true
}

}

类课程片段：片段（）{

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
    val binding = FragmentCoursesBinding.inflate(inflater , container , false)
    return binding.root
}

}

Answer 1

步骤1：将FragmentContainerView添加到活动xml

<androidx.fragment.app.FragmentContainerView
     android:id="@+id/container"
     android:layout_width="match_parent"
     android:layout_height="match_parent" />

第二步：在你的主要活动中。类文件，声明FragmentManager

private FragmentManager manager;

第3步：在onCreate（）中初始化FragmentManager

manager = getSupportFragmentManager();

第4步：在您的onOptionsItemSelected中开始此片段

Bundle bundle = new Bundle();
manager.beginTransaction()
                .replace(R.id.container, YourFragment.class, bundle, "TAG")
                .setReorderingAllowed(true)
                //.setCustomAnimations(R.anim.anim_enter, R.anim.anim_exit)
                .addToBackStack("TAG")
                .commit();