由于ViewPager2类是最近才开发的,因此没有太多文档可以显示正确的用法。我正在查看给出的示例 https://developer.android.com/guide/navigation/navigation-swipe-view-2 但无法弄清楚如何将CollectionDemoFragment连接到Main Activity。需要帮助。谢谢。
这是使用ViewPager2和TabLayout创建片段的示例代码
class CollectionDemoFragment : Fragment() {
// When requested, this adapter returns a DemoObjectFragment,
// representing an object in the collection.
private lateinit var demoCollectionAdapter: DemoCollectionAdapter
private lateinit var viewPager: ViewPager2
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return inflater.inflate(R.layout.collection_demo, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
demoCollectionAdapter = DemoCollectionAdapter(this)
viewPager = view.findViewById(R.id.pager)
viewPager.adapter = demoCollectionAdapter
}
}
class DemoCollectionAdapter(fragment: Fragment) : FragmentStateAdapter(fragment) {
override fun getItemCount(): Int = 100
override fun createFragment(position: Int): Fragment {
// Return a NEW fragment instance in createFragment(int)
val fragment = DemoObjectFragment()
fragment.arguments = Bundle().apply {
// Our object is just an integer :-P
putInt(ARG_OBJECT, position + 1)
}
return fragment
}
}
private const val ARG_OBJECT = "object"
// Instances of this class are fragments representing a single
// object in our collection.
class DemoObjectFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
return inflater.inflate(R.layout.fragment_collection_object, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
arguments?.takeIf { it.containsKey(ARG_OBJECT) }?.apply {
val textView: TextView = view.findViewById(android.R.id.text1)
textView.text = getInt(ARG_OBJECT).toString()
}
}
}
我有一个MainActivity作为
class MainActivity : AppCompatActivity() {
private lateinit var viewPager: ViewPager2
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
}
}