Question

我已将FragmentStatePageAdapter设置为在相同布局和不同数据（用户配置文件）的片段之间滑动。当我给它列出2个项目时，一切都很好。如果我给它3个或更多项目，它将创建片段视图，但是在第三次滑动内容上，无论我向哪个方向滑动（向前，向前，向前，向后），都变成空白。如果在仍然按住屏幕的情况下准确地滑动到第三项，我可以看到它的有效内容，但是当我完成滑动释放时，所有屏幕都消失了。

页面适配器的设置如下。（swipeList是用户ID的列表，swipeEntityType == 0，每个用户内容由通过捆绑传递的“ uid”加载）

class SwipePagerFragment : Fragment() {

    private lateinit var parent: MainActivity
    private lateinit var state: State
    private lateinit var ctx: Context
    private lateinit var swipeList: MutableList<Int>
    private lateinit var pager: ViewPager

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {

        val view = inflater.inflate(R.layout.fragment_swipe_pager, container, false)

        parent = activity as MainActivity
        state = parent.state
        ctx = state.ctx
        swipeList = state.swipeList

        pager = view.findViewById(R.id.fragmentSwipePager_pager)
        val pagerAdapter = ScreenSlidePagerAdapter(childFragmentManager)
        pager.adapter = pagerAdapter

        return view
    }

    private inner class ScreenSlidePagerAdapter(fm: FragmentManager) : FragmentStatePagerAdapter(fm) {
        override fun getCount(): Int = swipeList.size

        override fun getItem(position: Int): Fragment = when (state.swipeEntityType) {
            0 -> {
                makeUserFragment(swipeList[position])
            }
            else -> {
                makeEventFragment(swipeList[position])
            }
        }
    }

    private fun makeUserFragment(uid: Int): UserFragment {
        val bundle = Bundle()
        bundle.putInt("uid", uid)
        val frag = UserFragment()
        frag.arguments = bundle
        return frag
    }

    private fun makeEventFragment(eid: Int): EventFragment {
        val bundle = Bundle()
        bundle.putInt("eid", eid)
        val frag = EventFragment()
        frag.arguments = bundle
        return frag
    }

}

Answer 1

设置

pager.offscreenPageLimit = swipeList.size

解决了我的问题

如果Kotlin FragmentStatePageAdapter具有超过2个项目，则在第三次滑动时销毁视图

1 个答案: