Viewpager2 Android：视图上的“下一步”按钮会在右侧生成两张幻灯片

Question

我在Android上遇到viewpager2问题。我有一个viewpager2根据位置创建一些片段。每个片段都有一个下一个按钮，可在视图寻呼机中水平导航。

但是当我从按钮要求下一页时，我有滑动两次的动作。由于片段边界的预加载，就像调用适配器的createFragment方法两次一样。 >

管理视图寻呼机的活动：

class ConfigurationActivity : AppCompatActivity() {
    private var viewPager : ViewPager2? = null


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_configuration)

        viewPager = viewPager2
        val instance = this

        viewPager!!.apply {
            isUserInputEnabled = true
            orientation = ViewPager2.ORIENTATION_HORIZONTAL

            if(viewPager!!.adapter == null)
                viewPager!!.adapter = ConfigAdapter(supportFragmentManager, lifecycle, instance, 2)
        }

        viewPager!!.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
            override fun onPageSelected(position: Int) {
                super.onPageSelected(position)          
                currentItem = position
            }
        })
    }

    companion object{
        private var currentItem : Int = 0

        fun nextPage(instance : ConfigurationActivity, currentPosition : Int?){
            instance.viewPager!!.currentItem = currentItem + 1
        }
    }
}
The FragmentStateAdapter

class ConfigAdapter(fm: FragmentManager, lc : Lifecycle, private val instance : ConfigurationActivity, configSnapshot : ArrayList<Configuration>) : FragmentStateAdapter(fm, lc) {
    private val configSize = configSnapshot.size

    override fun getItemCount(): Int {
        val length = configSize + 3
        instance.pageIndicatorView.count = length
        return length
    }

    override fun createFragment(position: Int): Fragment {
        Timber.d("creating fragment at position $position")
        return when(position){
                0 -> WelcomeFragment(instance)
                in 1..configSize /* position between 1 and configSize (included) */ -> ConfigureFragment(instance, position-1)
                1 + configSize -> IdentifyFragment(instance)
                2 + configSize -> EndFragment()
                else -> Fragment()
            }
    }
}
一个片段示例：

class ConfigureFragment(private val instance : ConfigurationActivity, private val configPosition: Int) : Fragment() {
...
   view.button_continue.setOnClickListener {
       nextPage(instance, configPosition+1)
   }
...
}

我在Android上遇到viewpager2问题。我有一个viewpager2根据位置创建一些片段。每个片段都有一个下一个按钮，可在视图寻呼机中水平导航。但是当...

Answer 1

以这种方式尝试：-