绑定不适用于与 ViewStub 关联的片段

Question

我遇到了当前的问题。现在我正在尝试懒惰地膨胀一堆片段以获得更好的性能，它们是 ViewPager 的一部分。我找到的唯一解决方案是使用 ViewStub。这是我到目前为止所做的：

abstract class ViewStubFragment: BaseFragment() {

    private lateinit var binding: FragmentViewStubBinding

    private var mSavedInstanceState: Bundle? = null
    private var hasInflated = false
    private var viewStub: ViewStub? = null
    private var visible = false

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        binding = FragmentViewStubBinding.inflate(inflater, container, false)

        viewStub = binding.fragmentViewStub.viewStub
        viewStub?.layoutResource = getViewStubLayoutResource()
        mSavedInstanceState = savedInstanceState

        if(visible && !hasInflated) {
            val inflatedView = viewStub?.inflate()
            if (inflatedView != null) {
                onCreateViewAfterViewStubInflated(inflatedView, mSavedInstanceState)
            }
        }

        return binding.root
    }

    protected abstract fun onCreateViewAfterViewStubInflated(
        inflatedView: View,
        savedInstanceState: Bundle?
    )

    @LayoutRes
    protected abstract fun getViewStubLayoutResource(): Int


    @CallSuper
    protected fun afterViewStubInflated(originalViewContainerWithViewStub: View?) {
        hasInflated = true
        if (originalViewContainerWithViewStub != null) {
            val progressBar = binding.progressBar
            progressBar.visibility = View.GONE
        }
    }

    override fun onResume() {
        super.onResume()

        visible = true
        if (viewStub != null && !hasInflated) {
            val inflatedView = viewStub!!.inflate()
            onCreateViewAfterViewStubInflated(inflatedView, mSavedInstanceState)
            afterViewStubInflated(view)
        }
    }

对应布局：

<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <ProgressBar
            android:id="@+id/progress_bar"
            android:foregroundGravity="center"
            android:layout_gravity="center"
            android:indeterminate="true"
            android:layout_width="48dp"
            android:layout_height="48dp"/>
        <ViewStub
            android:id="@+id/fragment_view_stub"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>

    </FrameLayout>

</layout>

我正在尝试延迟膨胀的 HomeFragment 的部分代码：

class HomeFragment : ViewStubFragment() {

    lateinit var binding: FragmentHomeBinding

........

    override fun onCreateViewAfterViewStubInflated(
        inflatedView: View,
        savedInstanceState: Bundle?
    ) {
        setDataBinding()
        observeLiveData()
    }

    override fun getViewStubLayoutResource(): Int {
        binding = FragmentHomeBinding.inflate(layoutInflater)
        return binding.root.sourceLayoutResId
    }

问题是当 setDataBinding() 被调用时，由于某种原因没有应用绑定，因此像 RecyclerView 这样的视图没有显示在屏幕上或者点击事件不工作。我已经搜索了几个小时，但找不到与此问题相关的解决方案。

Answer 1

经过一个小时的努力，我找到了一个解决方案，不确定它是否是最好的。

        if(visible && !hasInflated) {
            inflatedViewBinding = binding.fragmentViewStub.binding
            val inflatedView = viewStub?.inflate()
            if (inflatedView != null) {
                onCreateViewAfterViewStubInflated(inflatedView, mSavedInstanceState, inflatedViewBinding)
            }
        }

我将存储在 ViewStubProxy 中的绑定（与膨胀布局关联）作为 onCreateViewAfterViewStubInflated() 中的参数传递，然后将 HomeFragment 绑定分配给它。

    override fun onCreateViewAfterViewStubInflated(
        inflatedView: View,
        savedInstanceState: Bundle?,
        binding: ViewDataBinding?
    ) {
        this.binding = binding as FragmentHomeBinding
        .......
    }

绑定不适用于与 ViewStub 关联的片段

Binding is not applying to a fragments associated with ViewStub

data-binding

android

viewstub

kotlin

android-viewpager2