我希望在单击Button时使用带有Databinding的ViewModel来禁用复选框,但是除非片段被销毁和重新创建,否则UI不会更新。
似乎有许多类似的问题,但那些最相似的问题似乎都是通过设置binding.lifecycleOwner来解决的,我已经这样做了。
fragment_checkbox_databinding.xml:
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:context=".CheckboxDatabindingFragment">
<data>
<variable
name="viewModel"
type=".CheckboxDatabindingFragmentViewModel" />
</data>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<CheckBox
android:id="@+id/my_checkbox"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:enabled="@{viewModel.checkboxEnabled}" />
<Button
android:id="@+id/my_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@{() -> viewModel.startClicked()}" />
</LinearLayout>
</layout>CheckboxDatabindingFragment.kt:
class CheckboxDatabindingFragment() : Fragment() {
private lateinit var viewModel: CheckboxDatabindingFragmentViewModel
private var _binding: FragmentCheckboxDatabindingBinding? = null
private val binding get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View {
viewModel = ViewModelProvider(this).get(CheckboxDatabindingFragmentViewModel::class.java )
_binding = FragmentCheckboxDatabindingBinding.inflate(inflater, container, false)
binding.lifecycleOwner = viewLifecycleOwner // androidx.fragment.app.FragmentViewLifecycleOwner
binding.viewModel = viewModel
return binding.root
}
...
}CheckboxDatabindingFragmentViewModel.kt:
class CheckboxDatabindingFragmentViewModel(application: Application) : AndroidViewModel(application) {
var checkboxEnabled = true
fun startClicked() {
checkboxEnabled = false
}
}我知道我可以通过手动获取CheckboxDatabindingFragment.kt中的复选框视图并设置isEnabled属性来轻松地实现这个功能,但这违背了DataBinding的目的。
我需要片段,而不是活动,作为所有者,所以我如何才能让片段UI更新呢?
https://stackoverflow.com/questions/69484485
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