Android 片段中的参数仍然为null
我试图通过一个包将两个字符串传递给我的另一个片段。问题是,onCreate中的参数仍然为空。这是我的密码:Android 片段中的参数仍然为null,android,android-fragments,kotlin,android-bundle,Android,Android Fragments,Kotlin,Android Bundle,我试图通过一个包将两个字符串传递给我的另一个片段。问题是,onCreate中的参数仍然为空。这是我的密码: class VenueDetailFragment : Fragment() { private lateinit var venueId: String private lateinit var venueName: String companion object { fun newInstance(venue: Venue): VenueDetailFragment {
class VenueDetailFragment : Fragment() {
private lateinit var venueId: String
private lateinit var venueName: String
companion object {
fun newInstance(venue: Venue): VenueDetailFragment {
val frag = VenueDetailFragment()
val bundle = Bundle()
bundle.putString(Extra.VENUE_ID_KEY, venue.id)
bundle.putString(Extra.VENUE_NAME, venue.name)
frag.arguments = bundle
return VenueDetailFragment()
}
}
private lateinit var viewModel: VenueDetailViewModel
override fun onAttach(context: Context) {
super.onAttach(context)
viewModel = ViewModelProviders.of(this).get(VenueDetailViewModel::class.java)
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
arguments?.let {
venueId = it.getString(Extra.VENUE_ID_KEY, "0")
venueName = it.getString(Extra.VENUE_NAME, getString(R.string.venue_detail_title_unknown))
}
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? =
inflater.inflate(R.layout.venue_detail_fragment, container, false)
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
viewModel.getVenueDetails(venueId).observe(this, Observer { result ->
result?.let { safeVenue ->
venueDetailTitle.text =
if (safeVenue.name.isNotEmpty()) safeVenue.name else venueName
venueDetailDescription.text =
if (safeVenue.description.isNotEmpty()) safeVenue.description
else getString(R.string.venue_detail_description_unknown)
venueDetailAddress.text = safeVenue.location.formattedAddress.joinToString(",\n")
venueDetailRatingBar.rating = (safeVenue.rating / 5).toFloat()
setupContactView(safeVenue.contact)
}
})
}
private fun setupContactView(contact: Contact) {
venueDetailTwitterBtn.visibility = getVisibility(contact.twitter)
venueDetailInstagramBtn.visibility = getVisibility(contact.instagram)
venueDetailFacebookBtn.visibility = getVisibility(contact.facebook)
venueDetailCallBtn.visibility = getVisibility(contact.phone)
}
private fun getVisibility(contactType: String?): Int {
return if (contactType.isNullOrEmpty()) View.VISIBLE else View.GONE
}
}
我通过以下方式初始化新片段:
private fun navigateToDetailPage(data: List<Venue>) {
activity?.let { safeActivity ->
venueResultList.adapter = VenueFinderAdapter(
safeActivity, data,
object : VenueFinderAdapter.VenueSelectionListener {
override fun onVenueSelected(venue: Venue) {
safeActivity.supportFragmentManager.beginTransaction().apply {
replace(R.id.fragmentContainer, VenueDetailFragment.newInstance(venue))
addToBackStack(null)
commit()
}
}
})
}
}
private fun navigateToDetailPage(数据:列表){
活动?.let{safeActivity->
venueResultList.adapter=VenueFinderAdapter(
安全活动、数据、,
对象:VenueFinderAdapter.VenueSelectionListener{
已选定的地点(地点:地点){
safeActivity.supportFragmentManager.beginTransaction().apply{
替换(R.id.fragmentContainer,VenueDetailFragment.newInstance(场地))
addToBackStack(空)
提交()
}
}
})
}
}
如果我运行此命令,我的两个lateinit变量(字符串)在onViewCreated中仍然为null。我看到另一篇帖子告诉我应该从onCreate中的参数中获取值,正如你所看到的,我也尝试过,但没有成功
有人能告诉我我做错了什么吗?您正在返回
VenueDetailFragment()
,您应该返回frag
fun newInstance(venue: Venue): VenueDetailFragment {
val frag = VenueDetailFragment()
val bundle = Bundle()
bundle.putString(Extra.VENUE_ID_KEY, venue.id)
bundle.putString(Extra.VENUE_NAME, venue.name)
frag.arguments = bundle
return frag
}
您正在返回
VenueDetailFragment()
,您应该返回frag
fun newInstance(venue: Venue): VenueDetailFragment {
val frag = VenueDetailFragment()
val bundle = Bundle()
bundle.putString(Extra.VENUE_ID_KEY, venue.id)
bundle.putString(Extra.VENUE_NAME, venue.name)
frag.arguments = bundle
return frag
}
在newInstance方法中返回frag而不是VenueDetailFragment()
fun newInstance(venue: Venue): VenueDetailFragment {
val frag = VenueDetailFragment()
val bundle = Bundle()
bundle.putString(Extra.VENUE_ID_KEY, venue.id)
bundle.putString(Extra.VENUE_NAME, venue.name)
frag.arguments = bundle
return frag
}
在newInstance方法中返回frag而不是VenueDetailFragment()
fun newInstance(venue: Venue): VenueDetailFragment {
val frag = VenueDetailFragment()
val bundle = Bundle()
bundle.putString(Extra.VENUE_ID_KEY, venue.id)
bundle.putString(Extra.VENUE_NAME, venue.name)
frag.arguments = bundle
return frag
}
哇,我能把我的30分钟拿回来吗?谢谢道沃,我能把我的30分钟拿回来吗?谢谢D