问题描述
我正在研究Kotlin,并且对recyclerview感到困惑。 任务很简单:显示片段中单击的回收者(内部活动)项目中的数据。
模型:
data class MyModel (
val info1:String,val info2:String,val info3:String)
recyclerView
是使用我在Antonio的书中(Android开发人员的Kotlin)所看到的想法实现的-不使用 intarface :
class RecyclerAdapter(
val myList:List<MyModel>,val listener:(MyModel)->Unit):RecyclerView.Adapter<RecyclerAdapter.MyViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup,viewType: Int): MyViewHolder {
val itemViewholder = LayoutInflater.from(parent.context).inflate(R.layout.recycler_item,parent,false)
return MyViewHolder(itemViewholder)
}
override fun onBindViewHolder(holder: MyViewHolder,position: Int) {
holder.bind(myList[position],listener)
}
override fun getItemCount(): Int {
return myList.count()
}
class MyViewHolder(itemView:View):RecyclerView.ViewHolder(itemView){
fun bind(list:MyModel,itemListener: (MyModel) -> Unit) = with(itemView){
recycler_infor1.text = list.info1
recicler_infor2.text = list.info2
setonClickListener { itemListener(list) }
}
}}
活动中:
with(my_recyclerView){
layoutManager = linearlayoutmanager(this@MainActivity,RecyclerView.VERTICAL,false)
setHasFixedSize(true)
adapter = RecyclerAdapter(fakeItens()){
supportFragmentManager.commit {
replace(R.id.fragment_container,FragmentDetail()).addToBackStack(null)
}
}
}
运行该应用程序时,recyclerView
还会在每个项目中显示第一和第二信息。
现在,我需要在具有三个textView
的Fragment中显示这些信息和第三个信息:
android:id="@+id/frag_infor1"
android:id="@+id/frag_infor2"
android:id="@+id/frag_infor3"
我该怎么做?
解决方法
感谢null_override,我找到了解决方案:
1-使MyModel
Parcelable
data class MyModel(val info1:String?,val info2:String?,val info3:String?
):Parcelable {
constructor(parcel: Parcel) : this(
parcel.readString(),parcel.readString(),parcel.readString()
)
override fun writeToParcel(parcel: Parcel,flags: Int) {
parcel.writeString(info1)
parcel.writeString(info2)
parcel.writeString(info3)
}
override fun describeContents(): Int {
return 0
}
companion object CREATOR : Parcelable.Creator<MyModel> {
override fun createFromParcel(parcel: Parcel): MyModel {
return MyModel(parcel)
}
override fun newArray(size: Int): Array<MyModel?> {
return arrayOfNulls(size)
}
}
}
2-传递给bundle
并在两者中都使用Fragment
将参数设置为apply
with(my_recyclerView){
layoutManager = LinearLayoutManager(this@MainActivity,RecyclerView.VERTICAL,false)
setHasFixedSize(true)
adapter = RecyclerAdapter(fakeItens()){
val bundle = Bundle().apply { putParcelable("Key",it) }
supportFragmentManager.commit {
replace(R.id.fragment_container,FragmentDetail().apply { arguments = bundle }).addToBackStack(null)
}
}
}
3-在Fragment
lateinit var data:MyModel
override fun onAttach(context: Context) {
super.onAttach(context)
arguments?.getParcelable<MyModel>("Key").let {
if (it != null) {
data = it
}
}
}
4-绑定views
override fun onViewCreated(view: View,savedInstanceState: Bundle?) {
super.onViewCreated(view,savedInstanceState)
frag_infor1.text = data.info1
frag_infor2.text = data.info2
frag_infor3.text = data.info3
}