【发布时间】：2021-07-21 07:24:28
【问题描述】：
在从服务器获取数据后，我试图在嵌套的 recyclerview 中显示数据，例如 play store。我已成功检索并解析父 recyclerview 的 title，但无法显示作为子布局的水平 recyclerview。
在视图模型实例化时，CategortAdapter.kt 出现错误，它在下一行的ViewModelProvider(context) 下显示红线：
val viewModel = ViewModelProvider(context).get(CatImagesViewModel::class.java)
以下是我的 JSON 响应：
{
"status": "200",
"message": "Success",
"result": [
{
"_id": "60f516fa846e059e2f19c50c",
"category": "Shirts",
"sku": [
{
"name": "Oxford shirt",
"brand": "John players",
"price": "25",
"color": "Blue",
"img": "https://firebasestorage.googleapis.com/v0/b/koovs-1ff31.appspot.com/o/shi1.jpg?alt=media&token=64779194-e3b5-484f-a610-c9a20648b64c"
},
{
"name": "Buttoned down",
"brand": "Gap originals",
"price": "45",
"color": "Pink",
"img": "https://firebasestorage.googleapis.com/v0/b/koovs-1ff31.appspot.com/o/shi2.jpg?alt=media&token=0b207b90-f1bc-4771-b877-809648e6bdc1"
},
{
"name": "Collared",
"brand": "Arrow",
"price": "30",
"color": "White",
"img": "https://firebasestorage.googleapis.com/v0/b/koovs-1ff31.appspot.com/o/shi3.jpg?alt=media&token=2c1bb3f8-e739-4f09-acbc-aa11fed795e3"
},
{
"name": "Printed",
"brand": "John players",
"price": "30",
"color": "Olive green",
"img": "https://firebasestorage.googleapis.com/v0/b/koovs-1ff31.appspot.com/o/shi4.jpg?alt=media&token=666f94bf-4769-44fe-a909-3c81ca9262f7"
},
{
"name": "Hoodie",
"brand": "Levis",
"price": "44",
"color": "Yellow",
"img": "https://firebasestorage.googleapis.com/v0/b/koovs-1ff31.appspot.com/o/shi5.jpg?alt=media&token=65fccef4-a882-4278-b5df-f00eb2785bf1"
}
]
},
{
"_id": "60f51c37846e059e2f19c50f",
"category": "Shoes",
"sku": [
{
"name": "Sneakers",
"brand": "Puma",
"price": "35",
"color": "Black and white",
"img": "https://firebasestorage.googleapis.com/v0/b/koovs-1ff31.appspot.com/o/sho1.jpg?alt=media&token=d078988d-9e85-4313-bb4a-c9d46e09f0b9"
},
{
"name": "Running shoe",
"brand": "Nike",
"price": "99",
"color": "Multicolor",
"img": "https://firebasestorage.googleapis.com/v0/b/koovs-1ff31.appspot.com/o/sho2.jpg?alt=media&token=ed2e7387-3cf6-44df-9f7d-69843eb0bcdf"
},
{
"name": "Yezzy",
"brand": "Adidas",
"price": "349",
"color": "Gray",
"img": "https://firebasestorage.googleapis.com/v0/b/koovs-1ff31.appspot.com/o/sho3.jpg?alt=media&token=2c37ef76-37bb-4bdd-b36c-dea32857291f"
},
{
"name": "Sneakers",
"brand": "Puma",
"price": "79",
"color": "Black",
"img": "https://firebasestorage.googleapis.com/v0/b/koovs-1ff31.appspot.com/o/sho4.jpg?alt=media&token=4acd763e-8b93-47cd-ba45-92f34af4cf83"
},
{
"name": "Joyride running",
"brand": "Nike",
"price": "80",
"color": "White",
"img": "https://firebasestorage.googleapis.com/v0/b/koovs-1ff31.appspot.com/o/sho5.jpg?alt=media&token=e3780dcc-52cb-49d5-9791-e0a44870716c"
}
]
}
]
}
在垂直的父回收器视图中，我想在 JSON 响应中显示标题 category，在水平回收器视图中显示 sku。
在子回收站视图中，我只想显示 sku 数组下的图像。
下面是我的代码：
ApiService.kt
interface ApiService {
@GET("getProducts")
suspend fun getCategories(): Response<Product>
@GET("getProducts")
suspend fun getCatImg(): Response<Product>
}
Product.kt
data class Product(
val message: String,
val result: List<Result>,
val status: String
)
Result.kt
data class Result(
val _id: String,
val category: String,
val sku: List<Sku>
)
Sku.kt
data class Sku(
val brand: String,
val color: String,
val img: String,
val name: String,
val price: String
)
parent_row.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="12dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/catTitle"
android:textStyle="bold"
android:textSize="18sp"
android:textColor="#345"/>
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/childRecycler"
android:layout_below="@+id/catTitle"
android:layout_marginTop="8dp"/>
</RelativeLayout>
child_row.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<androidx.cardview.widget.CardView
android:layout_width="200dp"
android:layout_height="200dp"
app:cardCornerRadius="3dp"
app:cardUseCompatPadding="true">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/img"/>
</LinearLayout>
</androidx.cardview.widget.CardView>
</RelativeLayout>
在下面的适配器中，我正在获取类别标题和子回收器视图，因为我已成功检索标题但无法解析回收器视图：
CategoryAdapter.kt
class CategoryAdapter(private val context: Context,private val categories:List<Result>): RecyclerView.Adapter<CategoryAdapter.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
return
ViewHolder(ParentRowBinding.inflate(LayoutInflater.from(parent.context),parent,false))
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
val model = categories[position]
holder.binding.catTitle.text = model.category
holder.binding.childRecycler.setHasFixedSize(true)
holder.binding.childRecycler.layoutManager = LinearLayoutManager(context)
val viewModel = ViewModelProvider(context).get(CatImagesViewModel::class.java)
}
override fun getItemCount(): Int {
return categories.size
}
class ViewHolder(val binding:ParentRowBinding): RecyclerView.ViewHolder(binding.root)
}
CatImagesViewModel.kt
class CatImagesViewModel: ViewModel() {
private var catImageList:MutableLiveData<List<List<Sku>>> = MutableLiveData()
fun getCatImg(): LiveData<List<List<Sku>>>{
viewModelScope.launch(Dispatchers.IO) {
val retrofit = RetrofitClient.getRetrofitClient().create(ApiService::class.java)
val response = retrofit.getCatImg()
if(response.isSuccessful){
val skus: MutableList<List<Sku>> = mutableListOf()
val cnt = response.body()!!.result.size
for(i in 0 until cnt){
skus.add(response.body()!!.result[i].sku)
}
catImageList.postValue(skus)
}
}
return catImageList
}
}
下面是在水平视图的子回收器视图中解析图像的适配器：
CatImgAdapter.kt
class CatImgAdapter(private val context: Context,private val imgList:List<Sku>): RecyclerView.Adapter<CatImgAdapter.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
return ViewHolder(ChildRowBinding.inflate(LayoutInflater.from(parent.context),parent,false))
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
val model = imgList[position]
Glide.with(context).load(model.img).into(holder.binding.img)
}
override fun getItemCount(): Int {
return imgList.size
}
data class ViewHolder(val binding:ChildRowBinding): RecyclerView.ViewHolder(binding.root)
}
下面是ViewModel 用于获取类别标题或垂直回收器视图：
CategoriesViewModel.kt
class CategoriesViewModel: ViewModel() {
private var categoryList: MutableLiveData<List<Result>> = MutableLiveData()
fun getAllCategory(): LiveData<List<Result>> {
viewModelScope.launch(Dispatchers.IO) {
val retrofit = RetrofitClient.getRetrofitClient().create(ApiService::class.java)
val response = retrofit.getCategories()
if (response.isSuccessful) {
categoryList.postValue(response.body()!!.result)
}
}
return categoryList
}
}
有人告诉我我做错了什么或实现所需布局的最佳方式。
【问题讨论】：
标签： android kotlin android-recyclerview viewmodel