问题
I have two tabs in which I add two different lists of data, both tabs share a single recyclerview, so at my viewpager adapter, I just create a new instance to populate the data
From the View
val allProducts = completeProductList
val productsList = mutableListOf<Products>()
val drinksList = mutableListOf<Products>()
for (product in allProducts) {
if (product.isDrink) {
drinksList.add(product)
} else {
productsList.add(product)
}
}
viewPagerAdapter.productsList = productsList
viewPagerAdapter.drinksList = drinksList
viewPagerAdapter.notifyDataSetChanged()
Adapter
class PagerAdapter(fragmentActivity: FragmentActivity) :
FragmentStateAdapter(fragmentActivity) {
var productsList: MutableList<Product> = arrayListOf()
var drinksList: MutableList<Product> = arrayListOf()
override fun getItemCount(): Int {
return 2
}
override fun createFragment(position: Int): Fragment {
return when(position){
0 -> {
FragmentProducts.newInstance(productsList)
}
else -> {
FragmentProducts.newInstance(drinksList)
}
}
}
}
Then in my FragmentProducts
companion object {
fun newInstance(product: MutableList<Product>) = FragmentProducts().apply {
arguments = Bundle().apply {
putParcelableArrayList(ARG_PROD,ArrayList<Parcelable>(product))
}
}
}
// I get the product list from the adapter, either drinks or normal products
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
arguments?.let {
productsList = it.getParcelableArrayList<Product>(ARG_PROD)
}
}
// Then I just set it up to the shared recyclerview
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
adapter.productsList = productsList!!
adapter.notifyDataSetChanged()
}
So, the list is displayed correctly, lets say I have two tabs, first tab has 2 items and second tab has 1 item, so, If I click on item 1 at tab 1 I get its id and get the right product, then if I click item 2 on tab 1 it also works, when I swipe to tab 2 and click item 1 it will display correctly again the item, but, if I go back to tab 1 and click item 2 it will throw a IndexOutOfBoundsException
, it seems like when swiping back it takes the latest recyclerview data set
I dont know how to fix this to prevent creating a different fragment for tab 2 since they show the same data
I need to know what is happening, it seems that the last FragmentProducts.newInstance(drinksList) is replacing the whole recyclerview at tab 1
StackTrace
java.lang.IndexOutOfBoundsException: Index: 1, Size: 1 at java.util.ArrayList.get(ArrayList.java:411) at com.StoreAdapter.getItem(StoreAdapter.kt:45) at com.FragmentProducts.onCartClick(FragmentProducts.kt:65) at com.StoreAdapter$StoreViewHolder$bind$1.onClick(StoreAdapter.kt:59)
StoreAdapter error at this line
fun getItem(position: Int):Product{
return productList[position]
}
来源:https://stackoverflow.com/questions/60663662/viewpager-with-two-tabs-causes-indexoutofboundsexception-when-sliding-and-clicki