1. Function
1. Renderings
The top, bottom, right and left of item are all 0
2. Code
1. Key code
//Set the spacing between RecycleView items. The upper and lower spacing is 20 for sorting, and the left and right spacing is 20 for sorting.
binding.rv.addItemDecoration(object : RecyclerView.ItemDecoration() {<!-- -->
override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {<!-- -->
val position = parent.getChildAdapterPosition(view) // Get the position of the item
val spanCount = 2 // number of columns
val itemCount = parent.adapter?.itemCount ?: 0 //Total number of items
val spacing = 20 // spacing
val row = position / spanCount // row number
val lastRow = (itemCount - 1) / spanCount //The line number of the last row
//If it is the first column, set right, if it is the second column, just set left
if (position%spanCount==0){<!-- -->
outRect.right=20
}else{<!-- -->
outRect.left=20
}
if (row == 0) {<!-- --> // If it is the first row, no upper spacing is set
outRect.top = 0
} else {<!-- --> // Otherwise, set the upper spacing to 20
outRect.top = spacing
}
if (row == lastRow) {<!-- --> // If it is the last row, no lower spacing is set
outRect.bottom = 0
} else {<!-- --> // Otherwise, set the lower spacing to 20
outRect.bottom = spacing
}
}
})
2. Approximate code
//Create a list to store data
val itemList = listOf(
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp),
Item("Apple", R.drawable.ic_home_black_24dp)
)
//Set the layout manager of RecycleView to GridLayoutManager and specify the number of columns to 2
binding.rv.layoutManager = GridLayoutManager(activity, 2)
//Set the adapter of RecycleView to ItemAdapter and pass in the list data
binding.rv.adapter = ItemAdapter(itemList)
//Set the spacing between RecycleView items, the top and bottom spacing is 20 for sorting, and the left and right spacing is 20 for sorting
binding.rv.addItemDecoration(object : RecyclerView.ItemDecoration() {<!-- -->
override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {<!-- -->
val position = parent.getChildAdapterPosition(view) // Get the position of the item
val spanCount = 2 // number of columns
val itemCount = parent.adapter?.itemCount ?: 0 //Total number of items
val spacing = 20 // spacing
val row = position / spanCount // row number
val lastRow = (itemCount - 1) / spanCount //The line number of the last row
//If it is the first column, set right, if it is the second column, just set left
if (position%spanCount==0){<!-- -->
outRect.right=20
}else{<!-- -->
outRect.left=20
}
if (row == 0) {<!-- --> // If it is the first row, no upper spacing is set
outRect.top = 0
} else {<!-- --> // Otherwise, set the upper spacing to 20
outRect.top = spacing
}
if (row == lastRow) {<!-- --> // If it is the last row, no lower spacing is set
outRect.bottom = 0
} else {<!-- --> // Otherwise, set the lower spacing to 20
outRect.bottom = spacing
}
}
})
adapter and item
//Create a data class to store the data of the list
data class Item(val name: String, val image: Int)
//Create an adapter class, inherited from RecyclerView.Adapter
class ItemAdapter(private val itemList: List<Item>) : RecyclerView.Adapter<ItemAdapter.ItemViewHolder>() {<!-- -->
//Create an inner class for binding views and data
class ItemViewHolder(val binding: ItemLayoutBinding) : RecyclerView.ViewHolder(binding.root)
// Override the onCreateViewHolder method to create views
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ItemViewHolder {<!-- -->
val binding = ItemLayoutBinding.inflate(LayoutInflater.from(parent.context), parent, false)
return ItemViewHolder(binding)
}
// Override the onBindViewHolder method for binding data
override fun onBindViewHolder(holder: ItemViewHolder, position: Int) {<!-- -->
val item = itemList[position]
holder.binding.itemName.text = item.name
holder.binding.itemImage.setImageResource(item.image)
}
// Override the getItemCount method to return the size of the list
override fun getItemCount(): Int {<!-- -->
return itemList.size
}
}