RecyclerView的diffUtil使用代码示范
时间: 2023-04-09 16:01:38 浏览: 62
好的,我可以回答这个问题。以下是RecyclerView的diffUtil使用代码示范:
首先,在你的Adapter类中实现DiffUtil.ItemCallback类,例如:
```
class MyAdapter : RecyclerView.Adapter<MyViewHolder>() {
private val diffCallback = object : DiffUtil.ItemCallback<MyData>() {
override fun areItemsTheSame(oldItem: MyData, newItem: MyData): Boolean {
return oldItem.id == newItem.id
}
override fun areContentsTheSame(oldItem: MyData, newItem: MyData): Boolean {
return oldItem == newItem
}
}
// ...
}
```
然后,在你的Adapter类中使用DiffUtil.calculateDiff()方法来计算差异,例如:
```
class MyAdapter : RecyclerView.Adapter<MyViewHolder>() {
private val diffCallback = object : DiffUtil.ItemCallback<MyData>() {
// ...
}
private var data: List<MyData> = emptyList()
fun setData(newData: List<MyData>) {
val diffResult = DiffUtil.calculateDiff(object : DiffUtil.Callback() {
override fun getOldListSize(): Int = data.size
override fun getNewListSize(): Int = newData.size
override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
return data[oldItemPosition].id == newData[newItemPosition].id
}
override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
return data[oldItemPosition] == newData[newItemPosition]
}
})
data = newData
diffResult.dispatchUpdatesTo(this)
}
// ...
}
```
这样,当你调用setData()方法时,RecyclerView会自动计算出新旧数据之间的差异,并进行相应的更新。