为kotlin中的classrecyclerView项折叠设置onclick-in视图持有者
我正在尝试在我的recyclerView中设置一个简单的折叠项。 我在Java中看到了许多应用程序,但在Kotlin中只有少数。 onBindViewHolder中几乎设置了onClick方法,如下所示:为kotlin中的classrecyclerView项折叠设置onclick-in视图持有者,kotlin,android-recyclerview,adapter,onclicklistener,android-viewholder,Kotlin,Android Recyclerview,Adapter,Onclicklistener,Android Viewholder,我正在尝试在我的recyclerView中设置一个简单的折叠项。 我在Java中看到了许多应用程序,但在Kotlin中只有少数。 onBindViewHolder中几乎设置了onClick方法,如下所示: val isExpandable:Boolean = data[position].expandable holder.subItem.visibility = if(isExpandable) View.VISIBLE else View.GONE holder.m
val isExpandable:Boolean = data[position].expandable
holder.subItem.visibility = if(isExpandable) View.VISIBLE else View.GONE
holder.mainItem.setOnClickListener {
data[position].expandable = !data[position].expandable
notifyItemChanged(position)
}
class MyAdapter(val data:List<MyModel>,
val listener:(MyModel)->Unit):RecyclerView.Adapter<MyAdapter.MyViewHolder>() {
class MyViewHolder(itemView:View):RecyclerView.ViewHolder(itemView){
fun bind (data:MyModel,listener: (MyModel) -> Unit) = with(itemView){
...
view.setOnClickListener {listener(data)}
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder = MyViewHolder(
LayoutInflater.from(parent.context).inflate(R.layout.card_item,parent,false)
)
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.bind(data[position], listener)
}
override fun getItemCount(): Int = data.count()
}
with(my_recycler) {
layoutManager = LinearLayoutManager(this@MainActivity, RecyclerView.VERTICAL, false)
adapter = MyAdapter(it) {
//data can be accessed here according item position
}
}
这项工作做得很好。但是,我读到一些开发人员说,在onBindViewHolder中应用onClick方法不是一个好主意,必须在ViewHolder类中进行。
在使用Kotlin时,我以Koltin的方式应用了onClick方法,使用lambda。像这样:
val isExpandable:Boolean = data[position].expandable
holder.subItem.visibility = if(isExpandable) View.VISIBLE else View.GONE
holder.mainItem.setOnClickListener {
data[position].expandable = !data[position].expandable
notifyItemChanged(position)
}
class MyAdapter(val data:List<MyModel>,
val listener:(MyModel)->Unit):RecyclerView.Adapter<MyAdapter.MyViewHolder>() {
class MyViewHolder(itemView:View):RecyclerView.ViewHolder(itemView){
fun bind (data:MyModel,listener: (MyModel) -> Unit) = with(itemView){
...
view.setOnClickListener {listener(data)}
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder = MyViewHolder(
LayoutInflater.from(parent.context).inflate(R.layout.card_item,parent,false)
)
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.bind(data[position], listener)
}
override fun getItemCount(): Int = data.count()
}
with(my_recycler) {
layoutManager = LinearLayoutManager(this@MainActivity, RecyclerView.VERTICAL, false)
adapter = MyAdapter(it) {
//data can be accessed here according item position
}
}
如果要从适配器访问ViewHolder中的属性,可以将ViewHolder声明为内部类
inner class MyViewHolder(itemView:View):RecyclerView.ViewHolder(itemView){
fun bind (data:MyModel,listener: (MyModel) -> Unit) = with(itemView){
...
view.setOnClickListener {listener(data)}
}
}
我还没有尝试调用notifyItemChanged(position),但是我想说的是,如果它将位于单击侦听器中,它应该不会崩溃。如果您从侦听器外部和调用notifyItemChanged的函数内部调用它,则可能会发生崩溃
让我知道它是否有效