英文:
Android Kotlin - How do I assign a name function in main activity class to setOnClickListener in another class?
问题
请检查下面的示例代码和注释，
class MainActivity : AppCompatActivity(), MyListener {
fun OnViewItemClicked(){
// 做一些事情
}
}
class AnotherClass() : RecyclerView.Adapter<MyAdapter.ViewHolder>() {
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
// 如何将此设置为在MainActivity类中声明的OnViewItemClicked？
holder.itemView.setOnClickListener(OnViewItemClicked);
}
}
希望这对你有帮助。
英文:
Please check the sample code and comments below,
class MainActivity : AppCompatActivity(), MyListener {
fun OnViewItemClicked(){
// do something
}
}
class AnotherClass() : RecyclerView.Adapter<MyAdapter.ViewHolder>() {
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
// how do i set this to OnViewItemClicked declared in class MainActivity?
holder.itemView.setOnClickListener(OnViewItemClicked);
}
}
答案1
得分: 3
只需将Listener实例传递给适配器，如下所示：
val adapter = AnotherClass(this@MainActivity)
然后在适配器中：
class AnotherClass(private val listener: MainActivity): RecyclerView.Adapter<MyAdapter.ViewHolder>() {
// ...
// ...
holder.itemView.setOnClickListener {
listener.OnViewItemClicked()
}
// ...
}
Explanation -
这是通过kotlin lambda完成的，等同于：
val clickLambda: (View) -> Unit = {
listener.OnViewItemClicked()
}
Edit :- 而不是这样做，您可以直接从活动中传递一个类型为(View) -> Unit的lambda表达式！
英文:
Just pass the Listener instance to the adapter:- like :-
val adapter = AnotherClass(this@MainActivity)
Then in adapter
class AnotherClass(private val listener: MainActivity): RecyclerView.Adapter<MyAdapter.ViewHolder>() {
....
....
holder.itemView.setOnClickListener {
listener.OnViewItemClicked()
}
....
}
Explanation -
This is done with the help of kotlin lambda , i.e, equivalent to :-
val clickLambda: (View) -> Unit = {
listener.OnViewItemClicked()
}
Edit :- Instead of doing this you can directly pass in a lambda of type (View) -> Unit from the activity !
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