在 kotlin 中定义了一个类，其中包含成员
@JvmField protected val clickHandler: BaseClickHandler
@JvmField protected var layoutId : Int
但是当在java中试图扩展这个类并访问它的成员时会出错。
interface ViewDelegate {
fun onCreateViewHolder(parent: ViewGroup): RecyclerView.ViewHolder
fun onBindViewHolder(holder: RecyclerView.ViewHolder, item: Data, position: Int)
}
open class ViewDelegateImp(@JvmField protected val clickHandler: BaseClickHandler) : ViewDelegate {
@JvmField protected var layoutId = R.layout.default
override fun onCreateViewHolder(parent: ViewGroup): RecyclerView.ViewHolder {
return ItemViewHolder(parent.inflate(layoutId, false), clickHandler)
}
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, item: Data, position: Int) {
(holder as? ItemViewHolder)?.bindView(item, position)
}
}
//extension:
fun ViewGroup.inflate(layoutId: Int, attachToRoot: Boolean = false): View {
return LayoutInflater.from(context).inflate(layoutId, this, attachToRoot)
}
在 java 中想要从 ViewDelegateImp 派生，并覆盖 var layoutId 并使用受保护的 val clickHandler
class DerivedDelegateImp extends ViewDelegateImp {
public DerivedDelegateImp(BaseClickHandler clickHandler) {
super(clickHandler);
layoutId = R.layout.derived; // want to use different layout, but get error "cannot resolve layoutId"
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, Data item, int position) {
super.onBindViewHolder(holder, item, position);
}
@NotNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent) {
View vw = LayoutInflater.from(parent.getContext()).inflate(layoutId, parent, false);
return new StoryItemViewHolder(vw, clickHandler); // here got error clickHandler has private access in ViewDelegateImp
//return super.onCreateViewHolder(parent); //<== this is fine
}
}