我有三个班级。片段,RecyclerViewAdapter和RecyclerViewHolder。他们以通常的方式工作。但是现在我遇到了一个问题,我需要在ViewHolder中调用一个方法。
我正在考虑使用回调,但我尝试了它并没有工作。这是我到目前为止所做的:
界面
public interface TreeBottomListener {
enum Status {FAILED, SUCCESS, PRE_REQUEST}
void onResponse(Status status);
}
ViewHolder
public class TreeBottomViewHolder extends RecyclerView.ViewHolder implements TreeBottomListener{
@BindView(R.id.tree_bottom_progress) ProgressBar bottomProgress;
@BindView(R.id.tree_error_button) Button moreRetryButton;
private TreeAdapterListener listener;
private final String TAG = "TreeBottomViewHolder";
public TreeBottomViewHolder(View itemView, final TreeAdapterListener listener) {
super(itemView);
ButterKnife.bind(this, itemView);
this.listener = listener;
setUpViews();
}
private void setUpViews() {
bottomProgress.getIndeterminateDrawable().setColorFilter(ContextCompat.getColor
(itemView.getContext(), R.color.colorAccent), PorterDuff.Mode.SRC_IN);
moreRetryButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
v.setVisibility(View.GONE);
listener.onLoadMoreClicked();
}
});
}
@Override
public void onResponse(Status status) {
processViews(status);
}
private void processViews(Status status) {
// This method is never called
Log.i(TAG, "onResponse: with status " + status);
if (status == Status.FAILED) {
bottomProgress.setVisibility(View.GONE);
moreRetryButton.setVisibility(View.VISIBLE);
} else if (status == Status.SUCCESS) {
bottomProgress.setVisibility(View.GONE);
} else if (status == Status.PRE_REQUEST) {
bottomProgress.setVisibility(View.VISIBLE);
}
}
}
片段
private TreeBottomListener bottomListener = bottomCallbacks;
private static TreeBottomListener bottomCallbacks = new TreeBottomListener() {
@Override
public void onResponse(Status status) {
}
};
// I do this say when a network request is about to be sent
bottomListener.onResponse(TreeBottomListener.Status.PRE_REQUEST);
答案 0 :(得分:2)
您可以调用此方法(YourAdapter.TreeBottomViewHolder)recyclerView.findViewHolderForLayoutPosition(position);
它返回ViewHolder,您可以使用以下代码检查项目位置:
private boolean isCurrentListViewItemVisible(int position) {
LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
int first = layoutManager.findFirstVisibleItemPosition();
int last = layoutManager.findLastVisibleItemPosition();
return first <= position && position <= last;
}
然后您可以执行以下操作:
TreeBottomViewHolder holder = (YourAdapter.TreeBottomViewHolder)recyclerView.findViewHolderForLayoutPosition(position);
if(isCurrentListViewItemVisible(position)){
// you can access your views here
}
我希望它对你有所帮助。