有人使用RecyclerView找到了一种方法来设置一个onClickListener的项目在RecyclerView? 我想设置一个监听器为每个项目的布局,但这似乎有点太麻烦了 我确信有一种方法让RecyclerView监听onClick事件,但我不能完全弄清楚。
当前回答
这是我的自定义适配器的完整代码,这段代码将用XML文件“list_item”中定义的列表项膨胀行,它还将在具有各自位置的所有列表项行上执行单击事件。
public class MyCustomAdapter extends RecyclerView.Adapter`<`AdapterMyCustomAdapter.ViewHolder> {
public static class ViewHolder extends RecyclerView.ViewHolder implements OnClickListener {
public onItemClickListener mListener;
public ViewHolder(View v, onItemClickListener listener) {
super(v);
mListener =listener;
v.setOnClickListener(this);
}
@Override
public void onClick(View v) {
mListener.onRecyclerItemClick(v, getPosition());
}
public static interface onItemClickListener {
public void onRecyclerItemClick(View view , int position);
}
}
@Override
public int getItemCount() {
return 5;
}
@Override
public void onBindViewHolder(ViewHolder holder, int pos) {
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int position) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.list_item, parent, false);
/* here list_item is an xml file we want to inflate ...it is same as we do in case of listview for customization.*/
MyCustomAdapter.ViewHolder vh = new ViewHolder(v, new MyCustomAdapter.ViewHolder.onItemClickListener() {
@Override
public void onRecyclerItemClick(View view, int position) {
System.out.println("clicked on list item at position " +position);
}
});
return vh;
}
}
其他回答
到目前为止,所有的答案都是很好的解决方案,但是如果你不想处理太多的实现细节,只是想让它类似于ListView的工作方式,我建议使用twway - view,如下所示:
https://github.com/lucasr/twoway-view
请注意,这个实现还支持长按项目,以及支持按下状态(这是这个问题的其他解决方案所缺乏的重要内容)。
如果您不想使用整个库,请查看ClickItemTouchListener类,如果需要,可以将其作为独立的类使用。我发现它目前唯一的问题是长按+滚动,它似乎有不正确的行为。
让我们看看如何在Jetpack / AndroidX中实现这一点
你需要像这样在viewmodel类中创建一个观察对象
private MutableLiveData<Integer> adapterItem = new MutableLiveData<>();
public MutableLiveData<Integer> getAdapterItem() {
return adapterItem;
}
public void setAdapterItem(int adapterItem) {
this.getAdapterItem().setValue(adapterItem);
}
然后在适配器类中,确保将viewmodel引用作为构造函数的参数传递,然后在vieholder上实现clicklistener
public MyViewHolder(@NonNull View itemView) {
super(itemView);
if(itemView != null){
itemView.setOnClickListener(v -> {
int adapterPosition = getAdapterPosition();
viewModel.setAdapterItem(adapterPosition);
});
};
}
然后从活动课上观察变化
viewModel.getAdapterItem().observe(this, position -> {
Log.w(TAG, "clicked: " + ridesArray.get(position));
});
这对我来说很难在活动中有一个项目点击监听器,也有一个项目的单一视图的点击监听器,不会触发项目点击监听器。在玩了Jacob Tabak的回答后,我尊重他的回答,如果项目内没有其他触摸操作,就点击项目。
我有一个自定义OnClickListener接口,有一个项目点击事件,它持有从适配器点击的项目的视图和项目的位置。我在构造函数(或者它可以是setter)中呈现它的一个实例,并将它附加到视图持有者容器click listener。
我也有其他的点击监听器在适配器(可以在视图持有人),这将处理当前的视图点击从容器。
public class MyRecyclerAdapter extends RecyclerView.Adapter<MyViewHolder> {
private ArrayList<String> mData;
private OnItemClickListener mOnItemClickListener;
public interface OnItemClickListener {
public void onItemClick(View view, int position);
}
public MyRecyclerAdapter(ArrayList<String> itemsData,
OnItemClickListener onItemClickListener) {
mOnItemClickListener = onItemClickListener;
this.mData = itemsData;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View layoutView = LayoutInflater.from(mContext).inflate(
R.layout.list_item, parent, false);
final MyViewHolder viewHolder = new MyViewHolder(layoutView);
viewHolder.container.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mOnItemClickListener.onItemClick(v, viewHolder.getAdapterPosition());
}
});
viewHоlder.button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
//do button click work here with
// mData.get( viewHolder.getAdapterPosition() );
}
});
return viewHolder;
}
@Override
public int getItemCount() {
return mData.size();
}}
在活动中,您需要通过传递OnItemClickListener实例来初始化适配器
public class FeedActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
...
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
.....
MyRecyclerAdapter adapter = new MyRecyclerAdapter(new ArrayList<String>(), new OnItemClickListener() {
@Override
public void onItemClick(View view, int position) {
///list item was clicked
}
});
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(mFeedsAdapter);
}
还有我的ViewHolder
public class MyViewHolder extends RecyclerView.ViewHolder {
public Button button;
public View container;
public MyViewHolder(View itemLayoutView) {
super(itemLayoutView);
container = itemLayoutView;
button = (Button) itemLayoutView.findViewById(R.id.button);
}}
在ViewHolder中设置点击监听器,如下所示:
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView title, year, genre;
public MyViewHolder(View view) {
super(view);
title = (TextView) view.findViewById(R.id.title);
genre = (TextView) view.findViewById(R.id.genre);
year = (TextView) view.findViewById(R.id.year);
view.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(context, ""+getAdapterPosition(), Toast.LENGTH_SHORT).show();
}
});
}
}
将类标记为抽象并实现OnClick方法
public abstract class MainGridAdapter extends
RecyclerView.Adapter<MainGridAdapter.ViewHolder> {
private List<MainListItem> mDataset;
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView txtHeader;
public TextView txtFooter;
public ViewHolder(View v) {
super(v);
txtHeader = (TextView) v.findViewById(R.id.firstLine);
txtFooter = (TextView) v.findViewById(R.id.secondLine);
}
}
public void add(int position, MainListItem item) {
mDataset.add(position, item);
notifyItemInserted(position);
}
public void remove(MainListItem item) {
int position = mDataset.indexOf(item);
mDataset.remove(position);
notifyItemRemoved(position);
}
// Provide a suitable constructor (depends on the kind of dataset)
public MainGridAdapter(List<MainListItem> myDataset) {
mDataset = myDataset;
}
// Create new views (invoked by the layout manager)
@Override
public MainGridAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext()).inflate(
R.layout.list_item_grid_line, parent, false);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(v);
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
OnClickListener clickListener = new OnClickListener() {
@Override
public void onClick(View v) {
onItemClicked(position);
}
};
holder.itemView.setOnClickListener(clickListener);
holder.txtHeader.setOnClickListener(clickListener);
holder.txtFooter.setOnClickListener(clickListener);
final MainListItem item = mDataset.get(position);
holder.txtHeader.setText(item.getTitle());
if (TextUtils.isEmpty(item.getDescription())) {
holder.txtFooter.setVisibility(View.GONE);
} else {
holder.txtFooter.setVisibility(View.VISIBLE);
holder.txtFooter.setText(item.getDescription());
}
}
// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
return mDataset.size();
}
public abstract void onItemClicked(int position);
}
在绑定事件中实现单击处理程序,使其只有一个事件实现
执行此:
mAdapter = new MainGridAdapter(listItems) {
@Override
public void onItemClicked(int position) {
showToast("Item Clicked: " + position, ToastPlus.STYLE_INFO);
}
};
同样可以做长时间点击
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