我正在探索RecyclerView,我很惊讶地看到,RecyclerView没有onItemClickListener()。
我有两个问题。
主要问题
我想知道为什么谷歌删除onItemClickListener()?
是否存在性能问题或其他问题?
次要的问题
我解决了我的问题写onClick在我的RecyclerView。适配器:
public static class ViewHolder extends RecyclerView.ViewHolder implements OnClickListener {
public TextView txtViewTitle;
public ImageView imgViewIcon;
public ViewHolder(View itemLayoutView) {
super(itemLayoutView);
txtViewTitle = (TextView) itemLayoutView.findViewById(R.id.item_title);
imgViewIcon = (ImageView) itemLayoutView.findViewById(R.id.item_icon);
}
@Override
public void onClick(View v) {
}
}
这样可以吗/有更好的办法吗?
看看我的方法:
首先像这样声明一个接口:
/**
* Interface used for delegating item click events in a {@link android.support.v7.widget.RecyclerView}
* Created by Alex on 11/28/2015.
*/
public interface OnRecyclerItemClickListener<T> {
/**
* Called when a click occurred inside a recyclerView item view
* @param view that was clicked
* @param position of the clicked view
* @param item the concrete data that is displayed through the clicked view
*/
void onItemClick(View view, int position, T item);
}
然后创建适配器:
public class CustomRecyclerAdapter extends RecyclerView.Adapter {
private class InternalClickListener implements View.OnClickListener{
@Override
public void onClick(View v) {
if(mRecyclerView != null && mItemClickListener != null){
// find the position of the item that was clicked
int position = mRecyclerView.getChildAdapterPosition(v);
Data data = getItem(position);
// notify the main listener
mItemClickListener.onItemClick(v, position, data);
}
}
}
private final OnRecyclerItemClickListener mItemClickListener;
private RecyclerView mRecyclerView;
private InternalClickListener mInternalClickListener;
/**
*
* @param itemClickListener used to trigger an item click event
*/
public PlayerListRecyclerAdapter(OnRecyclerItemClickListener itemClickListener){
mItemClickListener = itemClickListener;
mInternalClickListener = new InternalClickListener();
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_item, parent, false);
v.setOnClickListener(mInternalClickListener);
ViewHolder viewHolder = new ViewHolder(v);
return viewHolder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
// do your binding here
}
@Override
public int getItemCount() {
return mDataSet.size();
}
@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
mRecyclerView = recyclerView;
}
@Override
public void onDetachedFromRecyclerView(RecyclerView recyclerView) {
super.onDetachedFromRecyclerView(recyclerView);
mRecyclerView = null;
}
public Data getItem(int position){
return mDataset.get(position);
}
}
现在让我们看看如何从一个片段中整合这个:
public class TestFragment extends Fragment implements OnRecyclerItemClickListener<Data>{
private RecyclerView mRecyclerView;
@Override
public void onItemClick(View view, int position, Data item) {
// do something
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.test_fragment, container, false);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
mRecyclerView = view.findViewById(idOfTheRecycler);
mRecyclerView .setAdapter(new CustomRecyclerAdapter(this));
}
检查这一个,我已经实现了所有的事情与适当的方式
RecyclerViewHolder类
public class RecyclerViewHolder extends RecyclerView.ViewHolder {
//view holder is for girdview as we used in the listView
public ImageView imageView,imageView2;
public RecyclerViewHolder(View itemView) {
super(itemView);
this.imageView=(ImageView)itemView.findViewById(R.id.image);
}
}
适配器
public class RecyclerView_Adapter extends RecyclerView.Adapter<RecyclerViewHolder> {
//RecyclerView will extend to recayclerview Adapter
private ArrayList<ModelClass> arrayList;
private Context context;
private static RecyclerViewClickListener itemListener;
//constructor of the RecyclerView Adapter
RecyclerView_Adapter(Context context,ArrayList<ModelClass> arrayList,RecyclerViewClickListener itemListener){
this.context=context;
this.arrayList=arrayList;
this.itemListener=itemListener;
}
@Override
public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//this method will inflate the custom layout and return as viewHolder
LayoutInflater layoutInflater=LayoutInflater.from(parent.getContext());
ViewGroup mainGroup=(ViewGroup) layoutInflater.inflate(R.layout.single_item,parent,false);
RecyclerViewHolder listHolder=new RecyclerViewHolder(mainGroup);
return listHolder;
}
@Override
public void onBindViewHolder(RecyclerViewHolder holder, final int position) {
final ModelClass modelClass=arrayList.get(position);
//holder
RecyclerViewHolder mainHolder=(RecyclerViewHolder)holder;
//convert the drawable image into bitmap
Bitmap image= BitmapFactory.decodeResource(context.getResources(),modelClass.getImage());
//set the image into imageView
mainHolder.imageView.setImageBitmap(image);
//to handle on click event when clicked on the recyclerview item and
// get it through the RecyclerViewHolder class we have defined the views there
mainHolder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//get the position of the image which is clicked
itemListener.recyclerViewListClicked(v,position);
}
});
}
@Override
public int getItemCount() {
return (null!=arrayList?arrayList.size():0);
}
}
的接口
public interface RecyclerViewClickListener {
//this is method to handle the event when clicked on the image in Recyclerview
public void recyclerViewListClicked(View v,int position);
}
//and to call this method in activity
RecyclerView_Adapter adapter=new RecyclerView_Adapter(Wallpaper.this,arrayList,this);
recyclerView.setAdapter(adapter);
adapter.notifyDataSetChanged();
@Override
public void recyclerViewListClicked(View v,int position){
imageView.setImageResource(wallpaperImages[position]);
}
如果您有一个pojo列表,并且希望从适配器外部单击检索一个pojo,那么这里有一种非常容易实现它的方法。
在你的适配器中,为点击事件创建一个监听器和一个方法来设置它:
public class MyAdapter extends RecyclerView.Adapter<SitesListAdapter.ViewHolder> {
...
private List<MyPojo> mMyPojos;
private static OnItemClickListener mOnItemClickListener;
...
public interface OnItemClickListener {
public void onItemClick(MyPojo pojo);
}
...
public void setOnItemClickListener(OnItemClickListener onItemClickListener){
mOnItemClickListener = onItemClickListener;
}
...
}
在你的ViewHolder中,实现onClickListener并创建一个类成员来临时存储视图所呈现的POJO(这是一个例子,创建一个setter会更好):
public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public MyPojo mCurrentPojo;
...
public ViewHolder(View view) {
super(v);
...
view.setOnClickListener(this); //You could set this on part of the layout too
}
...
@Override
public void onClick(View view) {
if(mOnItemClickListener != null && mCurrentPojo != null){
mOnItemClickListener.onItemClick(mCurrentPojo);
}
}
回到你的适配器,当ViewHolder被绑定时设置当前POJO(如果当前视图没有,则设置为null):
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
final MyPojo currentPojo = mMyPojos.get(position);
holder.mCurrentPojo = currentPojo;
...
就是这样,现在你可以在你的fragment/activity中这样使用它:
mMyAdapter.setOnItemClickListener(new mMyAdapter.OnItemClickListener() {
@Override
public void onItemClick(MyPojo pojo) {
//Do whatever you want with your pojo here
}
});
我喜欢这样,我正在用它
内部
public Adapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
Put
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.view_image_and_text, parent, false);
v.setOnClickListener(new MyOnClickListener());
在任何你想要的地方创建这个类
class MyOnClickListener implements View.OnClickListener {
@Override
public void onClick(View v) {
int itemPosition = recyclerView.indexOfChild(v);
Log.e("Clicked and Position is ",String.valueOf(itemPosition));
}
}
我以前读过有一个更好的方法,但我喜欢这个方法,简单,不复杂。
我发现了使用androidx生命周期可变实时数据的最短方法之一
适配器:
private val onItemClickListener = MutableLiveData<YourAdapterItem>()
override fun onBindViewHolder(holder: GifsViewHolder, position: Int) {
holder.itemView.setOnClickListener { onItemClickListener.value = gifs[position] }
}
fun getOnItemClickListener(): MutableLiveData<Gif> {
return onItemClickListener
}
MainActivity的任何地方
yourFancyAdapter.getOnItemClickListener().observe(this, Observer {
println(it)
})
最简单的方法如下:
在Adapter类开始时声明全局变量:
// Store out here so we can resuse
private View yourItemView;
然后在onBindViewHolder方法中设置OnClickListener:
@Override
public void onBindViewHolder(BusinessAdapter.ViewHolder holder, int position) {
// Set up the on click listener
yourItemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mContext,Integer.toString(position),Toast.LENGTH_SHORT).show();
}
});
}
其他答案都不正确。