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
From most of the answers above, they seem to be setting their onclicklisteners to individual items. However, the solution am about to offer is very simple but yet not intuitive to many. Many are forgetting that the other components are always in a parent component which is used to display items in the List or Recycler views. This solution is just about setting a single onclick listener to this parent view and the turn is played. The solution also includes a way to pass the position of the item being clicked on from the list or recycler view. Here, our main rootview is a CardView from the android support library. Here is sample code
public class ListAdapter extends RecyclerView.Adapter<ListAdapter.ViewHolder> {
public static final String LOG_TAG = ListAdapter.class.getSimpleName();
private Cursor mDataset;
private Context mContext;
private ViewHolder mViewHolder;
// Provide a suitable constructor (depends on the kind of dataset)
public ListAdapter(Context context, Cursor Dataset) {
mDataset = Dataset;
mContext = context;
}
// Create new views (invoked by the layout manager)
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.list_business_view, parent, false);
mViewHolder = new ViewHolder(v);
return mViewHolder;
}
public void setData(Cursor newdata) {
this.mDataset = newdata;
}
// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
//Bind data to other items here. To save time, i have ommited that.
//here is where we attach a click listerner for an item in the recycler list rather than for each element of a given item.
holder.card.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mContext, " Just cliked item at position " + itemPosition, Toast.LENGTH_LONG).show();
}
});
}
}
// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
if (null != mDataset) {
return mDataset.getCount();
}
return 0;
}
// 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 static class ViewHolder extends RecyclerView.ViewHolder{
// each data item is just a string in this case
public final TextView mBusinesssName; // View for the business name
public final TextView mBusinessCategory; //View for the category name
public final ImageView businessImage; // View for the business category image Image
public final TextView mBusinessDistance; // View for the distance
public final CardView card;
public ViewHolder(View view) {
super(view);
mBusinesssName = (TextView) view.findViewById(R.id.list_item_name_textview);
mBusinessCategory = (TextView) view.findViewById(R.id.list_item_category_textview);
mBusinessDistance = (TextView) view.findViewById(R.id.list_item_dist_textview);
businessImage = (ImageView) view.findViewById(R.id.list_item_icon);
card = (CardView) view.findViewById(R.id.card_view);
}
}
}
其他回答
根据Yigit Boyar的说法,在RecyclerView上注册点击的最好方法是在ViewHolder的创建中定义点击,而不是仅仅为onBindViewHolder绑定的每个项目创建一个新的onClickListener
例子:
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseViewHolder<*> {
val itemBinding = LayoutInflater.from(context).inflate(R.layout.my_layout, parent, false)
val vh = MainViewHolder (itemBinding)
vh.itemView.setOnClickListener {
val pos = vh.adapterPosition
if(pos != NO_POSITION){
itemClickLister.onCocktailClick(myList[pos],pos)
}
}
return vh
}
由于API已经发生了根本性的变化,如果你要为每个项目创建一个OnClickListener,这不会让我感到惊讶。不过也没那么麻烦。在你的RecyclerView的实现中。适配器<MyViewHolder>,你应该有:
private final OnClickListener mOnClickListener = new MyOnClickListener();
@Override
public MyViewHolder onCreateViewHolder(final ViewGroup parent, final int viewType) {
View view = LayoutInflater.from(mContext).inflate(R.layout.myview, parent, false);
view.setOnClickListener(mOnClickListener);
return new MyViewHolder(view);
}
onClick方法:
@Override
public void onClick(final View view) {
int itemPosition = mRecyclerView.getChildLayoutPosition(view);
String item = mList.get(itemPosition);
Toast.makeText(mContext, item, Toast.LENGTH_LONG).show();
}
这里有一个策略,它给出了一个类似于ListView实现的结果,因为你可以在活动或片段级别而不是适配器或ViewHolder级别定义侦听器。它还定义了一些抽象类,这些抽象类负责适配器和持有者的大量样板工作。
抽象类
首先,定义一个抽象Holder,它扩展了RecyclerView。并定义了一个泛型数据类型T,用于将数据绑定到视图。bindViews方法将由一个子类实现,用于将数据映射到视图。
public abstract class Holder<T> extends RecyclerView.ViewHolder {
T data;
public Holder(View itemView) {
super(itemView);
}
public void bindData(T data){
this.data = data;
bindViews(data);
}
abstract protected void bindViews(T data);
}
同样,创建一个抽象适配器,扩展RecyclerView.Adapter<Holder<T>>。这定义了3个接口方法中的2个,子类将需要实现最后一个onViewHolderCreated方法。
public abstract class Adapter<T> extends RecyclerView.Adapter<Holder<T>> {
List<T> list = new ArrayList<>();
@Override
public void onBindViewHolder(Holder<T> holder, int position) {
holder.bindData(list.get(position));
}
@Override
public int getItemCount() {
return list.size();
}
public T getItem(int adapterPosition){
return list.get(adapterPosition);
}
}
具体类
现在创建一个扩展Holder的新具体类。该方法只需定义视图并处理绑定。这里我使用ButterKnife库,但请随意使用itemView.findViewById(…)方法代替。
public class PersonHolder extends Holder<Person>{
@Bind(R.id.firstname) TextView firstname;
@Bind(R.id.lastname) TextView lastname;
public PersonHolder(View view){
super(view);
ButterKnife.bind(this, view);
}
@Override
protected void bindViews(Person person) {
firstname.setText(person.firstname);
lastname.setText(person.lastname);
}
}
最后,在持有RecyclerView的Activity或Fragment类中,你会有这样的代码:
// Create adapter, this happens in parent Activity or Fragment of RecyclerView
adapter = new Adapter<Person>(){
@Override
public PersonHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.layout_person_view, parent, false);
PersonHolder holder = new PersonHolder(v);
v.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
int itemPos = holder.getAdapterPosition();
Person person = getItem(itemPos);
// do something with person
EventBus.getDefault().postSticky(new PersonClickedEvent(itemPos, person));
}
});
return holder;
}
};
对于kotlin句柄,根据Jacobs的回答单击RecyclerView答案
创建类RecyclerItemClickListener:
class RecyclerItemClickListener(context: Context, recyclerView: RecyclerView, listner: OnItemClickListener) : RecyclerView.OnItemTouchListener {
var mGestureDetector: GestureDetector
var mListner: OnItemClickListener
interface OnItemClickListener {
fun onItemClick(view: View, position: Int)
fun onLongItemClick(view: View, position: Int)
}
init {
this.mListner = listner
mGestureDetector = GestureDetector(context, object : GestureDetector.SimpleOnGestureListener() {
override fun onSingleTapUp(e: MotionEvent?): Boolean = true
override fun onLongPress(e: MotionEvent?) {
val child: View? = recyclerView.findChildViewUnder(e!!.getX(), e.getY())
if (child != null && mListner != null) {
mListner.onLongItemClick(child, recyclerView.getChildAdapterPosition(child))
}
}
})
}
override fun onTouchEvent(rv: RecyclerView, e: MotionEvent) = Unit
override fun onInterceptTouchEvent(view: RecyclerView, e: MotionEvent): Boolean {
val childView: View? = view.findChildViewUnder(e!!.getX(), e.getY())
if (childView != null && mListner != null && mGestureDetector.onTouchEvent(e)) {
mListner.onItemClick(childView, view.getChildAdapterPosition(childView))
return true
}
return false
}
override fun onRequestDisallowInterceptTouchEvent(disallowIntercept: Boolean) = Unit
}
点击Any RecyclerView(在活动/片段内):
recyclerView.addOnItemTouchListener(
RecyclerItemClickListener(this, recyclerView, object : RecyclerItemClickListener.OnItemClickListener {
override fun onItemClick(view: View, position: Int) {
// TODO catch click
}
override fun onLongItemClick(view: View, position: Int) {
// TODO catch click
}
})
)
以下是我所做的。这个解决方案同时支持onClick和onLongClick在两个RecyclerView项目和视图内的RecyclerView项目(内部视图)。
我在我选择的视图上标记viewHolder:
public RecyclerViewAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_item, null);
ViewHolder viewHolder = new ViewHolder(itemView);
itemView.setOnClickListener( this);
itemView.setOnLongClickListener(this);
viewHolder.imageIV.setOnClickListener(this);
viewHolder.imageIV.setOnLongClickListener(this);
viewHolder.imageIV.setTag(viewHolder);
itemView.setTag(viewHolder);
return viewHolder;
}
我使用holder.getPosition()在onClick()方法中检索位置(onLongClick类似):
public void onClick(View view) {
ViewHolder holder = (ViewHolder) view.getTag();
int position = holder.getPosition();
if (view.getId() == holder.imageIV.getId()){
Toast.makeText(context, "imageIV onClick at" + position, Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(context, "RecyclerView Item onClick at " + position, Toast.LENGTH_SHORT).show();
}
}
带有getChildPosition的变体也可以工作。请注意,对于内部视图,在onClick()中使用:
int position = recyclerView.getChildPosition((View)view.getParent());
在我看来,这个解决方案的优点是,当一个人点击图像,只有onclick()图像侦听器被调用,而当我结合Jacob的解决方案为一个RecyclerView项目视图和我的解决方案为内部视图的RecyclerView项目视图onclick()也被调用(当点击图像)。
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