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
RecyclerView没有OnClickListener,必须自己实现它。
我喜欢在适配器中添加OnItemClickListener接口,当您从ViewHolder中单击项目视图时调用onClick方法。因此,管理项目点击的职责不在ViewHolder和Adapter的范围内。将决定做什么的活动或片段
为监听器和监听器对象添加接口。
public class ItemsAdapter extends RecyclerView.Adapter<ItemsAdapter.ViewHolder> {
...
private static OnItemClickListener onItemClickListener;
...
public static interface OnItemClickListener {
public void onItemClick(View view, int position);
}
...
}
我们捕获项目根视图的单击,以及当回调触发时适配器上的onClick侦听器调用。
public class ItemsAdapter extends RecyclerView.Adapter<ItemsAdapter.ViewHolder> {
...
private static OnItemClickListener onItemClickListener;
...
public static interface OnItemClickListener {
public void onItemClick(View view, int position);
}
...
public static class ViewHolder extends RecyclerView.ViewHolder {
public ImageView imageView;
public ViewHolder(View itemRootView) {
super(itemRootView);
imageView = (ImageView) itemRootView.findViewById(R.id.itemImage);
itemRootView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int position = ViewHolder.super.getAdapterPosition();
onItemClickListener.onItemClick(view,position);
}
});
}
}
}
由于活动或片段,片段在我们的情况下,我们分配一个监听器到适配器和onClick回调,我们将获得选定的项目的位置和打开一个详细的活动项目。
public class ItemsFragment extends Fragment {
...
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
...
((ItemsAdapter) adapter).setOnItemClickListener(new ItemsAdapter.OnItemClickListener() {
@Override
public void onItemClick(View view, int position) {
//Do something when an item has been clicked
}
});
...
}
...
}
其他回答
在kotlin中使用构造函数实现
初始化你的RecyclerView构造函数,如下所示:
class ListAdapter(
c: Context,
private var list: List<Project>,
private val itemClick: (Project) -> Unit
) : RecyclerView.Adapter<ListAdapter.ViewHolder>()
在onCreateViewHolder中使用itemClick返回:
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int):ProjectViewHolder {
val view = inflater.inflate(R.layout.list_item, parent, false)
return ViewHolder(view, itemClick)
}
你的onBindViewHolder:
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.bindProject(list[position])
}
然后用ViewHolder类创建bindProject函数。
class ViewHolder(
view: View,
private val itemClick: (Project) -> Unit
) : RecyclerView.ViewHolder(view) {
private val clientTextCount = 7
val titleTextView: TextView = view.projectTitleTextView
fun bindProject(project: Project) {
with(project) {
titleTextView.text = name
itemView.setOnClickListener { itemClick(this) }
}
}
}
最后在您的活动中用lazy初始化适配器
private val adapter: ListAdapter by lazy {
ListAdapter(this, projectList, {
// Here you can implement your onClick function.
})
}
在适配器中为RecyclerView添加新列表初始化以下方法:
fun setProjects(projects: List<Project>) {
projectList = projects
notifyDataSetChanged()
}
在你的活动中调用setProjects方法:
adapter.setProjects(projects)
就是这样。
RecyclerView没有OnClickListener,必须自己实现它。
我喜欢在适配器中添加OnItemClickListener接口,当您从ViewHolder中单击项目视图时调用onClick方法。因此,管理项目点击的职责不在ViewHolder和Adapter的范围内。将决定做什么的活动或片段
为监听器和监听器对象添加接口。
public class ItemsAdapter extends RecyclerView.Adapter<ItemsAdapter.ViewHolder> {
...
private static OnItemClickListener onItemClickListener;
...
public static interface OnItemClickListener {
public void onItemClick(View view, int position);
}
...
}
我们捕获项目根视图的单击,以及当回调触发时适配器上的onClick侦听器调用。
public class ItemsAdapter extends RecyclerView.Adapter<ItemsAdapter.ViewHolder> {
...
private static OnItemClickListener onItemClickListener;
...
public static interface OnItemClickListener {
public void onItemClick(View view, int position);
}
...
public static class ViewHolder extends RecyclerView.ViewHolder {
public ImageView imageView;
public ViewHolder(View itemRootView) {
super(itemRootView);
imageView = (ImageView) itemRootView.findViewById(R.id.itemImage);
itemRootView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int position = ViewHolder.super.getAdapterPosition();
onItemClickListener.onItemClick(view,position);
}
});
}
}
}
由于活动或片段,片段在我们的情况下,我们分配一个监听器到适配器和onClick回调,我们将获得选定的项目的位置和打开一个详细的活动项目。
public class ItemsFragment extends Fragment {
...
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
...
((ItemsAdapter) adapter).setOnItemClickListener(new ItemsAdapter.OnItemClickListener() {
@Override
public void onItemClick(View view, int position) {
//Do something when an item has been clicked
}
});
...
}
...
}
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);
}
}
}
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;
}
};
这是我所做的阅读更多和下载要点在这里
在这里添加相同的内容
CustomItemClickListener.java
public interface CustomItemClickListener {
public void onItemClick(View v, int position);
}
ItemsListAdapter.java
public class ItemsListAdapter extends RecyclerView.Adapter<ItemsListAdapter.ViewHolder> {
ArrayList<ItemListSingleItem> data;
Context mContext;
CustomItemClickListener listener;
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View mView = LayoutInflater.from(parent.getContext()).inflate(R.layout.items_list_single_item, parent, false);
final ViewHolder mViewHolder = new ViewHolder(mView);
mView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
listener.onItemClick(v, mViewHolder.getAdapterPosition());
}
});
return mViewHolder;
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.itemTitle.setText(Html.fromHtml(data.get(position).getTitle()));
if (!TextUtils.isEmpty(data.get(position).getThumbnailURL())) {
// I Love picasso library :) http://square.github.io/picasso/
Picasso.with(mContext).load(data.get(position).getThumbnailURL()).error(R.drawable.ic_no_image).
placeholder(R.drawable.ic_no_image).
transform(new RoundedCornersTransformation(5, 0)).
into(holder.thumbnailImage);
} else {
holder.thumbnailImage.setImageResource(R.drawable.ic_no_image);
}
}
@Override
public int getItemCount() {
return data.size();
}
public ItemsListAdapter(Context mContext, ArrayList<ItemsListSingleItem> data, CustomItemClickListener listener) {
this.data = data;
this.mContext = mContext;
this.listener = listener;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView itemTitle;
public ImageView thumbnailImage;
ViewHolder(View v) {
super(v);
itemTitle = (TextView) v
.findViewById(R.id.post_title);
thumbnailImage = (ImageView) v.findViewById(R.id.post_thumb_image);
}
}
}
推荐文章
- 在Java中从字符串中提取数字
- 在Android中,对话框被取消或被取消有什么区别?
- 套接字的连接超时和读超时之间的区别是什么?
- 在ScrollView触摸处理中的HorizontalScrollView
- Java整数到字节数组
- 如何设置Windows环境下Java的环境变量
- Java Swing revalidate() vs repaint()
- Java中文件中的行数
- 何时在Android中使用RxJava,何时使用Android架构组件中的LiveData ?
- 如何在Android项目中使用ThreeTenABP
- 指定的子节点已经有一个父节点。你必须先在子对象的父对象上调用removeView() (Android)
- 我的Android设备没有出现在adb设备列表中
- 在没有安装apk的情况下获取Android .apk文件的VersionName或VersionCode
- Fragment onResume() & onPause()不会在backstack上被调用
- 如何设置基线对齐为假提高性能在线性布局?