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?
而不是实现接口视图。OnClickListener内部视图持有人或创建和接口和实现接口在您的活动..
我使用这段代码简单的OnClickListener实现。
public static class SimpleStringRecyclerViewAdapter
extends RecyclerView.Adapter<SimpleStringRecyclerViewAdapter.ViewHolder> {
// Your initializations goes here...
private List<String> mValues;
public static class ViewHolder extends RecyclerView.ViewHolder {
//create a variable mView
public final View mView;
/*All your row widgets goes here
public final ImageView mImageView;
public final TextView mTextView;*/
public ViewHolder(View view) {
super(view);
//Initialize it here
mView = view;
/* your row widgets initializations goes here
mImageView = (ImageView) view.findViewById(R.id.avatar);
mTextView = (TextView) view.findViewById(android.R.id.text1);*/
}
}
public String getValueAt(int position) {
return mValues.get(position);
}
public SimpleStringRecyclerViewAdapter(Context context, List<String> items) {
mBackground = mTypedValue.resourceId;
mValues = items;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.list_item, parent, false);
view.setBackgroundResource(mBackground);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(final ViewHolder holder, int position) {
holder.mBoundString = mValues.get(position);
holder.mTextView.setText(mValues.get(position));
//Here it is simply write onItemClick listener here
holder.mView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Context context = v.getContext();
Intent intent = new Intent(context, ExampleActivity.class);
context.startActivity(intent);
}
});
}
@Override
public int getItemCount() {
return mValues.size();
}
}
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)
})
如果你想添加onClick()到项目的子视图，例如，项目中的按钮，我发现你可以很容易地在你自己的RecyclerView的onCreateViewHolder()中做到这一点。适配器就像这样:
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater
.from(parent.getContext())
.inflate(R.layout.cell, null);
Button btn = (Button) v.findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//do it
}
});
return new MyViewHolder(v);
}
我不知道这是不是一个好方法，但它很有效。如果有人有更好的想法，很高兴告诉我并纠正我的答案!：）
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
}
});
