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
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
其他回答
这就是重用View的方法。OnClickListener:
public class TestAdapter extends RecyclerView.Adapter<TestAdapter.MyviewHolder>
implements View.OnClickListener
在ViewHoder中获取项目布局的父视图:
public class MyviewHolder extends RecyclerView.ViewHolder {
LinearLayout linearLayout;
public MyviewHolder(View itemView) {
super(itemView);
linearLayout = itemView.findViewById(R.id.linear_layout_item);
}
}
在onBindViewHolder中设置标签为位置:
@Override
public void onBindViewHolder(MyviewHolder holder, int position) {
holder.linearLayout.setTag(position);
holder.linearLayout.setOnClickListener(this);
}
在你的onClick实现中:
@Override
public void onClick(View v) {
int position = (int) v.getTag();
switch (v.getId()) {
case R.id.linear_layout_item:
// do some thing with position
break;
}
}
这里有一个简单明了的方法是添加到您的ReacyclerView ViewHolder
public static class MyViewholder extends RecyclerView.ViewHolder {
public MyViewholder(View itemView) {
super(itemView);
itemView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.d("Tag", "onClick:" + getAdapterPosition());
}
});
}
}
getAdapterPosition()返回当前被单击项的位置
我的方式
活动课上:
public class MyActivity extends AppCompatActivity implements EmployeeAdapter.ClickListener {
...
@Override
public void onClick(int position) { ... }
...
}
适配器类:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
...
@Override
public void onBindViewHolder(){
holder.textView1.setOnClickListener(v -> clickListener.onClick(position));
}
...
public interface ClickListener {
void onClick(int position);
}
...
}
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();
}
});
}
}
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));
});
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