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
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;
}
}
其他回答
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);
}
...
}
您可以将clickListener传递给适配器。
在活动中:
private View.OnClickListener mItemClick = new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = null;
int position = list.getChildPosition(v);
switch (position) {
case 0:
intent = new Intent(MainActivity.this, LeakCanaryActivity.class);
break;
case 1:
intent = new Intent(MainActivity.this, ButterKnifeFragmentActivity.class);
break;
}
if (intent != null) {
MainActivity.this.startActivity(intent);
}
}
};
然后将它传递给适配器:
MainAdapter mainAdapter = new MainAdapter(this, mItemClick);
在适配器的onCreateViewHolder中:
@Override
public MainAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int position) {
View itemView = activity.getLayoutInflater().inflate(R.layout.main_adapter_item, viewGroup, false);
ViewHolder holder = new ViewHolder(itemView);
itemView.setOnClickListener(mItemClick);
return holder;
}
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
}
});
...
}
...
}
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));
});
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);
}
}
}
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