我在这篇文章的帮助下以某种方式实现了回收视图，现在我的要求是在运行时从这个回收视图中删除一行。
链接-http://treyrobinson.net/blog/android-l-tutorials-part-3-recyclerview-and-cardview/
请帮帮我。
谢谢。
【问题讨论】：
标签： android android-5.0-lollipop android-recyclerview
由于我们不知道您的适配器情况如何，并且根据该链接中的信息，您可以在适配器中创建一个删除对象的方法：
public void removeItem(int position) {
mData.remove(position);
notifyItemRemoved(position);
}
您可以从您的活动中获得所有这些信息，例如：
((MyRecyclerAdapter)myRecyclerView.getAdapter()).removeItem(position);
【讨论】：
ViewHolder，正如它的名字所指出的，它只是一个视图持有者。它不应该包含任何业务逻辑或点击逻辑。它只是视图模型的映射器。
我能够让它像这样工作。
ItemTouchHelper.SimpleCallback simpleItemTouchCallback = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT) {
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int swipeDir) {
//Remove swiped item from list and notify the RecyclerView
datalist.remove(viewHolder.getAdapterPosition());
// this line animates what happens after delete
adapter.notifyItemRemoved(viewHolder.getAdapterPosition());
Snackbar.make(recyclerView, "delete successful", Snackbar.LENGTH_LONG).show();
}
@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
return false;
}
};
并像这样将上述设置为回收站视图。
ItemTouchHelper itemTouchHelper = new ItemTouchHelper(simpleItemTouchCallback);
itemTouchHelper.attachToRecyclerView(recyclerView);
【讨论】：
如果您想通过单击删除一行，我认为更简洁的方法是在 ViewHolder 上实现 onClicks。然后你在adapter上实现一个public remove方法，然后通过onCreateViewHolder方法将adapter传递给ViewHolder。
应该是这样的：
---示例---
适配器：
public class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {
private List<Object> mDataset; // This is the list of items to be shown
//Here you would write the rest of your Adapter code
public myViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
final View itemView = mInflater.inflate(R.layout.item_recyclerview_round, parent, false);
return new RoundViewHolder(itemView, this);
}
public void removeItem(int position) {
mDataSet.remove(position);
notifyItemRemoved(position);
// Add whatever you want to do when removing an Item
}
}
ViewHolder：
public class MyViewHolder RecyclerView.ViewHolder
implements View.OnClickListener {
private MyAdapter myAdapter;
// Here you would write the rest of your ViewHolder code
public MyViewHolder (View itemView, MyAdapter myAdapter){
super(itemView);
this.myAdapter = myAdapter;
// Here you would write the rest of your constructor
}
public void onClick(View view) {
myAdapter.removeItem(getAdapterPosition());
}
它对我有用。我不知道性能是否可以提高（可能），但这是我找到的最简单的方法。
希望对你有帮助。
【讨论】：
我从过去 2 天开始尝试同样的事情，终于成功了。
我的主要问题是如何获取点击视图的位置以便我们可以将其从适配器中删除？
解决方案是在onBindViewHolder 中使用holder.itemView.setTag(model.get(position)); 来存储视图的位置，并通过在onClick() 中使用ViewModel model = (ViewModel) v.getTag(); 来获取点击视图的位置
在运行时从RecyclerView 中删除行的步骤：
创建MainActivity.java
public class MainActivity extends Activity {
private RecyclerView recyclerView;
private RecyclerView.LayoutManager layoutManager;
private String[] liststring;
private TypedArray listImages;
MyRecyclerView adapter;
List<ViewModel> model;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
liststring=getResources().getStringArray(R.array.listString);
listImages=getResources().obtainTypedArray(R.array.listImages);
recyclerView=(RecyclerView) findViewById(R.id.my_recycler_view);
recyclerView.setHasFixedSize(true);
layoutManager=new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
adapter=new MyRecyclerView(createMockList(),this);
recyclerView.setAdapter(adapter);
adapter.setOnItemClickListener(new RecyclerViewItemClickInterface() {
@Override
public void onItemclick(View v,ViewModel vModel) {
// TODO Auto-generated method stub
Log.i("inflatedlayout", v.getId()+"");
adapter.remove(vModel);
}
});
}
private List<ViewModel> createMockList() {
List<ViewModel> items = new ArrayList<ViewModel>();
for (int i = 0; i < 9; i++) {
items.add(new ViewModel("Item " + (i + 1),listImages.getResourceId(i, -1)));
}
return items;
}
}
创建MyRecyclerView.java
public class MyRecyclerView extends RecyclerView.Adapter<MyRecyclerView.MyViewHolder> implements View.OnClickListener {
String data[];
TypedArray images;
MyRecyclerView mv;
Activity act_context;
RecyclerViewItemClickInterface listener;
List<ViewModel> model;
public MyRecyclerView(List<ViewModel> model,Activity act_context) {
// TODO Auto-generated constructor stub
this.model=model;
this.act_context=act_context;
}
public static class MyViewHolder extends ViewHolder{
private ImageView imageView1;
private TextView textView1;
//private IMyViewHolderClicks listener;
public MyViewHolder(View inflatedView) {
super(inflatedView);
// TODO Auto-generated constructor stub
textView1=(TextView) inflatedView.findViewById(R.id.textView1);
imageView1=(ImageView) inflatedView.findViewById(R.id.imageView1);
}
}
@Override
public int getItemViewType(int position) {
// TODO Auto-generated method stub
Log.i("getIemViewTypePosition", ""+position);
return super.getItemViewType(position);
}
@Override
public int getItemCount() {
// TODO Auto-generated method stub
return model.size();
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
// TODO Auto-generated method stub
holder.itemView.setTag(model.get(position));
holder.imageView1.setImageResource(model.get(position).getImage());
holder.textView1.setText(model.get(position).gettest());
Log.i("onBindViewHolder", "called by layoutmanager");
}
@Override
public MyViewHolder onCreateViewHolder(final ViewGroup parent, final int viewType) {
// TODO Auto-generated method stub
View v=LayoutInflater.from(act_context).inflate(R.layout.row_layout, parent, false);
v.setOnClickListener(this);
MyRecyclerView.MyViewHolder vh = new MyViewHolder(v);
Log.i("onCreateViewHolder", "ViewHolder created");
return vh;
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (listener != null) {
ViewModel model = (ViewModel) v.getTag();
listener.onItemclick(v,model);}
}
void setOnItemClickListener(RecyclerViewItemClickInterface listener){
this.listener=listener;
}
public void remove(ViewModel item) {
int position = model.indexOf(item);
model.remove(position);
notifyItemRemoved(position);
}
}
创建ViewModel.java
public class ViewModel {
String test;
int image;
public ViewModel(String test,int image) {
// TODO Auto-generated constructor stub
this.test=test;
this.image=image;
}
String gettest(){
return test;
}
int getImage(){
return image;
}}
4.创建interface：
interface RecyclerViewItemClickInterface {
void onItemclick(View v,ViewModel viewModel);
}
【讨论】：
我知道这是迟到的答案，但也许对其他人有帮助。 You don't need to add new delete method in your adapter class。最好的方法是，首先在 ViewHolder 类中使用 add interface。
public class ApapterVH extends RecyclerView.ViewHolder implements View.OnClickListener{
ImageView ivDeleteItem;
ApapterVH(View itemView) {
super(itemView);
ivDeleteItem = itemView.findViewById(R.id.ivDelete);
itemView.setOnClickListener(this);
ivDeleteFoodItem.setOnClickListener(this);
}
@Override
public void onClick(View v) {
if(v.getId() == ivDeleteItem.getId()){
onItemClickListener.onDelete(v, getAdapterPosition());
}
if(onItemClickListener!=null){
onItemClickListener.onItemClick(v, getAdapterPosition());
}
}
}
public interface OnItemClickListener {
void onItemClick(View view , int position);
void onDelete(View view, int position);
}
public void SetOnItemClickListener(final OnItemClickListener onItemClickListener){
this.onItemClickListener = onItemClickListener;
}
然后在您的 Activity 或 Fragment 中添加：
mAdapter.SetOnItemClickListener(new YourAdapter.OnItemClickListener() {
@Override
public void onItemClick(View view, int position) {
//Do something
}
@Override
public void onDelete(View view, int position) {
mList.remove(position);
mAdapter.notifyItemRemoved(position);
}
});
只有这两行代码会删除您的项目：
mList.remove(position);
mAdapter.notifyItemRemoved(position);
【讨论】：
如果上述解决方案不起作用，那么试试这个，
private fun removeItem(position: Int) {
items.removeAt(position)
notifyItemRemoved(position)
notifyItemRangeChanged(position, itemCount - position)
}
【讨论】：