当用户按下FAB时，卡片视图将添加到回收站视图。每个Cardview内部都有一个复选框。我要这样做，以便当用户在特定卡片视图中打勾时，该特定卡片视图被删除。
（仅供参考，每个Cardview都有一个微调框和一个复选框，以及一个textview和edittext）
我按了4次fab键，以将4张卡片视图添加到屏幕上。然后，我从微调器中挑选了不同的东西，看看发生了什么。当我勾选复选框时，该cardview将删除。我在所有卡片视图的复选框中打了勾，直到没有卡片视图为止。
但是当我按下晶圆厂以添加新的cardview时，我注意到cardview具有相同的选定微调器值，并且该复选框已被选中。例如，说我首先有一个带有“土豆”的卡片视图，然后在其上打勾。现在屏幕上什么也没有。然后我按fab添加cardview。然后，我看到cardview上带有wlel的“ potatoes”，并且勾选了该复选框。.如果那没有道理，请要求澄清
该怎么办？
ProductAdapter.java
public class ProductAdapter extends RecyclerView.Adapter<ProductAdapter.ProductViewHolder> {
private Map<Integer, Integer> mSpinnerSelectedItem = new HashMap<Integer, Integer>();
//this context we will use to inflate the layout
//Remove this..Please
// CheckBox checkBox;
//private Context mCtx;
private SearchableSpinner spinner;
//we are storing all the products in a list
private List<Product> productList;
private Activity create;
public ProductAdapter(Activity activity) {
create = activity;
}
//getting the context and product list with constructor
public ProductAdapter(Activity activity, List<Product> productList) {
// this.mCtx = mCtx;
create = activity;
this.productList = productList;
}
@Override
public ProductViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//inflating and returning our view holder
LayoutInflater inflater = LayoutInflater.from(create);
View view = inflater.inflate(R.layout.layout_products, null);
return new ProductViewHolder(view);
}
@Override
public void onBindViewHolder(final ProductViewHolder holder, final int position) {
// //getting the product of the specified position
ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(create, R.layout.item_spinner_layout,
Product.getSpinnerItemsList());
spinnerArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
holder.spinner.setAdapter(spinnerArrayAdapter);
holder.spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int mPosition, long id) {
mSpinnerSelectedItem.put(position, mPosition);
TextView mTextView = view.findViewById(R.id.mSpinnerText);
/* Toast.makeText(create, "Selected Item: " + mTextView.getText().toString(), Toast.LENGTH_LONG).show();
Log.e("***************", "Selected Item: " + mTextView.getText().toString());*/
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
//binding the data with the viewholder views
if (mSpinnerSelectedItem.containsKey(position)) {
holder.spinner.setSelection(mSpinnerSelectedItem.get(position));
}
holder.getView().setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(create);
// set title
alertDialogBuilder.setTitle("Delete Item");
// set dialog message
alertDialogBuilder
.setMessage("Are you sure you want to delete this item?")
.setCancelable(false)
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// if this button is clicked, close
// current activity
holder.checkBox.setChecked(false);
holder.spinner.setSelection(0);
productList.remove(position);
notifyItemRemoved(position);
Toast.makeText(create, "Item removed.", Toast.LENGTH_LONG).show();
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// if this button is clicked, just close
// the dialog box and do nothing
dialog.cancel();
}
});
// create alert dialog
AlertDialog alertDialog = alertDialogBuilder.create();
// show it
alertDialog.show();
}
});
}
@Override
public int getItemCount() {
return productList.size();
}
class ProductViewHolder extends RecyclerView.ViewHolder {
SearchableSpinner spinner;
EditText editText;
TextView textView5;
CheckBox checkBox;
LinearLayout linearLayout;
View rootView;
public ProductViewHolder(View itemView) {
super(itemView);
spinner = itemView.findViewById(R.id.spinner);
editText = itemView.findViewById(R.id.editText);
textView5 = itemView.findViewById(R.id.textView5);
checkBox = itemView.findViewById(R.id.checkBox);
rootView = itemView.findViewById(R.id.linearLayout);
checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// makes the set disappear when checkbox is ticked.
if(isChecked){
holder.checkBox.setChecked(false);
holder.spinner.setSelection(0);
productList.remove(getAdapterPosition());
notifyItemRemoved(getAdapterPosition());
Toast.makeText(create, "Done!", Toast.LENGTH_LONG).show();
}
}
});
}
public View getView() {
return rootView;
}
}
}
答案 0 :(得分：2)
RecyclerView回收ViewHolders的性能。
这意味着，如果在微调器中选择了“ ViewHolder A”，则即使您从列表中删除该项目，它也不会被破坏。当您将新项目添加到列表中时，您的RecyclerView可能会对该项目重复使用“ ViewHolder A”，并且选择的内容与上一个项目相同（删除之前）。
为避免这种情况，请在使用findViewByPosition的{{1}}方法将新项目添加到列表中时手动更新UI。
示例：
LayoutManager如果您想将所有// FAB button onClick method:
public void onClick(View v) {
// Add item to RecyclerView list
int itemPosition = myRecyclerViewAdapter.itemList.indexOf(newItem);
ProductViewHolder vh = ((ProductViewHolder)recyclerView.getLayoutManager().findViewByPosition(itemPosition));
// Here, set everything to the default values (unchecked checkbox, etc)
}
相关代码保留在适配器中（我鼓励您这样做），则可以在删除项目后将RecyclerView UI更新为默认值（而不是添加一个）时，您的ViewHolder就很新鲜，可以用于下一项了。
示例（更好地使用此解决方案）：
ViewHolder