注意：我以前在deleting all cardviews from recyclerview then adding new cardviews - adds same cardviews这里遇到过这个问题
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。
然后在我的溢出菜单中，单击显示删除列表的按钮。而且它会删除所有卡片视图，因此我的屏幕现在空白，这很好，
但是当我开始添加更多卡片视图时，我注意到它在微调器中的值与应该删除的值相同。
我在适配器中有这样的方法
public void reset() {
productList.clear();
notifyDataSetChanged();
}
就像我上面链接的问题答案一样，我尝试添加
holder.spinner.setSelection(0);
所以后来变成了
public void reset() {
holder.spinner.setSelection(0);
productList.clear();
notifyDataSetChanged();
}
但是现在它说cannot resolve symbol holder
我该怎么办？
这是我完整的 productadapter .java代码
public class ProductAdapter extends RecyclerView.Adapter<ProductAdapter.ProductViewHolder> {
private Map<Integer, Integer> mSpinnerSelectedItem = new HashMap<Integer, Integer>();
private Map<String, String> numberItemValues = new HashMap<>();
private List<Product> productList;
private Activity create;
//TODO CODE FOR CSV FILE
InputStream inputStream = null;
List<String> mSpinnerItems = null;
CSVFile csvFile = null;
//TODO END OF CODE FOR CSV FILE
public ProductAdapter(Activity activity) {
create = activity;
}
public ProductAdapter(Activity activity, List<Product> productList, Map<String, String> numberList) {
numberItemValues = numberList;
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) {
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);
String currentItem = holder.spinner.getItemAtPosition(mPosition).toString();
Set<String> set = numberItemValues.keySet(); for(String key : set) {String value = numberItemValues.get(key); Log.e("DATA ", "key = " + key + " value = " + value); }
String aisleNumber = numberItemValues.get(currentItem);
holder.textView5.setText(aisleNumber);
Log.e("SELECTION TEST", " Selected map item = " + aisleNumber );
}
@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(holder.getAdapterPosition());
notifyItemRemoved(holder.getAdapterPosition());
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();
}
public void reset() {
holder.checkBox.setChecked(false);
holder.spinner.setSelection(0);
productList.clear();
notifyDataSetChanged();
}
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){
checkBox.setChecked(false);
spinner.setSelection(0);
productList.remove(getAdapterPosition());
notifyItemRemoved(getAdapterPosition());
Toast.makeText(create, "Done!", Toast.LENGTH_LONG).show();
}
}
});
}
public View getView() {
return rootView;
}
}
//TODO CODE FOR CSV FILE
private class CSVFile {
InputStream inputStream;
public CSVFile(InputStream inputStream) {
this.inputStream = inputStream;
}
public List<String> read() {
List<String> resultList = new ArrayList<String>();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
try {
String line;
while ((line = reader.readLine()) != null) {
String[] row = line.split(",");
numberItemValues.put(row[1], row[0]);
resultList.add(row[1]);
}
} catch (IOException e) {
Log.e("Main", e.getMessage());
} finally {
try {
inputStream.close();
} catch (IOException e) {
Log.e("Main", e.getMessage());
}
}
return resultList;
}
}
}
答案 0 :(得分：0)
我认为这里的问题是recyclerview正在重用已经创建的视图。
在ViewHolder中创建一个重置方法
public void reset() {
textview5.setText("");
edittext.setText("");
// Add other variable too if needed
}
然后在设置数据之前在onBindView()中调用此方法。
@Override
public void onBindViewHolder(final ProductViewHolder holder, final int position) {
// reseting view
holder.reset();
// rest of your code...
}