文本观察器不工作

Question

我有一个listview，每行都有edittext，使用textwatcher显示内容输入的toast。该textwatcher适用于除第一行以外的所有行。输入文本后的toast在您输入文本后会一致地触发，而不是只显示一次。

其他行通过每次更改输入时显示一次toast来很好地响应所需的行为。输入的默认值为 0 。

这是我adapter getView()中的代码：

//tvItems is my edittext variable reference
TextWatcher tt = new TextWatcher() {
public void afterTextChanged(Editable s) {
                //tvItems.setSelection(s.length());
            }
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                tvItems.removeTextChangedListener(tt);
                if (tvItems.getText().toString().trim().length() == 1) {
                  //to check if input is greater than 0 so we can proceed
                    if (Integer.valueOf(tvItems.getText().toString().trim()) > 0) {
                      //displays toast
                         Toast.makeText(activity, s, Toast.LENGTH_SHORT).show();

                        tvItems.removeTextChangedListener(tt);
                    }
                }
                tvItems.addTextChangedListener(tt);
            }
        };
        tvItems.addTextChangedListener(tt);

欢迎任何建议。

根据要求，我的完整适配器代码：

public class ProductListAdapter extends BaseAdapter implements Filterable {
    List<ProductModel> mStringFilterList;
    ValueFilter valueFilter;
    int item_number = 0;
    TextWatcher tt = null;
    private Activity activity;
    private LayoutInflater inflater;
    private List<ProductModel> modelItems;
    private OnAddRemoveListener myaddInterface;
    TextView tvTitle;
    Button minusIcon, addIcon;
    public ProductListAdapter(Activity activity, List<ProductModel> modelItems, OnAddRemoveListener myaddInterface) {
        this.activity = activity;
        this.modelItems = modelItems;
        mStringFilterList = modelItems;
        this.myaddInterface = myaddInterface;
    }
    @Override
    public int getCount() {
        return modelItems.size();
    }
    @Override
    public Object getItem(int location) {
        return modelItems.get(location);
    }
    @Override
    public long getItemId(int position) {
        return position;
    }/*
    @Override
    public boolean isEnabled(int position) {
        return false;
    }*/
    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        if (inflater == null)
            inflater = (LayoutInflater) activity
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        if (convertView == null)
            convertView = inflater.inflate(R.layout.product_item_row, null);
        final ProductModel m = modelItems.get(position);
        tvTitle = (TextView) convertView.findViewById(R.id.tv2);
        TextView tprice = (TextView) convertView.findViewById(R.id.tv3);
        boolean ignoreNextTextChange = true;
        final EditText tvItems = (EditText) convertView.findViewById(R.id.num);
        tvItems.setText("0");
        minusIcon = (Button) convertView.findViewById(R.id.minus);
        addIcon = (Button) convertView.findViewById(R.id.add);
        //add items
        addIcon.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.d("add button", "clicked");
                int new_item_number = 1 + Integer.parseInt(tvItems.getText().toString());
                tvItems.setText("" + new_item_number);
                (myaddInterface).onItemadded(String.valueOf(m.getPrice()), new_item_number, position);
            }
        });
        minusIcon.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.d("minus button", "clicked");
                int new_item_number = Integer.parseInt(tvItems.getText().toString());
                if (new_item_number > 0) {
                    (myaddInterface).onItemremoved(String.valueOf(m.getPrice()), position);
                    tvItems.setText("" + (new_item_number - 1));
                } else if (tvItems.getText().toString().equals("0")) {
                    tvItems.setText("0");
                }
            }
        });
        tvTitle.setText(m.getname());
        tprice.setText("(" + m.getPrice() + ")");
    public void afterTextChanged(Editable s) {
        if (tvItems.getText().toString().trim().length() == 1) { 
 
            //to check if input is greater than 0 so we can proceed 
            if (Integer.valueOf(tvItems.getText().toString().trim()) > 0) {
               //displays toast 
               Toast.makeText(activity, s, Toast.LENGTH_SHORT).show();    
            } 
         } 
    } 
 
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    } 
 
    public void onTextChanged(CharSequence s, int start, int before, int count) {
    } 
}; 
        tvItems.addTextChangedListener(tt);
        return convertView;
    }
    //code for search filter, not associated with the question
    
    @Override
    public Filter getFilter() {
        if (valueFilter == null) {
            valueFilter = new ValueFilter();
        }
        return valueFilter;
    }
    private class ValueFilter extends Filter {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults results = new FilterResults();
            if (constraint != null && constraint.length() > 0) {
                ArrayList<ProductModel> filterList = new ArrayList<>();
                for (int i = 0; i < mStringFilterList.size(); i++)
                    if ((mStringFilterList.get(i).getname().toUpperCase())
                            .contains(constraint.toString().toUpperCase()) || (mStringFilterList.get(i).getproductDesc().toUpperCase())
                            .contains(constraint.toString().toUpperCase())) {
                        ProductModel m = new ProductModel(mStringFilterList.get(i)
                                .getProduct_id(), mStringFilterList.get(i)
                                .getname(), mStringFilterList.get(i)
                                .getPrice(), mStringFilterList.get(i)
                                .getimage_url(), mStringFilterList.get(i)
                                .getproductDesc());
                        filterList.add(m);
                    }
                results.count = filterList.size();
                results.values = filterList;
            } else {
                results.count = mStringFilterList.size();
                results.values = mStringFilterList;
                //show no results
            }
           /* }else if((mStringFilterList.get(i).getproductDesc().toUpperCase())
                    .contains(constraint.toString().toUpperCase())){}*/
            return results;
        }
        @Override
        protected void publishResults(CharSequence constraint,
                                      FilterResults results) {
            modelItems = (List<ProductModel>) results.values;
            notifyDataSetChanged();
        }
    }
}

Answer 1

将侦听器对象设置为edittext，（即tt），像 这样

editText.addTextChangedListener（tt）;

Answer 2

你能试试这个吗：

TextWatcher tt = new TextWatcher() {
    public void afterTextChanged(Editable s) {
        if (tvItems.getText().toString().trim().length() == 1) {
            //to check if input is greater than 0 so we can proceed
            if (Integer.valueOf(tvItems.getText().toString().trim()) > 0) {
               //displays toast
               Toast.makeText(activity, s, Toast.LENGTH_SHORT).show();    
            }
         }
    }
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }
    public void onTextChanged(CharSequence s, int start, int before, int count) {
    }
};