ListView为什么滚动listView时edittext数据丢失

Question

我在几页中遵循了一些代码，但它不起作用。这是我的 pageAdapter 代码：

public class ViewHolder {
    int ref;
    TextView txtTimeToEat;
    LinearLayout lnlDishListView, lnlDishToGetpos;
    ImageView imgDish;
    TextView txtDishName;
    TextView txtDishWhen;
    TextView txtActiGoal;
    TextView txtActiActual;
    EditText edtDishAtual;
}

public SelectDishActualAdapter(Context context, List<DishEntity> listDishInTime) {

    mContext = context;
    Current = new String[listDishInTime.size()];
    this.listDishInTime = listDishInTime;
    inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public int getCount() {
    return listDishInTime.size();
}

@Override
public Object getItem(int position) {
    return listDishInTime.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView( int position, View convertView, ViewGroup parent) {
    View vi = convertView;
    final int pos = position;
    if (vi == null) {
        vi = inflater.inflate(R.layout.update_actual_dish_custom, null);
        holder = new ViewHolder();
        holder.lnlDishListView = (LinearLayout) vi.findViewById(R.id.lnlDishListView);
        holder.lnlDishToGetpos = (LinearLayout) vi.findViewById(R.id.lnlDishToGetPos);
        holder.txtTimeToEat = (TextView) vi.findViewById(R.id.txtEatTime);
        holder.imgDish = (ImageView) vi.findViewById(R.id.imgDishActual);
        holder.txtDishName = (TextView) vi.findViewById(R.id.txtDishActualName);
        holder.txtActiGoal = (TextView) vi.findViewById(R.id.txtManualGram);
        holder.txtActiActual = (TextView) vi.findViewById(R.id.txtActualGram);
        holder.edtDishAtual = (EditText) vi.findViewById(R.id.edtActualGram);
        holder.edtDishAtual.setId(pos);
        vi.setTag(holder);
    } else {
        holder = (ViewHolder) vi.getTag();
    }

    ///// id = 989898,989897,989896 is to decrale footer,It is mean  Breakfast,Lunch and Dinner
    if (listDishInTime.get(position).getDishId() == 989898) {
        holder.txtTimeToEat.setText(mContext.getResources().getString(R.string.sang));
        holder.txtTimeToEat.requestLayout();
        holder.txtTimeToEat.getLayoutParams().height = 40;
        holder.lnlDishListView.requestLayout();
        holder.lnlDishListView.getLayoutParams().height = 0;

    } else if (listDishInTime.get(position).getDishId() == 989897) {
        holder.txtTimeToEat.setText(mContext.getResources().getString(R.string.trua));
        holder.txtTimeToEat.requestLayout();
        holder.txtTimeToEat.getLayoutParams().height = 40;
        holder.lnlDishListView.requestLayout();
        holder.lnlDishListView.getLayoutParams().height = 0;
    } else if (listDishInTime.get(position).getDishId() == 989896) {
        holder.txtTimeToEat.setText(mContext.getResources().getString(R.string.chieu));
        holder.txtTimeToEat.requestLayout();
        holder.txtTimeToEat.getLayoutParams().height = 40;
        holder.lnlDishListView.requestLayout();
        holder.lnlDishListView.getLayoutParams().height = 0;
    } else {
        // Otherwise fill to listview with custom data
        String temp = listDishInTime.get(position).getImageUrl();
        final int imgID = mContext.getResources().getIdentifier(temp, "drawable", mContext.getPackageName());
        holder.txtDishName.setText(listDishInTime.get(position).getName());
        holder.imgDish.setImageResource(imgID);
        int size = holder.imgDish.getLayoutParams().width;

        holder.txtTimeToEat.requestLayout();
        holder.txtTimeToEat.getLayoutParams().height = 0;
        holder.lnlDishListView.requestLayout();
        holder.lnlDishListView.getLayoutParams().height = size;

        holder.edtDishAtual.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void afterTextChanged(Editable s) {
                holder.ref = pos;
                Current[holder.ref] = s.toString(); // String[] Current with size = new size
                myList.put(pos, s.toString().trim()); //mylist is hashmap
            }
        });
        holder.edtDishAtual.setText(myList.get(pos));
    }
    return vi;
}

但是当我滚动时，editext 仍然会丢失内容数据 :(。请帮帮我

Answer 1

ListView 回收它的子元素以优化内存的使用。当您的 EditText 项目移出屏幕时，它会被列表中的另一个项目使用。

这个来自 Udacity Android 课程的short video 很好地解释了它是如何工作的。只需 1:40 分钟。

如果您希望您的 EditText 保留文本，您必须自己将其存储在项目数据中，然后在您的项目再次显示时恢复它。