ListView为啥滚动listView时edittext数据丢失

Posted 2023-02-22

【中文标题】ListView为啥滚动listView时edittext数据丢失

【英文标题】：ListView Why edittext data lost when scroll listViewListView为什么滚动listView时edittext数据丢失

【发布时间】：2014-10-06 11:19:16

【问题描述】：

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

【问题讨论】：

阅读***.com/questions/11945563/…了解原因

你应该从写它的人那里了解视图回收：涡轮增压你的 UI：google.com/events/io/2009/sessions/…

是的，我知道问题所在，我将数据存储在 HashMap 中并再次调用它，但它仍然错误:(

@kemdo 我认为您需要在更改对象 DishEntity

后保存 editText 值

【参考方案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。

【讨论】：

谢谢你，我通过将数据放入hashmap（数据=位置和文本）来存储数据，然后通过Edittext Settext（HashMap.getPosition）再次调用它，但它仍然错误:(