EditText 在 ListView 中滚动时丢失内容? [英] EditText loses content on scroll in ListView?

问题描述

我有一个带有 EditText 的列表项，我不知道会有多少项.当我在 EditText 中输入一些文本，然后向下滚动 ListView 时遇到问题，再次向上滚动后，我的第一个 中没有文本EditText，或者有一些来自 ListView 的其他 EditText 的文本.

I have list item with EditText in it, I don't know how many items there will be. I have a problem when I enter some text in EditText, and then scroll down a ListView, after I've scroll up again there is no text in my first EditText, or there is some text from other EditText from ListView.

我尝试过 TextWatcher，并将数据保存到数组，但问题是 ListView 中返回的视图位置并不总是正确的，所以我丢失了一些数据来自数组.

I've tried TextWatcher, and saving data to array, but problems is that returned position of view in ListView isn't always right, so I lost some data from array.

这是我的代码:

public class EfficientAdapter extends BaseAdapter {

    private LayoutInflater mInflater;
    public String[] Current;
    ArrayList<String> MeterName, PreviousReading, Current_Reading;
    JSONArray getArray_Meter_Reading;

    public EfficientAdapter(Context context, JSONArray getArray_Meter_Reading) {
        mInflater = LayoutInflater.from(context);
        this.getArray_Meter_Reading = getArray_Meter_Reading;
        MeterName = new ArrayList<String>();
        PreviousReading = new ArrayList<String>();
        for (int i = 0; i < getArray_Meter_Reading.length(); i++) {
            try {
                String Meter_Name = getArray_Meter_Reading.getJSONObject(i)
                        .getString("MeterName").toString();
                String previous_Meter_Reading = getArray_Meter_Reading
                        .getJSONObject(i).getString("PrevMeterReading")
                        .toString();
                MeterName.add(Meter_Name);
                PreviousReading.add(previous_Meter_Reading);

                // Meter[i]=MeterName.get(i);
                // Previous[i]=PreviousReading.get(i);
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    public int getCount() {

        return getArray_Meter_Reading.length();
    }

    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        final ViewHolder holder;

        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.meter_reading_list, null);
            holder = new ViewHolder();
            holder.adp_MeterName = (TextView) convertView
                    .findViewById(R.id.txt_Meter_Name);
            holder.adp_Previous = (TextView) convertView
                    .findViewById(R.id.txt_Previous);
            holder.adp_Current = (EditText) convertView
                    .findViewById(R.id.ed_Current);

            holder.adp_Current.addTextChangedListener(new TextWatcher() {

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

                }

                public void beforeTextChanged(CharSequence s, int start,
                        int count, int after) {
                    // TODO Auto-generated method stub

                }

                public void afterTextChanged(Editable s) {

                    Current[holder.ref] = s.toString();

                }
            });
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.ref = position;
        holder.adp_MeterName.setText(MeterName.get(position));
        holder.adp_Previous.setText(PreviousReading.get(position));
        // holder.adp_Current.setHint(MeterName.get(position));

        // holder.adp_Current.setText(PreviousReading.get(position));

        return convertView;
    }

    class ViewHolder {
        TextView adp_MeterName, adp_Previous;
        EditText adp_Current;
        int ref;

    }

}

推荐答案

试试这个:

public class EfficientAdapter extends BaseAdapter {

private LayoutInflater mInflater;
public String[] Current;
ArrayList<String> MeterName, PreviousReading, Current_Reading;
JSONArray getArray_Meter_Reading;
public static HashMap<Integer,String> myList=new HashMap<Integer,String>();

public EfficientAdapter(Context context, JSONArray getArray_Meter_Reading) {
    mInflater = LayoutInflater.from(context);
    this.getArray_Meter_Reading = getArray_Meter_Reading;
    MeterName = new ArrayList<String>();
    PreviousReading = new ArrayList<String>();

    for (int i = 0; i < getArray_Meter_Reading.length(); i++) {
        try {
            String Meter_Name = getArray_Meter_Reading.getJSONObject(i)
                    .getString("MeterName").toString();
            String previous_Meter_Reading = getArray_Meter_Reading
                    .getJSONObject(i).getString("PrevMeterReading")
                    .toString();
            MeterName.add(Meter_Name);
            PreviousReading.add(previous_Meter_Reading);

            // Meter[i]=MeterName.get(i);
            // Previous[i]=PreviousReading.get(i);
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    // initialize myList
    for(int i=0;i<JSON_ARRAY_LENGTH;i++)
    {
       myList.put(i,"");
    }
}

public int getCount() {

    return getArray_Meter_Reading.length();
}

public Object getItem(int position) {
    // TODO Auto-generated method stub
    return position;
}

public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;
}

public View getView(int position, View convertView, ViewGroup parent) {
    final ViewHolder holder;
    final int pos=position;
    if (convertView == null) {
        convertView = mInflater.inflate(R.layout.meter_reading_list, null);
        holder = new ViewHolder();
        holder.adp_MeterName = (TextView) convertView
                .findViewById(R.id.txt_Meter_Name);
        holder.adp_Previous = (TextView) convertView
                .findViewById(R.id.txt_Previous);
        holder.adp_Current = (EditText) convertView
                .findViewById(R.id.ed_Current);


        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }
     holder.adp_Current.addTextChangedListener(new TextWatcher() {

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

            }

            public void beforeTextChanged(CharSequence s, int start,
                    int count, int after) {
                // TODO Auto-generated method stub

            }

            public void afterTextChanged(Editable s) {

                Current[holder.ref] = s.toString();
                myList.put(pos,s.toString.trim());
            }
        });
    holder.ref = position;
    holder.adp_MeterName.setText(MeterName.get(position));
    holder.adp_Previous.setText(PreviousReading.get(position));
    // holder.adp_Current.setHint(MeterName.get(position));

    // holder.adp_Current.setText(PreviousReading.get(position));

    holder.adp_Current.setText(myList.get(position));

    return convertView;
}

class ViewHolder {
    TextView adp_MeterName, adp_Previous;
    EditText adp_Current;
    int ref;

}

}

这里我包含了一个 HashMap 对象，它将密切关注 EditText 是否包含值.当您滚动列表视图时，它将通过调用其 getView 方法以及与每个编辑文本关联的文本再次呈现.

Here I have included a HashMap object which will keep an eye on if EditText contains value or not.And when you scroll the listview,it will be rendered again by calling its getView method along with the text associated with each edittext.

在这段代码中，当您第一次加载列表视图时，您的所有编辑文本都将没有文本.一旦您输入了一些文本，它就会被记录在 myList 中.因此，当您再次渲染列表时，您的文本将被阻止.

In this code,when you firstly load listview,all your edittext will be with no text.once you enter some text,it will be noted in myList.So when you again render the list,your text would be prevented.

还有一点，你应该在 if(convertView==null)..else.. 块之外实现 textwatcher.这是一个更好的做法！

One more thing,you should implement textwatcher outside if(convertView==null)..else.. block.That's a better practice!

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