安卓：失去的EditText上滚动内容的ListView？ [英] Android :EditText loses content on scroll in ListView?

问题描述

我有一个EditText上的列表项的话，我不知道有多少项目会出现。我有一个问题，当我进入的EditText一些文本，然后向下滚动一个ListView后，我已经向上滚动再次出现在我的第一个EditText上没有文字，或者有一些文字来自其他的EditText从ListView控件。

I have list item with EditText in it, I dont 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.

我已经试过TextWatcher，并且将数据保存到数组，但问题是，返回的视图的ListView总不是正确的位置，所以我从阵列丢失一些数据。

I've tried TextWatcher, and saving data to array, but problems is that returned position of view in ListView isnt always right, so I lost some data from array.

请帮忙。

下面是我的code

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;

}

}

在这里，我已经包含了一个HashMap对象，将密切关注，如果包含的EditText值或not.And当您滚动列表视图，将再次通过一起与每个相关联的EditText文本调用它的getView方法呈现。

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.

在此code，当你首先加载列表视图，所有的EditText将是一个没有你输入一些文字text.once，将会注意到在myList.So当你再次渲染列表，文本会prevented。

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.

还有一件事，你应该实现textwatcher外，如果（convertView == NULL）..否则.. block.That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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