Question

我有一个listview支持自定义arrayadapterI写的。每个listview项都包含textview和seekbar。这背后的想法是用户应该能够移动每个搜索栏，并且应用程序存储该搜索栏的值（因此如果用户退出片段，则可以将搜索栏恢复到其正确的值）。这些值存储在一个hashmap中，其中key是权限的名称（AKA是元素的textview）

我的问题是：listview包含45个元素，但是，在第8个元素之后，我的适配器似乎认为listview回到了起点。例如：如果我移动第9个元素的搜索条然后继续向上滚动，则第1个元素将具有我给第9个元素的值。列表视图本身确实填充正确（或者似乎无论如何），因为每个元素的文本视图都不同。

这是我的自定义arrayadapter：

public class CompetenceJudgementListAdapter extends ArrayAdapter<String[]> {

private Context mContext;
private ArrayList mData;
int mLayoutResourceId;
ArrayList<CompetenceItem> mCompetenceItemList;
HashMap<String, Integer> valueList;

public CompetenceJudgementListAdapter(Context context, int resource, ArrayList<String[]> data) {
    super(context, resource, data);
    mContext = context;
    this.mLayoutResourceId = resource;
    mData = data;
    mCompetenceItemList = new ArrayList<CompetenceItem>();
    valueList = new HashMap<String, Integer>();
}

public ArrayList<String[]> getCompetenceItemData(){
    ArrayList<String[]> list = new ArrayList<String[]>();
    for(CompetenceItem item : mCompetenceItemList){
        String[] data = new String[3];
        data[0] = (String) item.title.getText();
        if(valueList.get(item.competence_id) != null){
            data[1] = String.valueOf(valueList.get(item.competence_id).toString());
        }
        data[2] = item.competence_id;
        list.add(data);
    }
    return list;
}

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

@Override
public String[] getItem(int position) {
    return null;
}

@Override
public long getItemId(int position) {
    return 0;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent){
    View row = convertView;
    CompetenceItem competenceItem = null;
    String[] measurementData = (String[]) mData.get(position);
    String c_title = measurementData[0];
    String c_id = measurementData[2];
    if (row == null) {
        LayoutInflater inflater = LayoutInflater.from(mContext);
        row = inflater.inflate(mLayoutResourceId, parent, false);
        competenceItem = new CompetenceItem();
        mCompetenceItemList.add(competenceItem);
        competenceItem.title = (TextView) row.findViewById(R.id.textview_header_competence_name);
        competenceItem.seekbar = (SeekBar) row.findViewById(R.id.seekbar_competence);
        competenceItem.seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            Integer newProgress = 0;
            String competenceId;

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

            }

            private SeekBar.OnSeekBarChangeListener init(String var) {
                competenceId = var;
                return this;
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                newProgress = seekBar.getProgress();
                valueList.put(competenceId, newProgress);
            }
        }.init(c_title));
        row.setTag(competenceItem);

    } else {
        competenceItem = (CompetenceItem) row.getTag();
    }

    competenceItem.title.setText(measurementData[0]);
    competenceItem.competence_id = measurementData[2];
    int max = SharedData.COMPETENCE_JUDGEMENT_MAX_VALUE.getIntValue();
    competenceItem.seekbar.setMax(max);
    if(measurementData[1] != null){
        String competenceValue = measurementData[1];
        competenceItem.seekbar.setProgress(Integer.parseInt(competenceValue));
    }else{
        competenceItem.seekbar.setProgress(0);
    }
    if((valueList.get(competenceItem.title.getText() )!= null)){
    competenceItem.seekbar.setProgress(valueList.get(competenceItem.title.getText()));
    }
    return row;
}

static class CompetenceItem{
    TextView title;
    SeekBar seekbar;
    String competence_id;
}

Answer 1

 if (row == null) {

        LayoutInflater inflater = LayoutInflater.from(mContext);
        row = inflater.inflate(mLayoutResourceId, parent, false);
        competenceItem = new CompetenceItem();
        mCompetenceItemList.add(competenceItem);
        competenceItem.title = (TextView) row.findViewById(R.id.textview_header_competence_name);
        competenceItem.seekbar = (SeekBar) row.findViewById(R.id.seekbar_competence);
        row.setTag(competenceItem);

    } else {
        competenceItem = (CompetenceItem) row.getTag();
    }
     competenceItem.seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            Integer newProgress = 0;
            String competenceId;

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

            }

            private SeekBar.OnSeekBarChangeListener init(String var) {
                competenceId = var;
                return this;
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                newProgress = seekBar.getProgress();
                valueList.put(competenceId, newProgress);
            }
        }.init(c_title));

我觉得这应该可行。因为这个监听器对于循环视图是相同的。

Answer 2

由回收您的观点引起的

if (row == null) {
   //******
}else {
    competenceItem = (CompetenceItem) row.getTag(); //here you are doing the recycle
}
// here you must reset your seekbar

Arrayadapter认为45个项目的列表只包含8个重复项目

2 个答案: