Question

我有更多数据的列表视图[文本视图和复选框控件]。我将从列表视图中选择项目，并在下一个活动中显示所选项目。我的问题是，例如，如果我在列表视图中选择第20和第25项，它将在下一个活动中显示其他一些项目。 滚动时列表视图位置会发生变化。

我通过点击项目上的复选框选择项目。在checkbox.setOnChanged监听器中，我编写了选择或不选择位置的代码。如果我选择第25项并滚动列表视图，则调用getview方法，并且checkbox.setonChanged方法更改所选位置。我最后打印logcat。

我的编码格式：

public class ListContact extends ListActivity {
  public void onCreate(Bundle icicle){
    .....
    ArrayAdapter<Model> adapter = new MyCustomArrayAdapter(this,getModel());
    setListAdapter(adapter);
  }
 ....
private List<Model> getModel() {
    List<Model> list = new ArrayList<Model>();

Iterator<String> itr = constant.selectname.iterator();
    while (itr.hasNext()) {
        list.add(get(itr.next().toString()));
    }
    return list;
}

private Model get(String s) {
    return new Model(s);
}  

}

MyCustomArrayAdapter.java：

public class MyCustomArrayAdapter extends ArrayAdapter<Model> {

    private final List<Model> list;
    private final Activity context;
    constant con ;
    public MyCustomArrayAdapter(Activity context, List<Model> list) {
        super(context, R.layout.list_layout, list);
        this.context = context;
        this.list = list;
    }

    static class ViewHolder {
        protected TextView text;
        protected CheckBox checkbox;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {

//      Log.e("getview", "getview");
        View view = null;
        if (convertView == null) {
            LayoutInflater inflator = context.getLayoutInflater();
            view = inflator.inflate(R.layout.list_layout, null);
            final ViewHolder viewHolder = new ViewHolder();
            viewHolder.text = (TextView) view.findViewById(R.id.label);
            viewHolder.checkbox = (CheckBox) view.findViewById(R.id.check);
            viewHolder.checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                        public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
//                          con = new constant();
                            Model element = (Model) viewHolder.checkbox.getTag();
                            element.setSelected(buttonView.isChecked());
//                          Log.e("MyCustomArrayAdapter.java", "selectpos array list length"+constant.selectpos.size());
                            if(isChecked==true){
                                Log.e("check box value and position  ", element.getName());
                                Log.e("position", ""+position);
                                con.selectpos.set(position, 1);

                            }
                            else{
                                Log.e("position unselect", ""+position +"---------"+ element.getName());
                                con.selectpos.set(position, 0);
                            }
                        }
                    });
            view.setTag(viewHolder);
            viewHolder.checkbox.setTag(list.get(position));
        } else {
            view = convertView;
            ((ViewHolder) view.getTag()).checkbox.setTag(list.get(position));
        }
        ViewHolder holder = (ViewHolder) view.getTag();
        holder.text.setText(list.get(position).getName());
        holder.checkbox.setChecked(list.get(position).isSelected());
        return view;
    }
}

logcat结果：

02-08 10:44:28.142: E/check box value and position(293): AAAA  Qqq 
02-08 10:44:28.142: E/check box value and position(293): Mobile-123
02-08 10:44:28.152: E/position(293): 0

**after scrolling the list view some other item print 0th position unselected and wrong data:**
02-08 10:44:31.962: E/position unselect(293): 0---------F212
02-08 10:44:31.962: E/position unselect(293): Home-232

Answer 1

我解决了这个问题。我添加了

  View view = null;
  convertView = null;  //in the get view and comments the else part of
        if (convertView == null) {
                }
                /*else{
                } */

Answer 2

我建议你像这样重新调整你的getView。这帮助了我。

 @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
  ViewHolder holder =null;
//      Log.e("getview", "getview");
        View view = null;
        if (convertView == null) {
            LayoutInflater inflator = context.getLayoutInflater();
            view = inflator.inflate(R.layout.list_layout, null);
            holder =(ViewHolder) view.getTag();
            viewHolder.text = (TextView) view.findViewById(R.id.label);
            viewHolder.checkbox = (CheckBox) view.findViewById(R.id.check);

            view.setTag(viewHolder);

        } else {
            view = convertView;
            ((ViewHolder) view.getTag()).checkbox.setTag(list.get(position));
        }
    viewHolder.checkbox.setTag(list.get(position));

        holder.text.setText(list.get(position).getName());
        holder.checkbox.setChecked(list.get(position).isSelected());
          viewHolder.checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                        public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
//                          con = new constant();
                            Model element = (Model) viewHolder.checkbox.getTag();
                            element.setSelected(buttonView.isChecked());
//                          Log.e("MyCustomArrayAdapter.java", "selectpos array list length"+constant.selectpos.size());
                            if(isChecked==true){
                                Log.e("check box value and position  ", element.getName());
                                Log.e("position", ""+position);
                                con.selectpos.set(position, 1);

                            }
                            else{
                                Log.e("position unselect", ""+position +"---------"+ element.getName());
                                con.selectpos.set(position, 0);
                            }
                        }
                    });
        return view;
    }
}

Answer 3

在适配器类中更改此

View view = null;

到

View view = convertView;

列表视图位置在Android上滚动时会发生变化

3 个答案: