Question

我知道我的问题解决了很多Stack Overflow问题。我尝试了大部分解决方案，但没有一个成功。

我正在尝试实现listview的listrow删除。如果有两个选项delete和cancel，则会弹出listrow alert的longclick。当按下delete时，该行将被删除自定义适配器以及mysql表中的行使用异步任务。但只有最后一行被删除。

我已将notifyDataSetChanged()设置为我的适配器。即使这样，它也不能正常工作。

这是我的代码：

     listView.setOnItemLongClickListener(new OnItemLongClickListener() {

        @Override
        public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
                int position, long arg3) {
            System.out.println("postition value::" + position);
            removeItemFromList(position);

            return true;
        }
    });


    protected void removeItemFromList(int position) {
    final int deletePosition = position;
    System.out.println("deleting postition::"+deletePosition);
    AlertDialog.Builder alert = new AlertDialog.Builder(getActivity());

    alert.setTitle("Delete");
    alert.setMessage("Do you want delete this item?");
    alert.setPositiveButton("YES", new OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            // TOD O Auto-generated method stub

            // main code on after clicking yes
            new removefromfav().execute();
            courselist.remove(deletePosition);
        //  dataAdapter.remove(dataAdapter.getItem(deletePosition));
            dataAdapter.notifyDataSetChanged();
            listView.setAdapter(dataAdapter);
        //  dataAdapter.notifyDataSetInvalidated();

        }
    });
    alert.setNegativeButton("CANCEL", new OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            // TODO Auto-generated method stub
            dialog.dismiss();
        }
    });

    alert.show();

}

我的适配器类，

   private class MyCustomAdapter extends ArrayAdapter<Course> {

    private ArrayList<Course> countryList;

    public MyCustomAdapter(Context context, int textViewResourceId,
            ArrayList<Course> countryList) {
        super(context, textViewResourceId, countryList);
        this.countryList = new ArrayList<Course>();
        this.countryList.addAll(countryList);
    }

    private class ViewHolder {
        TextView code;
        TextView name;
        ImageView cover;
        TextView cost;
        ImageView ratingshow;
        ImageView promoimage;
        TextView enroll;
    }

    public void add(Course country) {

        this.countryList.add(country);
    }

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

        ViewHolder holder = null;

        if (convertView == null) {

            LayoutInflater vi = (LayoutInflater) getActivity()
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = vi.inflate(R.layout.course_overview, null);

            holder = new ViewHolder();
            holder.code = (TextView) convertView
                    .findViewById(R.id.coursename);
            holder.name = (TextView) convertView.findViewById(R.id.author);
            holder.cost = (TextView) convertView.findViewById(R.id.cost);
            holder.cover = (ImageView) convertView.findViewById(R.id.cover);
            holder.ratingshow = (ImageView) convertView
                    .findViewById(R.id.ratingimage);
            holder.promoimage = (ImageView) convertView
                    .findViewById(R.id.promoimage);
            holder.enroll = (TextView) convertView
                    .findViewById(R.id.enroll);
            convertView.setTag(holder);

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

        Course country = this.countryList.get(position);
        holder.code.setText(country.getCode());
        holder.name.setText(country.getName());
        holder.cost.setText("$ " + country.getRegion());
        holder.cover.setImageBitmap(country.getBitmap());




        return convertView;

    }

}

任何人都可以帮助我???

Answer 1

您没有从countryList中的MyCustomAdapter删除任何内容。我看到了一个添加内容的功能，但我没有看到删除内容。

添加一项功能以从countryList中删除项目：

private class MyCustomAdapter extends ArrayAdapter<Course> {

private ArrayList<Course> countryList;

public MyCustomAdapter(Context context, int textViewResourceId,
        ArrayList<Course> countryList) {
    super(context, textViewResourceId, countryList);
    this.countryList = new ArrayList<Course>();
    this.countryList.addAll(countryList);
}

private class ViewHolder {
    TextView code;
    TextView name;
    ImageView cover;
    TextView cost;
    ImageView ratingshow;
    ImageView promoimage;
    TextView enroll;
}

public void add(Course country) {

    this.countryList.add(country);
}

//ADD THIS FUNCTION
public void remove(int index) {
    this.countryList.remove(index)
}

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

    ViewHolder holder = null;

    if (convertView == null) {

        LayoutInflater vi = (LayoutInflater) getActivity()
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = vi.inflate(R.layout.course_overview, null);

        holder = new ViewHolder();
        holder.code = (TextView) convertView
                .findViewById(R.id.coursename);
        holder.name = (TextView) convertView.findViewById(R.id.author);
        holder.cost = (TextView) convertView.findViewById(R.id.cost);
        holder.cover = (ImageView) convertView.findViewById(R.id.cover);
        holder.ratingshow = (ImageView) convertView
                .findViewById(R.id.ratingimage);
        holder.promoimage = (ImageView) convertView
                .findViewById(R.id.promoimage);
        holder.enroll = (TextView) convertView
                .findViewById(R.id.enroll);
        convertView.setTag(holder);

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

    Course country = this.countryList.get(position);
    holder.code.setText(country.getCode());
    holder.name.setText(country.getName());
    holder.cost.setText("$ " + country.getRegion());
    holder.cover.setImageBitmap(country.getBitmap());




    return convertView;

}
}

并在对话框的onClick回调中调用此内容

public void onClick(DialogInterface dialog, int which) {
        // TOD O Auto-generated method stub

        // main code on after clicking yes
        new removefromfav().execute();
        dataAdapter.remove(which);
        dataAdapter.notifyDataSetChanged();

    }

Answer 2

确定我可以帮助您，您将在自定义适配器上再添加一项功能

   public void removeElementAtPosition(int position){
      this.countryList.remove(position);
      notifyDataSetChanged();
   }

并删除长按功能中的适配器项目，如

  dataAdapter.removeElementAtPosition(position);

您不想再次更新我们的适配器。您将检查并避免空指针异常

所有适配器都可以使用此功能

 public int getCount(){
     this.countryList.size();         
 }

因此，如果您使用此getcount函数 BASE ADAPTER

，您将影响此适配器中的列表，您的列表项将减少

http://developer.android.com/reference/android/widget/BaseAdapter.html

一切顺利......

从listview android中删除了错误的行

2 个答案: