从顶部滚动到底部时，Listview图像变得混乱

Question

I have a custom list view adapter, and when I scroll down/up the list, images get shuffled and I don't know what to do. How to solve this problem?

public View getView(int position, View convertView, ViewGroup parent) {
    DataModel dataModel = getItem(position);
    ViewHolder viewHolder;
    if (convertView == null) {

      convertView=LayoutInflater.from(mContext).inflate(R.layout.list_item, parent, false);

        viewHolder = new ViewHolder();
        viewHolder.letter = convertView.findViewById(R.id.tvFirstt);
        viewHolder.name = convertView.findViewById(R.id.nameview);
        viewHolder.contact =convertView.findViewById(R.id.contactview);
        viewHolder.profileimg=convertView.findViewById(R.id.profileimg);
        viewHolder.chkSelect = convertView.findViewById(R.id.checkbox);
        viewHolder.detail = convertView.findViewById(R.id.detail);
    } else {
        viewHolder = (ViewHolder) convertView.getTag();

    }


        viewHolder.name.setText(dataModel.fname + " " + dataModel.lname);
        viewHolder.contact.setText(dataModel.landline);
        viewHolder.detail.setImageResource(R.drawable.right);
        viewHolder.chkSelect.setTag(position);
        viewHolder.chkSelect.setChecked(dataModel.isChecked);

        viewHolder.chkSelect.setOnCheckedChangeListener(this);
        if (dataModel.image == null) {
            viewHolder.letter.setVisibility(View.VISIBLE);
            viewHolder.letter.setText(dataModel.fname.substring(0, 1));
        } else {
            viewHolder.profileimg.setVisibility(View.VISIBLE);
            viewHolder.profileimg.setImageBitmap(convertToBitmap(dataModel.image));
        }

    } else {
        Log.e("Error", "Please see again");
    }

    convertView.setTag(viewHolder);
    return convertView;
}

Answer 1

you were not resetting the image

public View getView(int position, View convertView, ViewGroup parent) {
    DataModel dataModel = getItem(position);
    ViewHolder viewHolder;
    if (convertView == null) {

      convertView=LayoutInflater.from(mContext).inflate(R.layout.list_item, parent, false);

        viewHolder = new ViewHolder();
        viewHolder.letter = convertView.findViewById(R.id.tvFirstt);
        viewHolder.name = convertView.findViewById(R.id.nameview);
        viewHolder.contact =convertView.findViewById(R.id.contactview);
        viewHolder.profileimg=convertView.findViewById(R.id.profileimg);
        viewHolder.chkSelect = convertView.findViewById(R.id.checkbox);
        viewHolder.detail = convertView.findViewById(R.id.detail);
    } else {
        viewHolder = (ViewHolder) convertView.getTag();

    }


        viewHolder.name.setText(dataModel.fname + " " + dataModel.lname);
        viewHolder.contact.setText(dataModel.landline);
        viewHolder.detail.setImageResource(R.drawable.right);
        viewHolder.chkSelect.setTag(position);
        viewHolder.chkSelect.setChecked(dataModel.isChecked);

        viewHolder.chkSelect.setOnCheckedChangeListener(this);
        if (dataModel.image == null) {
            viewHolder.letter.setVisibility(View.VISIBLE);
            viewHolder.letter.setText(dataModel.fname.substring(0, 1));
            //I have added this
            viewHolder.profileimg.setImageBitmap(null);
        } else {
            viewHolder.profileimg.setVisibility(View.VISIBLE);
            viewHolder.profileimg.setImageBitmap(convertToBitmap(dataModel.image));
        }

    } else {
        Log.e("Error", "Please see again");
    }

    convertView.setTag(viewHolder);
    return convertView;
}