java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getImportant

java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getImportantForAccessibility()' on a null object reference

getView()方法返回null,会造成这个异常

改成convertView就行

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder = null;
    if (convertView == null) {
        convertView = LayoutInflater.from(singleChoiceActivity).inflate(R.layout.single_item,null);
        holder = new ViewHolder();
        holder.tv_data = (TextView) convertView.findViewById(R.id.tv_data);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }

    holder.tv_data.setText(datas.get(position));
    return convertView;
}

static class ViewHolder {
      TextView tv_data;
}