Use BaseAdapter to maintain the state of the checkbox in list-view when scrolling it in android


The getView() method of the class extending the BaseAdapter holds the state of the currently displayed view which is invalidated when scrolling the listview. So, in order to avoid this problem, proceed in the following manner.

 

• Create a nested class within the class (class which is extending BaseAdapter Class), namely, Viewholder.
• Declare all the views of an individual list item in this Viewholder Class.
• Create an object of this Viewholder class in the getView() method and initialize all the views declared in the Viewholder class using this object.

 

Example :

 

Activity activity;
publicclassViewHolder{
TextViewtextview;
CheckBoxcheckbox;
}
public View getView(finalint position, View convertView, ViewGroup parent)
{
View vi=convertView;
LayoutInflaterinflater = activity.getLayoutInflater();
vi = inflater.inflate (R.layout.listitem, null);
ViewHolder item=newViewHolder();
item.textview = (TextView)vi.findViewById(R.id.textview1);
item.checkbox = (CheckBox)vi.findViewById(R.id.checkbox1);
vi.setTag(item);
return vi;
}
Implement this and check the state of the checkbox while scrolling the listview.

 

 

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