Getting all checked items from listview Android

Question

I am a noobie at android programming , I am using Android studio and I have a listview item containing two textviews and a checkbox. I am trying to create a listiview with checkboxes so when a click on a specific button I will get a list the names of the checked items . Tried looking for tutorials and other helpful things but just can't get it right. Thank You everyone :) This is my custom adapter for the listview:

public class postadapter extends ArrayAdapter<post> {
ArrayList<post> list = new ArrayList<post>();
Context context;
int layoutResourceId;
post data[] = null;

public postadapter(Context context, int layoutResourceId, ArrayList<post> list) {
    super(context, layoutResourceId, list);
    this.layoutResourceId = layoutResourceId;
    this.context = context;
    this.list = list;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row = convertView;
    ViewHolder holder = null;

    if(row == null) {
        LayoutInflater inflater = ((Activity) context).getLayoutInflater();
        row = inflater.inflate(layoutResourceId, parent, false);

        holder = new ViewHolder();
        holder.txtTitle = (TextView) row.findViewById(R.id.textView1);
        holder.txtdescription = (TextView) row.findViewById(R.id.textView2);
        holder.chk = (CheckBox) row.findViewById(R.id.chkbox);

        row.setTag(holder);
        holder.chk.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                CheckBox cb = (CheckBox) v;
                post post1 = (post) cb.getTag();

                post1.setSelected(cb.isChecked());
            }
        });
    }
    else
    {
        holder = (ViewHolder)row.getTag();
    }

    post post1 = list.get(position);
    holder.txtTitle.setText(post1.getPostname());
    holder.txtdescription.setText("מספר שומרים:"+post1.getnumberguards()+" משעה: "+post1.getstime()+" עד שעה: "+post1.getetime());
holder.chk.setChecked(post1.isSelected());
    return row;
}

static class ViewHolder
{

    TextView txtTitle;
    TextView txtdescription;
    CheckBox chk;

}
 }

Answer 1

You can maintain a boolean array of all the selected checkbox-

1. Declare Boolean array in your adapter - boolean[] checkBoxState
2. Initialize it in your adapter's constructor - checkBoxState= new boolean[list.size()]

3. Then use this array in your getView method -

    holder.checkBox.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v)
    {
                   if(((CheckBox)v).isChecked())
                   {                   
                        checkBoxState[position]=true;
                       }       
                       else
                       {
                           checkBoxState[position]=false;
   
                       }
                      }
                      });
   

4. Retrieve the position from this array (Here adapter is the object of your custom adapter) -

   for(int k=0;k< adapter.checkBoxState.length ;k++) {

   if(adapter.checkBoxState[k]==true) { }`