Force Listview not to reuse views (Checkbox)

Question

I made a custom Listview (Without overriding getView() method) with each item in a Listview having a following Layout

contactlayout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="horizontal"
  android:layout_width="match_parent"
  android:layout_height="match_parent" android:weightSum="1">
    <CheckBox android:id="@+id/checkBox1" android:text="CheckBox" android:layout_width="134dp" android:layout_height="108dp" android:focusable="false"></CheckBox>
    <LinearLayout android:id="@+id/linearLayout1" android:layout_height="match_parent" android:orientation="vertical" android:layout_width="87dp" android:layout_weight="0.84" android:weightSum="1" >
        <TextView android:text="TextView" android:layout_height="wrap_content" android:layout_width="match_parent" android:id="@+id/name" android:layout_weight="0.03"></TextView>
        <TextView android:text="TextView" android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/phone"></TextView>
        <TextView android:text="TextView" android:layout_height="wrap_content" android:layout_weight="0.03" android:layout_width="match_parent" android:id="@+id/contactid" android:visibility="invisible"></TextView>
    </LinearLayout>
</LinearLayout>

I am populating the Listview using a SimpleCursorAdapter in a following way...

Cursor c = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,null,null, ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME);

        String from[] = new String[]{ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME,ContactsContract.CommonDataKinds.Phone.NUMBER,ContactsContract.CommonDataKinds.Phone.CONTACT_ID};
        int to[] = new int[]{R.id.name,R.id.phone,R.id.contactid};
        SimpleCursorAdapter s = new SimpleCursorAdapter(this,R.layout.contactlayout,c,from,to);
        lv.setAdapter(s);

On Click of a button I am reading the states of all the Checkboxes. The problem is, if I check one CheckBox several others down the line get automatically Checked. I know this is reusing of Views. How do I avoid it ?. I am not even overriding getView() method in this case, so I wonder if there is still any way to achieve what I want?

Answer

Finally I implemented what @sastraxi suggested...

@Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View view = super.getView(position, convertView, parent);

        final CheckBox checkBox = (CheckBox) view.findViewById(R.id.checkBox1);
        final TextView name = (TextView) view.findViewById(R.id.name);
        final TextView contactId = (TextView) view.findViewById(R.id.contactid);
        final int pos = position;
        checkBox.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                if(checkBox.isChecked())
                {
                    checkList.add(String.valueOf(pos));
                    nameList.add(name.getText().toString());
                    contactList.add(contactId.getText().toString());
                    Log.i("Chk added",String.valueOf(pos));
                }
                else
                {
                    checkList.remove(String.valueOf(pos));
                    nameList.remove(name.getText().toString());
                    contactList.remove(contactId.getText().toString());
                    Log.i("Un Chk removed",String.valueOf(pos));
                }
            }
        });

        if(checkList.contains(String.valueOf(pos)))
        {
            checkBox.setChecked(true);
        }
        else
        {
            checkBox.setChecked(false);
        }

        return view;
    }

Answer 1

another way to force not reusing the views, add the following in your cursor adapter:

    @Override
    public int getItemViewType(int position) {
        return position;
    }

    @Override
    public int getViewTypeCount() {
        return 500;
    }

but yes, you should reuse views whenever possible. In my particular case, I am adding images to my views and without forcing to not reuse the view, they would get re-rendered in the reused views.

Answer 2

Ah, I see what the problem is.

Make a new class that extends SimpleCursorAdapter, say CheckboxSimpleCursorAdapter, and override getView as such:

public View getView(int position, View convertView, ViewGroup parent) {
    View view = super.getView(position, convertView, parent);
    CheckBox checkBox = (CheckBox) view.findViewById(R.id.CheckBox1);
    checkBox.setChecked(getIsThisListPositionChecked(position));
    return view;
}

As you're not using a layout whose top-level View implements Checkable, you have to do everything yourself. That includes clearing state (in this case), as the default implementation re-used a View that was checked--as you correctly intuited.

Edit: use this new code, and implement a protected boolean getIsThisListPositionChecked(int position) method that returns whether or not the item is currently checked (or something like that). I hope I'm being clear enough--you need to figure out if the item should be checked according to your model, and then set that when you create the View.