in gridview checkbox is unchecked while scrolling gridview up and down

Question

I have a GridView and I have put a checkbox and imageview. The problem is that when I check this checkbox and scroll down, the checBox gets unchecked. Though the uncheck ev

Answer 1

https://groups.google.com/forum/?fromgroups#!topic/android-developers/No0LrgJ6q2M

Drawing from romain guy's solution of listview in the above link.

Your Custom Adapter must implement CompoundButton.OnCheckedChangeListener and use a SparseBooleanArray

Then

 holder.chckbx.setOnCheckedChangeListener(this);

Then

     public boolean isChecked(int position) {
        return mCheckStates.get(position, false);
    }

    public void setChecked(int position, boolean isChecked) {
        mCheckStates.put(position, isChecked);

    }

    public void toggle(int position) {
        setChecked(position, !isChecked(position));
    }
@Override
public void onCheckedChanged(CompoundButton buttonView,
        boolean isChecked) {
     mCheckStates.put((Integer) buttonView.getTag(), isChecked);    

}

Example

public class MainActivity extends Activity implements
AdapterView.OnItemClickListener {
    int count;
private CheckBoxAdapter mCheckBoxAdapter;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final GridView gridView = (GridView) findViewById(R.id.lv);
    gridView.setTextFilterEnabled(true);
    gridView.setOnItemClickListener(this);
    mCheckBoxAdapter = new CheckBoxAdapter(this);
           gridView.setAdapter(mCheckBoxAdapter);

   }

public void onItemClick(AdapterView parent, View view, int
position, long id) {
    mCheckBoxAdapter.toggle(position);
}

class CheckBoxAdapter extends ArrayAdapter implements CompoundButton.OnCheckedChangeListener
{  private SparseBooleanArray mCheckStates;
   LayoutInflater mInflater;
    ImageView imageview1,imageview;
    CheckBox cb;

    CheckBoxAdapter(MainActivity context)
    {
        super(context,0);
        mCheckStates = new SparseBooleanArray(10);
        mInflater = (LayoutInflater)MainActivity.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    }
    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return 10;
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub

        return 0;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        View vi=convertView;
        if(convertView==null)
         vi = mInflater.inflate(R.layout.checkbox, null); 
         imageview= (ImageView) vi.findViewById(R.id.textView1);

         cb = (CheckBox) vi.findViewById(R.id.checkBox1);

         cb.setTag(position);
         cb.setChecked(mCheckStates.get(position, false));
        cb.setOnCheckedChangeListener(this);
        return vi;
    }
     public boolean isChecked(int position) {
            return mCheckStates.get(position, false);
        }

        public void setChecked(int position, boolean isChecked) {
            mCheckStates.put(position, isChecked);

        }

        public void toggle(int position) {
            setChecked(position, !isChecked(position));
        }
    @Override
    public void onCheckedChanged(CompoundButton buttonView,
            boolean isChecked) {
        // TODO Auto-generated method stub
         mCheckStates.put((Integer) buttonView.getTag(), isChecked);    

    }

}

}

activity_main.xml

<RelativeLayout
     xmlns:android="http://schemas.android.com/apk/res/android" 
     android:layout_width="fill_parent" 
     android:layout_height="fill_parent">
     <GridView
     android:id="@+id/lv"
     android:layout_width="wrap_content"
     android:numColumns="2"
      android:layout_height="wrap_content"
      />

    </RelativeLayout>

checkbox.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <ImageView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="15dp"
        android:layout_marginTop="34dp"
        android:src="@drawable/ic_launcher"/>

    <CheckBox
        android:id="@+id/checkBox1"
        android:focusable="false"
        android:focusableInTouchMode="false"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/textView1"
        android:layout_marginRight="22dp"
        android:layout_marginTop="23dp" />

</RelativeLayout>

Similar to the one answered here. Instead of listview use gridview.

How to change the text of a CheckBox in listview?

Answer 2

I hit the same problem and found the solution. Hope I save a few minutes of debugging

The problem is that when I check this checkbox and scroll down, the checBox gets unchecked. Though the uncheck event is not fired, it looks unchecked.

setOnCheckedChangeListener is the wrong listener here. When the items in the gridView get recycled, the checkBoxes are reset automatically, and hence the false uncheck events as seen.

Solution : use OnClickListener instead