I am getting a ClassCastException when using two different ViewHolders
for my Groups an in ExpandableListView.
I have a separate ViewHolder for Group in position 0. The rest of the Groups use a different one.
This error happens after I already create the views by scrolling down and scroll back up to the Group in position 0.
I know my issue is in this line:
vhPropertyInfo = (ViewHolderPropertyInfo) convertView.getTag();
When I scroll back to Group position 0, it tries to cast (ViewHolderPropertyInfo) to the convertView that is not null, but it is actually (ViewHolderGroup) type. How do I resolve this?
@Override
public View getGroupView(int groupPosition, boolean isExpandable, View convertView, ViewGroup parent) {
if (groupPosition == 0) {
ViewHolderPropertyInfo vhPropertyInfo;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.row_property_info, null);
vhPropertyInfo = new ViewHolderPropertyInfo();
vhPropertyInfo.mTvName = (TextView) convertView.findViewById(R.id.tv_name);
vhPropertyInfo.mTvCountry = (TextView) convertView.findViewById(R.id.tv_country);
vhPropertyInfo.mTvCity = (TextView) convertView.findViewById(R.id.tv_city);
vhPropertyInfo.mTvDistrict = (TextView) convertView.findViewById(R.id.tv_district);
vhPropertyInfo.mTvPostalCode = (TextView) convertView.findViewById(R.id.tv_postal_code);
vhPropertyInfo.mTvStreet = (TextView) convertView.findViewById(R.id.tv_street);
vhPropertyInfo.mTvSubStreet = (TextView) convertView.findViewById(R.id.tv_sub_street);
convertView.setTag(vhPropertyInfo);
}
else {
vhPropertyInfo = (ViewHolderPropertyInfo) convertView.getTag();
}
vhPropertyInfo.mTvName.setText("House Lannister");
vhPropertyInfo.mTvCountry.setText("Westeros");
vhPropertyInfo.mTvCity.setText("Kings Landing");
vhPropertyInfo.mTvDistrict.setText("West Side");
vhPropertyInfo.mTvPostalCode.setText("12345");
vhPropertyInfo.mTvStreet.setText("123 Kings Lane");
vhPropertyInfo.mTvSubStreet.setText("Hut 23");
return convertView;
}
else {
ViewHolderGroup vhGroup;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.row_property_group, null);
vhGroup = new ViewHolderGroup();
vhGroup.mTvName = (TextView) convertView.findViewById(R.id.tv_name);
convertView.setTag(vhGroup);
}
else {
vhGroup = (ViewHolderGroup) convertView.getTag();
}
// Group 0 is property info so have to subtract one position
vhGroup.mTvName.setText(getGroup(groupPosition));
return convertView;
}
}
public final class ViewHolderGroup {
public TextView mTvName;
}
public final class ViewHolderPropertyInfo {
public TextView mTvName;
public TextView mTvCountry;
public TextView mTvCity;
public TextView mTvDistrict;
public TextView mTvPostalCode;
public TextView mTvStreet;
public TextView mTvSubStreet;
}
EDIT 1: So I fixed the problem, but checking the instance of convertView.getTag() if it was the same type of ViewHolder type, but my solution doesn't seem very elegant. Anyone know a way to do this cleaner?
@Override
public View getGroupView(int groupPosition, boolean isExpandable, View convertView, ViewGroup parent) {
if (groupPosition == 0) {
ViewHolderPropertyInfo vhPropertyInfo;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.row_property_info, null);
vhPropertyInfo = new ViewHolderPropertyInfo();
vhPropertyInfo.mTvName = (TextView) convertView.findViewById(R.id.tv_name);
vhPropertyInfo.mTvCountry = (TextView) convertView.findViewById(R.id.tv_country);
vhPropertyInfo.mTvCity = (TextView) convertView.findViewById(R.id.tv_city);
vhPropertyInfo.mTvDistrict = (TextView) convertView.findViewById(R.id.tv_district);
vhPropertyInfo.mTvPostalCode = (TextView) convertView.findViewById(R.id.tv_postal_code);
vhPropertyInfo.mTvStreet = (TextView) convertView.findViewById(R.id.tv_street);
vhPropertyInfo.mTvSubStreet = (TextView) convertView.findViewById(R.id.tv_sub_street);
convertView.setTag(vhPropertyInfo);
}
else {
if (convertView.getTag() instanceof ViewHolderPropertyInfo) {
vhPropertyInfo = (ViewHolderPropertyInfo) convertView.getTag();
}
else {
convertView = mInflater.inflate(R.layout.row_property_info, null);
vhPropertyInfo = new ViewHolderPropertyInfo();
vhPropertyInfo.mTvName = (TextView) convertView.findViewById(R.id.tv_name);
vhPropertyInfo.mTvCountry = (TextView) convertView.findViewById(R.id.tv_country);
vhPropertyInfo.mTvCity = (TextView) convertView.findViewById(R.id.tv_city);
vhPropertyInfo.mTvDistrict = (TextView) convertView.findViewById(R.id.tv_district);
vhPropertyInfo.mTvPostalCode = (TextView) convertView.findViewById(R.id.tv_postal_code);
vhPropertyInfo.mTvStreet = (TextView) convertView.findViewById(R.id.tv_street);
vhPropertyInfo.mTvSubStreet = (TextView) convertView.findViewById(R.id.tv_sub_street);
convertView.setTag(vhPropertyInfo);
}
}
vhPropertyInfo.mTvName.setText("House Lannister");
vhPropertyInfo.mTvCountry.setText("Westeros");
vhPropertyInfo.mTvCity.setText("Kings Landing");
vhPropertyInfo.mTvDistrict.setText("West Side");
vhPropertyInfo.mTvPostalCode.setText("12345");
vhPropertyInfo.mTvStreet.setText("123 Kings Lane");
vhPropertyInfo.mTvSubStreet.setText("Hut 23");
return convertView;
}
else {
ViewHolderGroup vhGroup;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.row_property_group, null);
vhGroup = new ViewHolderGroup();
vhGroup.mTvName = (TextView) convertView.findViewById(R.id.tv_name);
convertView.setTag(vhGroup);
}
else {
if (convertView.getTag() instanceof ViewHolderGroup) {
vhGroup = (ViewHolderGroup) convertView.getTag();
}
else {
convertView = mInflater.inflate(R.layout.row_property_group, null);
vhGroup = new ViewHolderGroup();
vhGroup.mTvName = (TextView) convertView.findViewById(R.id.tv_name);
convertView.setTag(vhGroup);
}
}
// Group 0 is property info so have to subtract one position
vhGroup.mTvName.setText(getGroup(groupPosition));
return convertView;
}
}
I found a more elegant way to do my solution. It is to do the
convertView.getTag()checking the instanceof the ViewHolder before the check ifconvertView == null.