Develop Reference

ListView to RecyclerView conversion, problem in converting get View method

I want to convert Listview to RecyclerView in my app, I tried to convert code but stucked at getView method, can any one explain how to use this getView code in Recylcer view.
Adapter for ListView CardAdapter.java
public class CardAdapter extends ArrayAdapter<CardDataModel> {
private Context context;
List<CardDataModel> cards;
SharedPreference sharedPreference;
public CardAdapter(Context context, List<CardDataModel> cards) {
super(context, R.layout.card_list_item, cards);
this.context = context;
this.cards = cards;
sharedPreference = new SharedPreference();
}
private class ViewHolder {
TextView CardNameTxt;
TextView CardDescTxt;
TextView CardPriceTxt;
ImageView favoriteImg;
}
#Override
public int getCount() {
return cards.size();
}
#Override
public CardDataModel getItem(int position) {
return cards.get(position);
}
#Override
public long getItemId(int position) {
return 0;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.card_list_item, null);
holder = new ViewHolder();
holder.CardNameTxt = (TextView) convertView
.findViewById(R.id.txt_crd_name);
holder.CardDescTxt = (TextView) convertView
.findViewById(R.id.txt_crd_desc);
holder.CardPriceTxt = (TextView) convertView
.findViewById(R.id.txt_crd_no);
holder.favoriteImg = (ImageView) convertView
.findViewById(R.id.imgbtn_favorite);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
CardDataModel card = (CardDataModel) getItem(position);
holder.CardNameTxt.setText(card.getName());
holder.CardDescTxt.setText(card.getDescription());
holder.CardPriceTxt.setText(card.getPrice() + " ");
/*If a product exists in shared preferences then set heart_red drawable
* and set a tag*/
if (checkFavoriteItem(card)) {
holder.favoriteImg.setImageResource(R.drawable.heart_red);
holder.favoriteImg.setTag("red");
} else {
holder.favoriteImg.setImageResource(R.drawable.heart_grey);
holder.favoriteImg.setTag("grey");
}
return convertView;
}
public boolean checkFavoriteItem(CardDataModel checkCard) {
boolean check = false;
List<CardDataModel> favorites = sharedPreference.getFavorites(context);
if (favorites != null) {
for (CardDataModel card : favorites) {
if (card.equals(checkCard)) {
check = true;
break;
}
}
}
return check;
}
#Override
public void add(CardDataModel card) {
super.add(card);
cards.add(card);
notifyDataSetChanged();
}
#Override
public void remove(CardDataModel card) {
super.remove(card);
cards.remove(card);
notifyDataSetChanged();
}
}
converted somecode like this in RecyclerView Adapter ... CardRvAdapter.java
public class CardRvAdapter extends RecyclerView.Adapter<CardRvAdapter.MyViewHolder> {
private Context context;
List<CardDataModel> cards;
SharedPreference sharedPreference;
public CardRvAdapter(Context context, List<CardDataModel> cards) {
this.context = context;
this.cards = cards;
sharedPreference = new SharedPreference(); }
#Override
public int getItemCount() {
return cards.size();
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
// on create view holder code
View view;
LayoutInflater mInflater = LayoutInflater.from(context);
view = mInflater.inflate(R.layout.card_list_item, viewGroup,false);
return new MyViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull MyViewHolder myViewHolder, int i) {
//on bind view holder code
myViewHolder.CardPriceTxt.setText(cards.get(i).getPrice());
myViewHolder.CardNameTxt.setText(cards.get(i).getName());
myViewHolder.CardDescTxt.setText(cards.get(i).getDescription());
if (checkFavoriteItem(card)) {
myViewHolder.favoriteImg.setImageResource(R.drawable.heart_red);
myViewHolder.favoriteImg.setTag("red");
} else {
myViewHolder.favoriteImg.setImageResource(R.drawable.heart_grey);
myViewHolder.favoriteImg.setTag("grey");
} }
// checking for favotites in shared preferences
public boolean checkFavoriteItem(CardDataModel checkCard) {
boolean check = false;
List<CardDataModel> favorites = sharedPreference.getFavorites(context);
if (favorites != null) {
for (CardDataModel card : favorites) {
if (card.equals(checkCard)) {
check = true;
break;
}
}
}
return check;
}
#Override
public void add(CardDataModel card) {
super.add(card);
cards.add(card);
notifyDataSetChanged();
}
#Override
public void remove(CardDataModel card) {
super.remove(card);
cards.remove(card);
notifyDataSetChanged();
}
public class MyViewHolder extends RecyclerView.ViewHolder {
TextView CardNameTxt;
TextView CardDescTxt;
TextView CardPriceTxt;
ImageView favoriteImg;
public MyViewHolder(#NonNull View itemView) {
super(itemView);
this.CardDescTxt = (TextView) itemView.findViewById(R.id.txt_crd_desc);
this.CardNameTxt = (TextView) itemView.findViewById(R.id.txt_crd_name);
this.CardPriceTxt = (TextView) itemView.findViewById(R.id.txt_crd_no);
this.favoriteImg = (ImageView) itemView.findViewById(R.id.imgbtn_favorite);
}}}
The problem part..
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.card_list_item, null);
holder = new ViewHolder();
holder.CardNameTxt = (TextView) convertView
.findViewById(R.id.txt_crd_name);
holder.CardDescTxt = (TextView) convertView
.findViewById(R.id.txt_crd_desc);
holder.CardPriceTxt = (TextView) convertView
.findViewById(R.id.txt_crd_no);
holder.favoriteImg = (ImageView) convertView
.findViewById(R.id.imgbtn_favorite);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
CardDataModel card = (CardDataModel) getItem(position);
holder.CardNameTxt.setText(card.getName());
holder.CardDescTxt.setText(card.getDescription());
holder.CardPriceTxt.setText(card.getPrice() + " ");
/*If a product exists in shared preferences then set heart_red drawable
* and set a tag*/
if (checkFavoriteItem(card)) {
holder.favoriteImg.setImageResource(R.drawable.heart_red);
holder.favoriteImg.setTag("red");
} else {
holder.favoriteImg.setImageResource(R.drawable.heart_grey);
holder.favoriteImg.setTag("grey");
}
return convertView;
}
How to modify this code and where to add this checkFavItem, add , and remove methods..suggest me , i am new to android development.

Finishing RecyclerView Code
// specify the row layout file and click for each row
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(listItemLayout, parent, false);
ViewHolder myViewHolder = new ViewHolder(view);
return myViewHolder;
}
// load data in each row element
#Override
public void onBindViewHolder(final ViewHolder holder, final int listPosition) {
TextView item = holder.item;
item.setText(itemList.get(listPosition).getName());
}

error when running checkbox in listview android

when i was trying tutorial checkbox in listview theres some error on my adapter
public View getView(int position, View convertView, ViewGroup parent) {
ViewTag viewTag;
if (convertView == null) {
//取得listItem容器 view
convertView = myInflater.inflate(R.layout.list_item_pegawai, null);
//建構listItem內容view
viewTag = new ViewTag(
(TextView) convertView.findViewById(R.id.txt_namapegawai),
(CheckBox) convertView.findViewById(R.id.checkBox_pegawai));
//設置容器內容
convertView.setTag(viewTag);
} else {
viewTag = (ViewTag) convertView.getTag();
}

complete code
public class CustomAdapter extends BaseAdapter {
private Context context;
public static ArrayList<Model> modelArrayList;
public CustomAdapter(Context context, ArrayList<Model> modelArrayList) {
this.context = context;
CustomAdapter.modelArrayList = modelArrayList;
}
#Override
public int getViewTypeCount() {
return getCount();
}
#Override
public int getItemViewType(int position) {
return position;
}
#Override
public int getCount() {
return modelArrayList.size();
}
#Override
public Object getItem(int position) {
return modelArrayList.get(position);
}
#Override
public long getItemId(int position) {
return 0;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
if (convertView == null) {
holder = new ViewHolder();
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.list_item_select, null, true);
holder.checkBox = convertView.findViewById(R.id.checkBox);
holder.tvName = convertView.findViewById(R.id.textView7);
holder.Tvnumber = convertView.findViewById(R.id.textView8);
convertView.setTag(holder);
} else {
// the getTag returns the viewHolder object set as a tag to the view
holder = (ViewHolder) convertView.getTag();
}
holder.tvName.setText(modelArrayList.get(position).getName());
holder.Tvnumber.setText(modelArrayList.get(position).getPhone());
holder.checkBox.setChecked(modelArrayList.get(position).getSelected());
holder.checkBox.setTag(R.integer.btnplusview, convertView);
holder.checkBox.setTag(position);
holder.checkBox.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
View tempview = (View) holder.checkBox.getTag(R.integer.btnplusview);
TextView tv = tempview.findViewById(R.id.textView7);
Integer pos = (Integer) holder.checkBox.getTag();
if (modelArrayList.get(pos).getSelected()) {
modelArrayList.get(pos).setSelected(false);
} else {
modelArrayList.get(pos).setSelected(true);
}
}
});
return convertView;
}
private class ViewHolder {
protected CheckBox checkBox;
private TextView tvName;
private TextView Tvnumber;
}
}

listview is not refreshing values after deleting row with checkbox value = true

Good day,
I'm doing a listview, baseadapter with checkbox that is able to delete multiple selected rows.
here is my onCreate :
ArrayList<Memos> list;
list = new ArrayList<Memos>();
list.add(new Memos(1, "s", "s"));
list.add(new Memos(2, "x", "aaa"));
list.add(new Memos(3, "v", "aesf"));
final ListView lv = (ListView) findViewById(R.id.myList);
lv.setAdapter(new MemoListAdapter(list, this));
deletebutton
#Override
public void onClick(View v) {
MemoListAdapter myAdapter = (MemoListAdapter)lv.getAdapter();
myAdapter.remove();
}
then here is my complete baseadapter :
public class MemoListAdapter extends BaseAdapter {
private List<Memos> listComment;
private Context context;
private LayoutInflater inflater = null;
private ArrayList<Memos> deleteMemos;
public MemoListAdapter(List<Memos> listComment, Context context) {
super();
this.listComment = listComment;
this.context = context;
inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
deleteMemos = new ArrayList<Memos>();
}
#Override
public int getCount() {
return listComment.size();
}
#Override
public Memos getItem(int position) {
return listComment.get(position);
}
#Override
public long getItemId(int arg0) {
return 0;
}
#Override
public int getViewTypeCount() {
return getCount();
}
#Override
public int getItemViewType(int position) {
return position;
}
public class ViewHolder
{
TextView body;
TextView date;
CheckBox checkBox;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.list_view, null);
holder = new ViewHolder();
holder.body = (TextView) convertView.findViewById(R.id.big_text);
holder.date = (TextView) convertView.findViewById(R.id.small_text);
holder.checkBox = (CheckBox) convertView.findViewById(R.id.checkbox);
holder.body.setText(listComment.get(position).getMessageBody());
holder.date.setText(listComment.get(position).getMessageDate());
holder.checkBox.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//is chkIos checked?
if(listComment.get(position).isCheckbox()) {
holder.checkBox.setChecked(false);
deleteMemos.remove(listComment.get(position));
}
else {
// Do invisible or gone stuff here
holder.checkBox.setChecked(true);
deleteMemos.add(listComment.get(position));
}
}
});
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
return convertView;
}
public void remove() {
for(Memos memo : deleteMemos) {
listComment.remove(memo);
}
this.notifyDataSetChanged();
}
}
after selecting rows to delete (4 rows)
the list adjusted but the contents and the check value of the checkbox is still the same.
I am wondering what part of the notifyDataSetChanged is wrong.
Thanks in advance!

Your views are reused that's why it happen . Try adding below codes into your getView()
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.list_view, null);
holder = new ViewHolder();
holder.body = (TextView) convertView.findViewById(R.id.big_text);
holder.date = (TextView) convertView.findViewById(R.id.small_text);
holder.checkBox = (CheckBox) convertView.findViewById(R.id.checkbox);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
if(listComment.get(position).isCheckbox()) {
holder.checkBox.setChecked(true);
}else {
holder.checkBox.setChecked(false);
}
holder.body.setText(listComment.get(position).getMessageBody());
holder.date.setText(listComment.get(position).getMessageDate());
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
listComment.get(position).setIsCheckbox(isChecked);
if (isChecked){
deleteMemos.add(listComment.get(position));
}else{
deleteMemos.remove(listComment.get(position));
}
}
});
return convertView;
}

listView checkbox scrolling bug

I have a problem with a listView consisting of check-boxes. When I scroll some items get selected automatically.
This is my code for the getView method in my custom adapter:
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
LayoutInflater inflater = ((Activity)context).getLayoutInflater();
convertView = inflater.inflate(R.layout.prerequisite_course, parent, false);
holder = new ViewHolder();
holder.name = (CheckBox) convertView.findViewById(R.id.course_checkbox);
convertView.setTag(holder);
holder.name.setOnClickListener( new View.OnClickListener() {
public void onClick(View v) {
CheckBox cb = (CheckBox) v ;
Course course = (Course) cb.getTag();
if (cb.isChecked())
checkBoxChecked(cb, course);
else
checkBoxNotChecked(cb, course);
}
});
}
else {
holder = (ViewHolder) convertView.getTag();
}
Course course = coursesDataManager.getCourseInPosition(position);
String currentId = COURSES_SUBJECT + " " + course.getId();
holder.name.setText(currentId);
holder.name.setTag(course);
// for the clear button:
if (!holder.name.isChecked()) {
checkBoxNotChecked(holder.name, (Course) holder.name.getTag());
}
return convertView;
}
private void checkBoxChecked(CheckBox cb, Course add) {
cb.setBackgroundColor(Color.rgb(1, 67, 121));
cb.setTextColor(Color.WHITE);
myCoursesManager.addPrerequisite(add);
}
private void checkBoxNotChecked(CheckBox cb, Course remove) {
cb.setBackgroundColor(Color.WHITE);
cb.setTextColor(Color.BLACK);
myCoursesManager.removePrerequisite(remove);
}
Also, criticism of the code would be welcomed as I'm new to android development. Thank you.

You need to maintain boolean array for checkbox,try this way this worked for me
public class CustomAdapter extends BaseAdapter {
private final LayoutInflater inflater;
private final Context context;
private List<ModelPooja> listData;
public CustomAdapter(Context mainActivity, List<ModelPooja> listData) {
context = mainActivity;
this.listData = listData;
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return listData.size();
}
#Override
public Object getItem(int position) {
return listData.get(position);
}
#Override
public long getItemId(int position) {
return 0;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
if (convertView == null) {
holder = new ViewHolder();
convertView = inflater.inflate(R.layout.list_item_poojaselection, null);
holder.tv = (TextView) convertView.findViewById(R.id.list_item_poojaname);
holder.checks = (CheckBox) convertView.findViewById(R.id.list_item_poojacheck);
convertView.setTag(holder);
}else {
holder = (ViewHolder) convertView.getTag();
}
holder.checks.setOnCheckedChangeListener(null);
holder.checks.setFocusable(false);
if (listData.get(position).isselected) {
holder.checks.setChecked(true);
} else {
holder.checks.setChecked(false);
}
holder.checks.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton cb, boolean b) {
if (checkMaxLimit()) {
if (listData.get(position).isselected && b) {
holder.checks.setChecked(false);
listData.get(position).isselected = false;
} else {
holder.checks.setChecked(false);
listData.get(position).isselected = false;
Toast.makeText(context, "Max limit reached", Toast.LENGTH_SHORT).show();
}
} else {
if (b) {
listData.get(position).isselected = true;
} else {
listData.get(position).isselected = false;
}
}
}
});
holder.tv.setText(listData.get(position).getPOOJA_LISTING_NAME());
return convertView;
}
public boolean checkMaxLimit() {
int countermax = 0;
for(ModelPooja item : listData){
if(item.isselected){
countermax++;
}
}
return countermax >= 5;
}
public class ViewHolder {
TextView tv;
public CheckBox checks;
}
}

Create a Model Class for saving the checkBox status for the list items.
public class ModelClass
{
int position=null;
String item=null;
boolean selected=false;
public ModelClass(int position,String item, boolean selected) {
super();
this.position=position;
this.item=item;
this.selected = selected;
}
}
Then in your Adapter Class
private ArrayList<ModelClass> arl;
Inside your getView()
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
arl.get(position).selected=isChecked;
}
});
holder.checkBox.setChecked(arl.get(position).selected);
And now no matter how much you scroll your checkBoxes state will be consistent(Trust me, I have used this code in my Project).

Optimize listview performance Android

I have a listView (vertical) and every list item has a horizontal list view (horizontal).
But the problem is when i scroll the horizontal scrollview in the row the vertical list is also calling getView()...
So, there is a huge performance hit..
So , can any one tell me a better solution to it ..
public class GridViewAdapter extends BaseAdapter {
List<List<Hotel>> gridDatasource;
Context mContext;
public GridViewAdapter(List<List<Hotel>> gridDatasource, Context context) {
this.gridDatasource = gridDatasource;
this.mContext = context;
}
public void setGridDatasource(List<List<Hotel>> gridDatasource) {
this.gridDatasource = gridDatasource;
}
#Override
public int getCount() {
if (gridDatasource == null) {
return 0;
}
return gridDatasource.size();
}
#Override
public Object getItem(int position) {
return gridDatasource.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
GridViewHolder holder;
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) mContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.gridview_table_cell,
null);
holder = new GridViewHolder();
holder.headerView = (TextView) convertView
.findViewById(R.id.gridViewRowHeader);
holder.listView = (HorizontalListView) convertView
.findViewById(R.id.gridViewHorizontalListView);
convertView.setTag(holder);
} else {
holder = (GridViewHolder) convertView.getTag();
Log.d("TAG", "Reaching Here");
}
holder.headerView.setText("Hello From Sandeep");
HorizontalListViewAdapter adapter = new HorizontalListViewAdapter(
mContext, gridDatasource.get(position));
holder.listView.setAdapter(adapter);
return convertView;
}
}
static class GridViewHolder {
TextView headerView;
HorizontalListView listView;
}
public class HorizontalListViewAdapter extends BaseAdapter {
Context mContext;
List<Hotel> mHotels;
public HorizontalListViewAdapter(Context context, List<Hotel> hotels) {
this.mContext = context;
this.mHotels = hotels;
}
#Override
public int getCount() {
if (mHotels == null) {
return 0;
}
return mHotels.size();
}
#Override
public Object getItem(int position) {
return mHotels.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
HotelCell cell = (HotelCell) convertView;
if (cell == null) {
cell = new HotelCell(mContext);
} else {
Log.d("TAG", "Reached here 2");
}
cell.setHotel(mHotels.get(position));
cell.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(mContext,
HotelDetailActivity.class);
intent.putExtra("DATA", ((HotelCell) v).getHotel());
startActivity(intent);
}
});
cell.setPadding(0, 0, 10, 0);
return cell;
}
}

Dear i suggest to try My this Code
public View getView(final int position, View convertView, ViewGroup parent)
{
View v = convertView;
ViewHolder holder;
if (v == null)
{
v = inflater.inflate(R.layout.custom_image_layout, null);
holder = new ViewHolder();
holder.txtFileName = (TextView) v.findViewById(R.id.txtFileName);
holder.imageView = (ImageView) v.findViewById(R.id.imgView);
v.setTag(holder);
} else
{
holder = (ViewHolder) v.getTag();
}
holder.imageView.setImageBitmap(bm);
holder.txtFileName.setText(""+nameoffile);
return v;
}
static class ViewHolder
{
public ImageView imageView;
public TextView txtFileName;
}
Use The Holder Class