using notifyItemRemoved or notifyDataSetChanged with RecyclerView in Android
I am creating a list of cards to display using the RecyclerView, where each card has a button to remove that card from the list.
When i use notifyItemRemoved() to remove the card in the RecyclerView, it removes the item and animates fine but the data in the list is not updated correctly.
If instead of that, i switch to the notifyDataSetChanged() then the items in list are removed and updated correctly, but then the cards dont animate.
Does someone has any experience in using the notifyItemRemoved() and know why it behaves differently than notifyDataSetChanged?
Here is some peiece of code that i am using:
private List<DetectedIssue> issues = new ArrayList<DetectedIssue>();
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
if(position >0){
RiskViewHolder riskHolder = (RiskViewHolder)holder;
final int index = position - 1;
final DetectedIssue anIssue = issues.get(index);
riskHolder.button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
int index = issues.indexOf(anIssue);
issues.remove(anIssue);
notifyItemRemoved(index);
//notifyDataSetChanged();
} catch (SQLException e) {
e.printStackTrace();
}
}
});
}
}
@Override
public int getItemCount() {
return (issues.size()+1);
}
Use notifyItemRangeChanged(position, getItemCount()); after notifyItemRemoved(position);
You don't need to use index, just use position. See code below.
private List<DetectedIssue> issues = new ArrayList<DetectedIssue>();
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
if(position >0){
RiskViewHolder riskHolder = (RiskViewHolder)holder;
riskHolder.button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
try {
issues.remove(position);
notifyItemRemoved(position);
//this line below gives you the animation and also updates the
//list items after the deleted item
notifyItemRangeChanged(position, getItemCount());
} catch (SQLException e) {
e.printStackTrace();
}
}
});
}
}
@Override
public int getItemCount() {
return issues.size();
}
Tried
public void removeItem(int position) {
this.taskLists.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, getItemCount() - position);
}
and working like a charm.
my mistake , notifyItemChanged(position) is helpless,the item of position can be removed ,and the item of position+1 is fine,but the items start from position+2,you will get an Exception, please use notifyItemRangeChanged(position,getItemCount()); after notifyItemRemoved(position);
like this:
public void removeData(int position) {
yourdatalist.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position,getItemCount());
}