问题
I am trying to develop e-commerce type of app in which user can add item to cart. But I am unable to update the cart badge counter from adapter. Here is screenshot of my app.
I am using Recycler view inside fragment. And I am referring this below link for menu item count.
https://mobikul.com/adding-badge-count-on-menu-items-like-cart-notification-etc/
My problem is I cannot access menu item from adapter.
Here is my fragment code.
PriceListFragment.java
public class PriceListFragment extends Fragment {
public ArrayList<Design> designList;
private Single_DesignAdapter adapter;
private RecyclerView recyclerView;
public PriceListFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, final ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
setHasOptionsMenu(true);
View v = inflater.inflate(R.layout.fragment_price_list, container, false);
recyclerView = (RecyclerView)v.findViewById(R.id.pl_recycler_view);
designList = new ArrayList<Design>();
designList = list();
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
recyclerView.setHasFixedSize(true);
adapter = new Single_DesignAdapter(getContext(), designList);
recyclerView.setAdapter(adapter);
return v;
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.cart_menu, menu);
super.onCreateOptionsMenu(menu, inflater);
MenuItem itemCart = menu.findItem(R.id.menu_cart);
LayerDrawable icon = (LayerDrawable) itemCart.getIcon();
setBadgeCount(getContext(), icon, 0);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_cart:
Toast.makeText(getActivity(), "cart", Toast.LENGTH_SHORT). show();
return false;
default:
break;
}
return false;
}
public ArrayList<Design> list() {
ArrayList<Design> arrayList = new ArrayList<Design>();
Design design = new Design();
design.name = "Black";
design.image = "http://website/Demo/images/1.jpg";
design.designName = "11001";
design.qualityName = "Cotton";
design.amount = "1000";
design.discPercent = "5";
Design design2 = new Design();
design2.name = "Green";
design2.image = "http://website/Demo/images/2.jpg";
design2.designName = "11001";
design2.qualityName = "Cotton";
design2.amount = "900";
design2.discPercent = "9";
arrayList.add(design);
arrayList.add(design2);
return arrayList;
}
public static void setBadgeCount(Context context, LayerDrawable icon, int count) {
BadgeDrawable badge;
// Reuse drawable if possible
Drawable reuse = icon.findDrawableByLayerId(R.id.ic_badge);
if (reuse != null && reuse instanceof BadgeDrawable) {
badge = (BadgeDrawable) reuse;
} else {
badge = new BadgeDrawable(context);
}
badge.setCount(count);
icon.mutate();
icon.setDrawableByLayerId(R.id.ic_badge, badge);
}
}
Design is my model class
Design.java
public class Design implements Serializable{
public String id;
public String qualityId;
public String qualityName;
public String designId;
public String designName;
public String image;
public String name; //use as shade name
public String discPercent;
public String amount;
public String pcs;
public String qty;
}
Single_DesignAdapter.java
public class Single_DesignAdapter extends RecyclerView.Adapter<Single_DesignAdapter.ViewHolder> {
public ArrayList<Design> designList;
private Context context;
private LayoutInflater layoutInflater;
public Single_DesignAdapter(Context context, ArrayList<Design> designList) {
this.designList = designList;
this.context = context;
this.layoutInflater = LayoutInflater.from(context);
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = layoutInflater.inflate(R.layout.single_design, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(final ViewHolder holder, int position) {
Design design = designList.get(position);
holder.tvQuality.setText(design.qualityName);
holder.tvDesign.setText(design.designName);
holder.tvShade.setText(design.name);
if (!design.discPercent.equals("0")) {
holder.tvDisPer.setText("-"+design.discPercent+"%");
holder.tvAmount.setPaintFlags(holder.tvAmount.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
int a = Integer.parseInt(design.amount);
float b = Float.parseFloat(design.discPercent) / 100;
holder.tvAmount.setText("₹ " + design.amount);
int c = (int) (a * b);
int d = a-c;
holder.tvDiscAmt.setText("₹ " +d);
Picasso.with(context).load(design.image).into(holder.ivDesign);
} else {
holder.tvAmount.setText("₹ " + design.amount);
Picasso.with(context).load(design.image).into(holder.ivDesign);
holder.tvDisPer.setVisibility(View.INVISIBLE);
holder.tvDiscAmt.setVisibility(View.INVISIBLE);
}
holder.btAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
holder.llAdd.setVisibility(View.GONE);
holder.llPlusMinus.setVisibility(View.VISIBLE);
}
});
holder.btPlus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (Integer.parseInt(holder.btPcsCount.getText().toString()) >= 1) {
int a = Integer.parseInt(holder.btPcsCount.getText().toString());
int x = a++;
holder.btPcsCount.setText(Integer.toString(a));
}
}
});
holder.btMinus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (Integer.parseInt(holder.btPcsCount.getText().toString()) <= 1) {
holder.llAdd.setVisibility(View.VISIBLE);
holder.llPlusMinus.setVisibility(View.GONE);
} else {
int a = Integer.parseInt(holder.btPcsCount.getText().toString());
a--;
holder.btPcsCount.setText(Integer.toString(a));
}
}
});
}
@Override
public int getItemCount() {
return designList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
public LinearLayout llPer, llAdd, llPlusMinus;
public Button btPlus, btMinus, btPcsCount, btAdd;
public ImageView ivDesign;
public TextView tvDesign, tvQuality, tvShade, tvAmount, tvDiscAmt, tvDisPer;
public ViewHolder(View itemView) {
super(itemView);
btPlus = (Button) itemView.findViewById(R.id.btPlus);
//other find view by ids
}
}
}
Now when user add item to cart it should increment counter. I will add every cart items in ArrayList<Design> and then I will save this list into shared preference. I will manage everything, but I am unable understand that How can I update counter of cart from adapter. I cannot access menu in adapter. If there is other way to do this, Please help.
回答1:
Since you already have a Context in your Adapter. You can cast that to Activity. This way you have access to the menu.
//when item is added or removed
((Activity)this.context).invalidateOptionsMenu()
In your Fragment.onCreateOptionsMenu you can go ahead and set the item count
回答2:
In your fragment click event:
((MainActivity) getActivity()).createCartBadge("value");
Your activity contains this method:
public void createCartBadge(int i) {
MenuItem cartItem = mToolbarMenu.findItem(R.id.cart);
LayerDrawable localLayerDrawable = (LayerDrawable) cartItem.getIcon();
Drawable cartBadgeDrawable = localLayerDrawable
.findDrawableByLayerId(R.id.ic_badge);
BadgeDrawable badgeDrawable;
if ((cartBadgeDrawable != null)
&& ((cartBadgeDrawable instanceof BadgeDrawable))
&& (i < 10)) {
badgeDrawable = (BadgeDrawable) cartBadgeDrawable;
} else {
badgeDrawable = new BadgeDrawable(MainActivity.this);
}
badgeDrawable.setCount(i);
localLayerDrawable.mutate();
localLayerDrawable.setDrawableByLayerId(R.id.ic_badge, badgeDrawable);
cartItem.setIcon(localLayerDrawable);
}
回答3:
You can use Interface to communicate between the Fragment and the Adapter.
for example:
public interface CallbackInterface {
void onCall();
}
and in your PriceListFragment in onCreateView do that:
CallbackInterface callback = new CallbackInterface{
@Override
public void onCall() {
if(itemCart!=null){
//code to increment badge
}
}
};
and pass callback to the adapter's constructor and then use it there.
回答4:
You can use badge style in TextView now, All you need to do is adjust your textview position to make it look like badge.
<TextView
android:id="@+id/fabCounter"
style="@style/Widget.Design.FloatingActionButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_centerVertical="true"
android:layout_marginEnd="10dp"
android:padding="5dp"
android:text="-9"
android:textColor="@android:color/black"
android:textSize="14sp" />
来源：https://stackoverflow.com/questions/43015908/android-change-cart-menu-badge-counter-from-recycler-adapter