开发笔记:从片段更新ListView适配器内的TextView

我在我的TextView有一个价格OrderFragment，我想更新onItemSelected每个项目的折扣和每个票据Spinner折扣。一旦我改变了我的物品的价格，我尝试在我的notifyDataSetChanged上使用ArrayList，但它没有更新我的ListView。 notifyDataSetChanged工作正常，当我在不同的片段中使用它来添加和删除我的ArrayList元素，但更新价格在ArrayList这似乎不起作用。

为了更新我的每个帐单的折扣，我提到了各种问题，但它似乎没有得到它的工作：notifyDataSetChange not working from custom adapter，Android: notifyDataSetChanged(); not working，Android ListView not refreshing after notifyDataSetChanged和其他人也。然后我尝试使用TextView从我的Fragment更改ListView.getChildAt()但由于ListView仅加载可见行而无法正常工作，因此，其他不可见的行不会更新。

至于每个项目的折扣，我有它的工作，但使用2 Callback似乎效率不高。

OrderFragment

public class OrderFragment extends Fragment {
private ArrayList orderList = new ArrayList();
private ListView lvConfirmOrder;
private ListViewOrderAdapter lvConfirmOrderAdapter;
private TextView tvTotalOrderPrice;
private int totalOrderPrice;
private Spinner sBillDiscount;
private int billDiscount = 0;
private ItemClickListener itemClickListener;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
view = inflater.inflate(R.layout.fragment_order, container, false);
activity = getActivity();
db = DatabaseHelper.getInstance(activity);
Bundle bundle = new Bundle();
orderList = getArguments().getParcelableArrayList("orderList");
tvTotalOrderPrice = (TextView) view.findViewById(R.id.tvShowTotalPrice);
sBillDiscount = (Spinner) view.findViewById(R.id.sBillDiscount);
lvCOnfirmOrder= (ListView) view.findViewById(R.id.lvConfirmOrder);
lvCOnfirmOrderAdapter= new ListViewOrderAdapter(activity, orderList, new ItemClickListener() {
@Override
public void onItemClick(Product product) {
}
@Override
public void onItemClick(ProductCategory productCategory) {
}
@Override
public void onItemClick(ArrayList productList) {
tvTotalOrderPrice.setText(String.format("%d",setTotalPrice()));
}
});
lvConfirmOrder.setAdapter(lvConfirmOrderAdapter);
// Get the total price of all items
totalOrderPrice = setTotalPrice();
// Set the total price into TextView
tvTotalOrderPrice.setText(String.format("%d",totalOrderPrice));
addItemsOnSBillDiscountAndPreselect(billDiscount);
sBillDiscount.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView adapterView, View view, int i, long l) {
float spinnerValue = Float.parseFloat(adapterView.getItemAtPosition(i).toString());
float discount = 1.0f - (spinnerValue/100.0f);
totalAfterDiscount(discount);
}
@Override
public void onNothingSelected(AdapterView adapterView) {
}
});
return view;
}
private int setTotalPrice() {
int totalPrice = 0;
for (int index = 0; index totalPrice += orderList.get(index).getOrderPrice();
}
return totalPrice;
}
// add items into spinner
public void addItemsOnSBillDiscountAndPreselect(int discount) {
List list = new ArrayList();
for(int index = 0; index <= 100; index++) {
list.add(index);
}
ArrayAdapter dataAdapter = new ArrayAdapter(activity,
android.R.layout.simple_spinner_item, list);
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
sBillDiscount.setAdapter(dataAdapter);
int spinnerPosition = dataAdapter.getPosition(discount);
sBillDiscount.setSelection(spinnerPosition);
}
public void totalAfterDiscount(float discount) {
float totalItemPrice[] = new float[orderList.size()];
for (int i = 0; i totalItemPrice[i] = orderList.get(i).getOrderPrice() * discount;
}
TextView tvPrice;
for ( int i = 0 ; i View v = getViewByPosition(i,lvConfirmOrder);
tvPrice = (TextView) v.findViewById(R.id.tvQtyPrice);
tvPrice.setText(String.valueOf(totalItemPrice[i]));
}
tvTotalOrderPrice.setText(String.format("%d",setTotalPrice()));
lvConfirmOrderAdapter.notifyDataSetChanged();
}
public View getViewByPosition(int position, ListView listView) {
final int firstListItemPosition = listView.getFirstVisiblePosition();
final int lastListItemPosition =firstListItemPosition + listView.getChildCount() - 1;
if (position lastListItemPosition ) {
return listView.getAdapter().getView(position, listView.getChildAt(position), listView);
} else {
final int childIndex = position - firstListItemPosition;
return listView.getChildAt(childIndex);
}
}
}


ListViewOrderAdapter

public class ListViewOrderAdapter extends ArrayAdapter {
//to store the list of products
private ArrayList productList = new ArrayList();
private ItemClickListener itemClickListener;
private ViewHolder viewHolder;
private DiscountSpinnerListener discountSpinnerListener;
private static class ViewHolder {
TextView tvProductName;
TextView tvProductSku;
TextView tvPrice;
TextView tvProductNum;
TextView iAddQuantity;
TextView tvQuantity;
TextView tvQtyPrice;
TextView iMinusQuantity;
Spinner sDiscount;
TextView iDelete;
}
public ListViewOrderAdapter(Activity context, ArrayList listProduct, ItemClickListener itemClickListener){
super(context,R.layout.row_order , listProduct);
this.cOntext= context;
this.productList = listProduct;
this.itemClickListener = itemClickListener;
}
public View getView(final int position, View view, ViewGroup parent) {
final Product product = productList.get(position);
if (view == null) {
// If there's no view to re-use, inflate a brand new view for row
viewHolder = new ViewHolder();
LayoutInflater inflater = LayoutInflater.from(context);
view = inflater.inflate(R.layout.row_order, null, false);
viewHolder.tvProductName = (TextView) view.findViewById(R.id.tvOrderProduct);
viewHolder.tvProductSku = (TextView) view.findViewById(R.id.tvOrderSKU);
viewHolder.tvPrice = (TextView) view.findViewById(R.id.tvProductPrice);
viewHolder.tvProductNum = (TextView) view.findViewById(R.id.tvOrderNum);
viewHolder.iAddQuantity = (TextView) view.findViewById(R.id.iAddQuantity);
viewHolder.tvQuantity = (TextView) view.findViewById(R.id.tvQuantity);
viewHolder.tvQtyPrice = (TextView) view.findViewById(R.id.tvQtyPrice);
viewHolder.iMinusQuantity = (TextView) view.findViewById(R.id.iMinusQuantity);
viewHolder.sDiscount = (Spinner) view.findViewById(R.id.sDiscount);
viewHolder.iDelete = (TextView) view.findViewById(R.id.iDelete);
// Cache the viewHolder object inside the fresh view
view.setTag(viewHolder);
} else {
// View is being recycled, retrieve the viewHolder object from tag
viewHolder = (ViewHolder) view.getTag();
}
//this code sets the values of the objects to values from the arrays
viewHolder.tvProductName.setText(product.getProduct_name());
viewHolder.tvProductSku.setText(product.getProduct_sku());
viewHolder.tvPrice.setText(String.valueOf(product.getPrice_max()));
String num = Integer.toString(position + 1);
viewHolder.tvProductNum.setText(num);
viewHolder.tvQuantity.setText(String.valueOf(product.getOrderQuantity()));
addItemsOnSDiscountAndPreselect(viewHolder,product.getDiscount_per_item());
viewHolder.sDiscount.setOnItemSelectedListener(new SpinnerListener(viewHolder, position, new DiscountSpinnerListener() {
@Override
public void onDiscountChange(TextView tvPrice, int pos, float price) {
if (position == pos) {
tvPrice.setText(String.valueOf(price));
itemClickListener.onItemClick(productList);
}
}
}));
fOnt= Typeface.createFromAsset(context.getAssets(), "fonts/fontawesome-webfont.ttf" );
viewHolder.iAddQuantity.setTypeface(font);
viewHolder.iMinusQuantity.setTypeface(font);
viewHolder.iDelete.setTypeface(font);
viewHolder.iAddQuantity.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
product.setOrderQuantity(product.getOrderQuantity() + 1);
product.setOrderPrice(product.getOrderQuantity() * product.getPrice_max());
itemClickListener.onItemClick(productList);
notifyDataSetChanged();
}
});
viewHolder.iMinusQuantity.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
product.setOrderQuantity(product.getOrderQuantity() - 1);
product.setOrderPrice(product.getOrderQuantity() * product.getPrice_max());
if (product.getOrderQuantity() == 0) {
createAndShowAlertDialog(position, productList);
} else {
itemClickListener.onItemClick(productList);
notifyDataSetChanged();
}
}
});
viewHolder.iDelete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
createAndShowAlertDialog(position, productList);
notifyDataSetChanged();
}
});
return view;
}
private void createAndShowAlertDialog(final int position, final ArrayList productList) {
AlertDialog.Builder builder = new AlertDialog.Builder(context,R.style.MyDialogTheme);
builder.setTitle("Are you sure you want to delete " + productList.get(position).getProduct_name());
builder.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
productList.remove(position);
itemClickListener.onItemClick(productList);
notifyDataSetChanged();
dialog.dismiss();
}
});
builder.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
productList.get(position).setOrderQuantity(1);
dialog.dismiss();
}
});
AlertDialog dialog = builder.create();
dialog.setCancelable(false);
dialog.setCanceledOnTouchOutside(false);
dialog.show();
}
// add items into spinner
public void addItemsOnSDiscountAndPreselect(ViewHolder viewHolder, int discount) {
List list = new ArrayList();
for(int index = 0; index <= 100; index++) {
list.add(index);
}
ArrayAdapter dataAdapter = new ArrayAdapter(context,
android.R.layout.simple_spinner_item, list);
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
viewHolder.sDiscount.setAdapter(dataAdapter);
int spinnerPosition = dataAdapter.getPosition(discount);
viewHolder.sDiscount.setSelection(spinnerPosition);
}
private class SpinnerListener implements AdapterView.OnItemSelectedListener {
private int mSpinnerPosition;
private DiscountSpinnerListener discountSpinnerListener;
private ViewHolder viewHolder;
public SpinnerListener(ViewHolder viewHolder, int spinnerPosition, DiscountSpinnerListener discountSpinnerListener) {
mSpinnerPosition = spinnerPosition;
this.discountSpinnerListener = discountSpinnerListener;
this.viewHolder = viewHolder;
}
@Override
public void onItemSelected(AdapterView arg0, View arg1, int arg2, long arg3) {
float spinnerValue = Float.parseFloat(arg0.getItemAtPosition(arg2).toString());
float discount = 1.0f - (spinnerValue/100.0f);
float totalItemPrice = productList.get(mSpinnerPosition).getPrice_max() * productList.get(mSpinnerPosition).getOrderQuantity() * discount;
productList.get(mSpinnerPosition).setOrderPrice(totalItemPrice);
productList.get(mSpinnerPosition).setDiscount_per_item(Integer.parseInt(arg0.getItemAtPosition(arg2).toString()));
// Listener to set total price of an item after discount
discountSpinnerListener.onDiscountChange(viewHolder.tvQtyPrice, mSpinnerPosition, totalItemPrice);
}
@Override
public void onNothingSelected(AdapterView arg0) {
// TODO Auto-generated method stub
}
}
}


P / S：请先忽略计算以获得折扣价，因为它确实与我的两个折扣微调器冲突（最初我只实现了每件商品的折扣）。

这是我的应用程序的屏幕截图：See here