在listview中，我有一个增量和减量按钮，用于更改数量。增加和减少的操作工作正常。但数量将在其他活动中显示在数组中。请帮助我，我是Android开发的新手。 first activity和second activity点按
public class CatalogActivity extends Activity implements CustomButtonListener{
private List<Product> mProductList;
static int quantity2;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.catalog);
// Obtain a reference to the product catalog
mProductList = ShoppingCartHelper.getCatalog(getResources());
// Make sure to clear the selections
for(int i=0; i<mProductList.size(); i++) {
mProductList.get(i).selected = false;
}
// Create the list
ListView listViewCatalog = (ListView) findViewById(R.id.ListViewCatalog);
listViewCatalog.setAdapter(new ProductAdapter(mProductList, getLayoutInflater(), false));
Button viewShoppingCart = (Button) findViewById(R.id.ButtonViewCart);
ProductAdapter.setCustomButtonListener(this);
viewShoppingCart.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent viewShoppingCartIntent = new Intent(getBaseContext(), ShoppingCartActivity.class);
startActivity(viewShoppingCartIntent);
}
});
}
@Override
public void onButtonClickListener(int position, TextView editText, int value) {
quantity2 = Integer.parseInt(editText.getText().toString());
quantity2 = quantity2+1*value;
if(quantity2<0)
quantity2=0;
editText.setText(quantity2+"");
}
}
public class ProductAdapter extends BaseAdapter {
private List<Product> mProductList;
private LayoutInflater mInflater;
private boolean mShowQuantity;
public static int quantity = 0;
public Context context;
public static ArrayList<Integer> quantity1 = new ArrayList<Integer>();
static CustomButtonListener customButtonListener;
public static int quant;
public ProductAdapter(List<Product> list, LayoutInflater inflater, boolean showQuantity) {
mProductList = list;
mInflater = inflater;
mShowQuantity = showQuantity;
for (int i = 0; i < list.size(); i++) {
quantity1.add(0);
}
}
public static void setCustomButtonListener(CustomButtonListener customButtonListner) {
customButtonListener = customButtonListner;
}
@Override
public int getCount() {
return mProductList.size();
}
@Override
public Product getItem(int position) {
return mProductList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewItem item;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.item, null);
item = new ViewItem();
item.productImageView = (ImageView) convertView
.findViewById(R.id.ImageViewItem);
item.productTitle = (TextView) convertView
.findViewById(R.id.TextViewItem);
item.productQuantity = (TextView) convertView
.findViewById(R.id.textViewQuantity);
item.productCost = (TextView) convertView
.findViewById(R.id.itemcost);
item.productbtn = (Button) convertView.findViewById(R.id.btn_plus);
item.textquanty = (TextView) convertView.findViewById(R.id.num);
item.productbtnminus = (Button) convertView.findViewById(R.id.btn_minus);
item.Layout = (View) convertView.findViewById(R.id.add);
getItem(position).setSelected(false);
convertView.setTag(item);
} else {
item = (ViewItem) convertView.getTag();
}
final Product product = getItem(position);
try {
item.textquanty.setText(quantity1.get(position) + "");
} catch (Exception e) {
e.printStackTrace();
}
item.productbtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
if (customButtonListener != null) {
customButtonListener.onButtonClickListener(position, item.textquanty, 1);
quantity1.set(position, quantity1.get(position) + 1);
ShoppingCartHelper.setQuantity(curProduct, quantity1, position);
}
}
});
item.productbtnminus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
if (customButtonListener != null) {
customButtonListener.onButtonClickListener(position, item.textquanty, -1);
if (quantity1.get(position) > 0)
quantity1.set(position, quantity1.get(position) - 1);
ShoppingCartHelper.setQuantity(curProduct, quantity1, position);
}
}
});
item.productImageView.setImageDrawable(product.productImage);
item.productTitle.setText(product.title);
item.productCost.setText("" + product.price);
if (mShowQuantity) {
item.productQuantity.setText("Quantity: " + ShoppingCartHelper.getProductQuantity(product, position));
item.Layout.setVisibility(View.GONE);
} else {
item.productQuantity.setVisibility(View.GONE);
}
return convertView;
}
public static Integer getProductQuantity(Product product, int position) {
ShoppingCartEntry curEntry = ShoppingCartHelper.cartMap.get(product);
if (curEntry != null)
quant=Integer.parseInt((quantity1.get(position)+""));
return quant;
}
private class ViewItem {
ImageView productImageView;
TextView productTitle;
TextView productQuantity;
TextView productCost;
public Button productbtn;
public Button productbtnminus;
View Layout;
public TextView textquanty;
}
}
public class Product {
public String title;
public Drawable productImage;
public String description;
public double price;
private int quantity;
public int getQuantity() {
return quantity;
}
public void setQuantity(int quantity) {
this.quantity = quantity;
}
public Product(String title, Drawable productImage, String description,
double price) {
this.title = title;
this.productImage = productImage;
this.description = description;
this.price = price;
}
}
public class ShoppingCartEntry {
private Product mProduct;
private ArrayList<Integer> mQuantity;
public ShoppingCartEntry(Product product, ArrayList<Integer> quantity1) {
mProduct = product;
mQuantity = quantity1;
}
public Product getProduct() {
return mProduct;
}
public ArrayList<Integer> getQuantity(int position) {
return mQuantity;
}
public void setQuantity(ArrayList<Integer> quantity1) {
mQuantity = quantity1;
}
}
public class ShoppingCartHelper {
public static final String PRODUCT_INDEX = "PRODUCT_INDEX";
protected static List<Product> catalog;
public static Map<Product, ShoppingCartEntry> cartMap = new HashMap<Product, ShoppingCartEntry>();
public static List<Product> getCatalog(Resources res){
if(catalog == null) {
catalog = new Vector<Product>();
catalog.add(new Product("Chiken Curry", res .getDrawable(R.drawable.deadoralive),"Dead or Alive by Tom Clancy with Grant Blackwood", 29.99));
catalog.add(new Product("Mutton Curry", res .getDrawable(R.drawable.switchbook), "Switch by Chip Heath and Dan Heath", 24.99));
catalog.add(new Product("Aloo Curry", res.getDrawable(R.drawable.watchmen), "Watchmen by Alan Moore and Dave Gibbons", 14.99));
catalog.add(new Product("ChikenBiryani", res .getDrawable(R.drawable.deadoralive),"Dead or Alive by Tom Clancy with Grant Blackwood", 25.99));
catalog.add(new Product("MuttonBiryani", res .getDrawable(R.drawable.switchbook), "Switch by Chip Heath and Dan Heath", 21.99));
catalog.add(new Product("Aloo Curry", res.getDrawable(R.drawable.watchmen), "Watchmen by Alan Moore and Dave Gibbons", 12.99));
catalog.add(new Product("Chiken Curry", res .getDrawable(R.drawable.deadoralive),"Dead or Alive by Tom Clancy with Grant Blackwood", 30.99));
catalog.add(new Product("Mutton Curry", res .getDrawable(R.drawable.switchbook), "Switch by Chip Heath and Dan Heath", 28.99));
catalog.add(new Product("Aloo Curry", res.getDrawable(R.drawable.watchmen), "Watchmen by Alan Moore and Dave Gibbons", 18.99));
}
return catalog;
}
public static void setQuantity(Product product, ArrayList<Integer> quantity1, int position) {
// Get the current cart entry
ShoppingCartEntry curEntry = cartMap.get(product);
// If the quantity is zero or less, remove the products
if(ProductAdapter.quantity1.get(position) <= 0) {
if(curEntry != null)
removeProduct(product);
return;
}
// If a current cart entry doesn't exist, create one
if(curEntry == null) {
curEntry = new ShoppingCartEntry(product, quantity1);
cartMap.put(product, curEntry);
return;
}
// Update the quantity
curEntry.setQuantity(quantity1);
}
public static ArrayList<Integer> getProductQuantity(Product product, int position) {
// Get the current cart entry
ShoppingCartEntry curEntry = cartMap.get(product);
if(curEntry != null)
return curEntry.getQuantity(position);
return null;
}
public static void removeProduct(Product product) {
cartMap.remove(product);
}
public static List<Product> getCartList() {
List<Product> cartList = new Vector<Product>(cartMap.keySet().size());
for(Product p : cartMap.keySet()) {
cartList.add(p);
}
return cartList;
}
}