无法获取所选项目_id

Question

我无法从列表视图中重新获取所选项目的ID。 我在做什么的逻辑是：我有一个产品显示在列表视图。当我点击编辑本产品时，它会将我发送到产品的详细信息页面。这里的产品名称，价格等都是可以接受的，除了ID以外。 谁能告诉我我做错了什么？下面是代码： 类数据库处理器

//addItemToDB 
public void addItem(ItemModel item) { 
    SQLiteDatabase db = this.getWritableDatabase(); 

    ContentValues values = new ContentValues(); 
    values.put(Constants.PRODUCT_ID, item.getItemId()); 
    values.put(Constants.PRODUCT_NAME, item.getItemName()); 
    values.put(Constants.PRODUCT_PRICE, item.getItemPrice()); 
    db.insert(Constants.TABLE_NAME, null, values); 
} 

> //get all items 
public ArrayList<ItemModel> getAllItems() { 

    SQLiteDatabase db = getReadableDatabase(); 

    Cursor cursor = db.query(Constants.TABLE_NAME, new String[]{Constants.PRODUCT_ID, Constants.PRODUCT_NAME, Constants.PRODUCT_PRICE}, 
      null, null, null, null, Constants.PRODUCT_DATE + " DESC"); 

    if (cursor.moveToFirst()) { 
     do { 

      ItemModel model = new ItemModel(); 

      //format date 
      java.text.DateFormat dateFormat = java.text.DateFormat.getDateInstance(); 
      String data = dateFormat.format(new Date(cursor.getLong(cursor.getColumnIndex(Constants.PRODUCT_DATE)))); 

      model.setItemId(cursor.getInt(cursor.getColumnIndex(Constants.PRODUCT_ID))); 
      model.setItemName(cursor.getString(cursor.getColumnIndex(Constants.PRODUCT_NAME))); 
      model.setItemPrice(cursor.getDouble(cursor.getColumnIndexOrThrow(Constants.PRODUCT_PRICE))); 

      modelArrayList.add(model); 

     } while (cursor.moveToNext()); 
    } 
    return modelArrayList; 

在listViewAdapter我有getView方法：

@Override 
public View getView(final int position, View convertView, ViewGroup parent) { 

    View row = convertView; 
    final ViewHolder holder; 

    if (row == null || (row.getTag()) == null){ 

     LayoutInflater inflater = LayoutInflater.from(activity); 
     row = inflater.inflate(layoutResource,null); 

     holder = new ViewHolder(); 

     holder.hItemName = (TextView) row.findViewById(R.id.custom_row_productName); 
     holder.hItemPrice = (TextView) row.findViewById(R.id.custom_row_productPrice); 

     holder.hItemEdit = (ImageView) row.findViewById(R.id.custom_row_edit); 

     row.setTag(holder); 
    } else { 
     holder = (ViewHolder) row.getTag(); 
    } 

    holder.hModel = getItem(position); 

    holder.hItemName.setText(holder.hModel.getItemName()); 
    holder.hItemPrice.setText(String.valueOf(holder.hModel.getItemPrice())); 

    holder.hItemEdit.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      int itemID = holder.hModel.getItemId(); 
      String itemName = holder.hModel.getItemName(); 
      String itemPrice = String.valueOf(holder.hModel.getItemPrice()); 

      Intent intent = new Intent(activity, ItemDetail.class); 

      intent.putExtra("id", itemID); 
      intent.putExtra("product", itemName); 
      intent.putExtra("price", itemPrice); 
      intent.putExtra("type", itemType); 

      startActivity(activity, intent,null); 
     } 
    }); 

并在该产品的详细信息页面onCreate我有：

Bundle extras = getIntent().getExtras(); 
if (extras != null) { 
      itemProductName.setText(extras.getString("product")); 
      itemPrice.setText(extras.getString("price")); 
      final int itemID = extras.getInt("id"); 

      saveButton.setOnClickListener(new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
         dbHandler.updateItem(itemID); 
         Toast.makeText(ItemDetail.this, itemProductName.getText().toString() + " was modified", Toast.LENGTH_SHORT).show(); 

         startActivity(new Intent(ItemDetail.this, MainActivity.class)); 
        } 
       } 
      }); 
    } 

Answer 1

我发现这个问题，就在您的适配器仅更换一个行：

从

intent.putExtra("id", itemID); 

到

intent.putExtra("id", ""+itemID); 

还有一个编辑，你哈瓦做：

Bundle extras = getIntent().getExtras(); 
if (extras != null) { 
      itemProductName.setText(extras.getString("product")); 
      itemPrice.setText(extras.getString("price")); 

//Here is the one change 

      final String itemID = extras.getString("id"); 

      saveButton.setOnClickListener(new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
         dbHandler.updateItem(itemID); 
         Toast.makeText(ItemDetail.this, itemProductName.getText().toString() + " was modified", Toast.LENGTH_SHORT).show(); 

         startActivity(new Intent(ItemDetail.this, MainActivity.class)); 
        } 
       } 
      }); 
    }