Question

我为购物应用程序创建了购物车组件，但遇到一个问题，当我更新产品数量时，它会更新总价，而不是商品价格（末尾为图片），我的代码在下面

reducer.js

if (action.type === ADD_TO_CART) {
    let addedItem = state.jeans.find((item) => item.id === action.id);
    let existed_item = state.addedItems.find((item) => action.id === item.id);
    if (existed_item) {
      addedItem.quantity += 1;
      return {
        ...state.jeans,
        total: state.total + addedItem.price,
      };
    } else {
      addedItem.quantity = 1;
      let newTotal = state.total + addedItem.price;

      return {
        ...state,
        addedItems: [...state.addedItems, addedItem],
        total: newTotal,
      };
    }
  }
  //INSIDE CART COMPONENT
  if (action.type === ADD_QUANTITY) {
    let addedItem = state.jeans.find((item) => item.id === action.id);
    addedItem.quantity += 1;
    let newTotal = state.total + addedItem.price;
    return {
      ...state,
      total: newTotal,
    };
  }
  if (action.type === SUB_QUANTITY) {
    let addedItem = state.jeans.find((item) => item.id === action.id);
    //if the qt == 0 then it should be removed
    if (addedItem.quantity === 1) {
      let new_items = state.addedItems.filter((item) => item.id !== action.id);
      let newTotal = state.total - addedItem.price;
      return {
        ...state,
        addedItems: new_items,
        total: newTotal,
      };
    } else {
      addedItem.quantity -= 1;
      let newTotal = state.total - addedItem.price;
      return {
        ...state,
        total: newTotal,
      };
    }

这就是我的减速器，我在其中添加了更新数量的功能

cart.js

Footer = () => {
    return (
      <View style={styles.totalContainer}>
        <Text style={styles.textTotal}>Total:</Text>
        <Text style={styles.total}>Rs {this.props.total}</Text>
      </View>
    );
  };

  render() {
    let addedItems =
      this.props.items && this.props.items.length ? (
        <FlatList
          data={this.props.items}
          key={(items) => items.id.toString()}
          numColumns={2}
          ListFooterComponent={this.Footer}
          renderItem={({ item }) => (
            <View style={styles.cartContainer}>
              <TouchableOpacity style={styles.button}>
                <MaterialCommunityIcons
                  name="delete-circle-outline"
                  size={28}
                  onPress={() => this.props.removeItem(item.id)}
                />
              </TouchableOpacity>
              <Image style={styles.image} source={item.image} />
              <View style={{ width: 150 }}>
                <Text style={styles.title}>{item.title}</Text>
                <Text style={styles.subTitle} numberOfLines={1}>
                  {item.subTitle}
                </Text>
              </View>
              <Text style={styles.quantity} numberOfLines={2}>
                {item.quantity}
              </Text>
              <Text style={styles.price}>Rs {item.price}</Text>
              <TouchableWithoutFeedback>
                <MaterialCommunityIcons
                  style={styles.iconUp}
                  size={20}
                  name="plus-circle-outline"
                  onPress={() => this.props.addQuantity(item.id)}
                />
              </TouchableWithoutFeedback>
              <MaterialCommunityIcons
                style={styles.iconDown}
                size={20}
                name="minus-circle-outline"
                onPress={() => this.props.subtractQuantity(item.id)}
              />
            </View>
          )}
        />
      ) : (
        <View style={styles.emptyContainer}>
          <Text style={styles.empty}>There is Nothing in your Cart</Text>
        </View>
      );

    return (
      <View style={styles.container}>
        <View style={styles.order}>
          <Text style={styles.orderText}>You Orders:</Text>
        </View>
        <View>{addedItems}</View>
      </View>
    );
  }
}

const mapStateToProps = (state) => {
  return {
    items: state.clothes.addedItems,
    total: state.clothes.total,
  };
};

const mapDispatchToProps = (dispatch) => {
  return {
    removeItem: (id) => dispatch(removeItem(id)),
    addQuantity: (id) => dispatch(addQuantity(id)),
    subtractQuantity: (id) => dispatch(subtractQuantity(id)),
  };
};

这是我的购物车代码，在这里我面临另一个问题，即我的页脚功能正在显示，如果我添加更多产品，则平面列表无法正常工作。平面列表仅显示3个产品，其他产品将添加在它们的上方。

有人可以帮助我，告诉我怎么回事吗？

Answer 1

您没有在任何地方更新价格

您可以像下面这样

<Text style={styles.price}>Rs {item.price*item.quantity}</Text>

或者，如果您希望这些值处于redux状态，请考虑在化简器级别上更新该值。

React Native，购物车项目值未更新

1 个答案: