React Native，购物车项目值未更新

Question

我为我的购物应用程序创建了一个购物车组件，但我面临一个问题，当我更新产品数量时，它会更新总价而不是商品价格（最后是图片），我的代码如下

减速器.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,
      };
    }

那是我的减速器，我在其中添加了更新数量的功能，

购物车.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，这里我面临另一个问题，如果我添加更多产品，我的页脚功能正在显示并且平面列表无法正常工作平面列表将仅显示 3 个产品，我们将在它们上方添加其他产品。

有人请帮助我并告诉我发生了什么事吗？

Answer 1

您没有在任何地方更新价格

你可以像下面这样

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

或者，如果您希望值处于 redux 状态，请考虑更新 reducer 级别中的值。