Sergey Chyzhyk's questions

所以我有一个具有以下架构的数据库：

namespace eShop.Entities
{
public class ListCities
{
    public string Id { get; set; }
    public string ParentId { get; set; }
    public string Name { get; set; }

    public ICollection<CityArea> CityAreas { get; set; } = new List<CityArea>();
}

public class CityArea
{
    public string Id { get; set; }
    public string ParentId { get; set; }
    public string Name { get; set; }

    public ICollection<City> Cities { get; set; } = new List<City>();
}

public class City
{
    public string Id { get; set; }
    public string ParentId { get; set; }
    public string Name { get; set; }
    public ICollection<AppUser> AppUsers = new List<AppUser>();
}

}

一个 json 格式的对象从前面出现，我将其转换为 ListCities 对象。这是一个例子

[HttpPost]
    public async void Post(string jsonData)
    {
        ListCities list = JsonConvert.DeserializeObject<ListCities>(jsonData);
        await _cityRepository.SaveCitiesAsync(list);
    }

如何正确实现 SaveCitiesAsync() 方法，以便该对象立即输入数据库，考虑到所有链接，并分布在必要的表中？

public async Task SaveCitiesAsync(ListCities listCities)
    {
        ListCities newListCities = new ListCities {
           //как писать код тут?
        };
        await Context.ListCities.AddAsync(newListCities);
        await Context.SaveChangesAsync();
    }

docker cp ./Views/Home/Index.cshtml exampleApp3000:/app/Views/Home/

该命令在命令行上告诉我这样的目录不存在。问题。如何查看容器内的可用目录列表？我怎样才能知道我可以将它移动到哪里？

在一个普通的静态页面上，我使用了 3 个不同的反应组件

函数渲染应用程序（）{

ReactDOM.render(
    <ShopList />,   
    document.getElementById("shop-list")
);

ReactDOM.render(
    <Filter />,
    document.getElementById("shop-filter")
);

ReactDOM.render(
    <Pagination />,
    document.getElementById("pagination-area")
);

}

含义如下：组件向服务器发起ajax请求，并将Category作为参数传递。我需要从 URL 中获取类别。怎么做？

URL: /Shop/Category?category=Cameras%20%26%20摄影

初始文件

import React, { Component } from "react";
import {connect} from "react-redux";
import List from "../../components/List";
import { getData } from "../../store/actions/getData";
import Spinner from "../../UI/Spinner/Spinner";

class ProductsArea extends Component {

    componentDidMount() {
        this.props.onGetProducts();
    }

    render() {
        if (this.props.products.length === 0) {
            return <Spinner />;
        }
        return <List isProducts = {this.props.products}/>;
    }
}

const mapStateToProps = (state) => {
    return  {
        products: state.prod
    }
};

const dispatchStateToProps = (dispatch) => {
    return  {
        onGetProducts: () => getData(dispatch)
    }
};

export default connect(mapStateToProps, dispatchStateToProps)(ProductsArea);


//метод getData

export function getData(dispatch) {
    dispatch({ type: actions.PRODUCTS_LOADING});
    axios.get("api/getData")
        .then(res => {
            dispatch({
                type: actions.GET_PROD_LIST,
                val: res.data
            });
        });
}

//List - 这里Render方法被执行了无数次，成功接收到数据

import React, {Component} from "react";
import Spinner from "../UI/Spinner/Spinner";

class List extends Component {

    state = {
        dataLoaded: false
    };

    dataLoadHandler = () => {
        this.setState({ dataLoaded: true });
    };


    render() {

        let result = <Spinner/>;
        const products = this.props.isProducts;

        console.log(products);

        if (products.length > 0) {
            this.dataLoadHandler();
        } 

        if (this.state.dataLoaded) {
            result = products.map(prod => {

                const primaryImgUrl = `img/product/mediam/${prod.PrimaryImg}`;
                const secondaryImgUrl = `img/product/mediam/${prod.SecondaryImg}`;

                const isNew = prod.New ? 
                (<div className="label_new">
                        <span className="new">new</span>
                    </div>) : null;

                const isSalePercent = prod.SalePercent != null ? 
                (<div className="sale-off">
                        <span className="sale-percent">-55%</span>
                    </div>) : null;

                return (<div className="single-product">
                    <div className="col-md-3 col-sm-4 col-xs-12">

                        {isNew}

                        {isSalePercent}

                        <div className="product-img">
                            <a href="#">
                                <img className="primary-img" src={primaryImgUrl} alt="Product" />
                                <img className="secondary-img" src={secondaryImgUrl} alt="Product" />
                            </a>
                        </div>
                    </div>
                    <div className="col-md-9 col-sm-8 col-xs-12">
                        <div className="product-description">
                            <h5><a href="#">{prod.Name}</a></h5>
                            <div className="price-box">
                                <span className="price">$ {prod.Price}</span>
                                <span className="old-price">$ {prod.OldPrice}</span>
                            </div>
                            <p className="description">{prod.Description}</p>
                            <div className="product-action">
                                <div className="button-group">
                                    <div className="product-button">
                                        <button><i className="fa fa-shopping-cart"></i> Add to Cart</button>
                                    </div>
                                    <div className="product-button-2">
                                        <a onClick={this.openModalHandler} href="#" className="modal-view" id={
prod.ProductId} data-toggle="modal" data-target="#productModal"
                                           title="Quickview"><i className="fa fa-search-plus"></i></a>
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
            </div>);
        });
    } 

    return (
        <div className="listview">
            {result}
        </div>  
    );
}

}

导出默认列表；

为什么会发生这种情况，谁能解释一下？