/*
* 1.在Core Mvc中JsonResult 默认支持Get请求
* 2.使用JQuery的ajax请求，返回json数据自动转换成 object对象
* 3.在 Core Mvc的 后台JsonResult序列化的时候，默认情况下自动 处理 的命名规则，改成了 js的驼峰格式
* 4.在 Core Mvc中json 的序列化发序列化使用的是Newtonsoft.Json库
* 5.默认没有处理循环引用的问题
*/

$(‘#btnOne‘).click(function () {
    //使用ajax get请求json 数据
    $.get(‘@Url.Action("DataOne")‘, {}, function (data) {
        console.info(data);
        console.info(data[0].menuName);
    });
});

public JsonResult DataThree()
{
    //Ef Core现在 不支持延迟加载，对于关联表数据都为null
    List<Menu> menus = _context.Menu
        .ToList();
    return Json(menus);
}

public JsonResult DataOne()
{
    List<Menu> menus = _context.Menu.ToList();
    JsonSerializerSettings settings = new JsonSerializerSettings();
    //EF Core中默认为驼峰样式序列化处理key
    //settings.ContractResolver = new CamelCasePropertyNamesContractResolver();
    //使用默认方式，不更改元数据的key的大小写
    settings.ContractResolver = new DefaultContractResolver();

    return Json(menus, settings);
}

public JsonResult DataTwo()
{
    List<Menu> menus = _context.Menu
        .Include(q => q.Model)
        .ToList();
    //处理循环引用问题
    JsonSerializerSettings settings = new JsonSerializerSettings();
    settings.MaxDepth = 2;
    settings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore; //设置不处理循环引用
    return Json(menus, settings);
}

    //
    // 摘要:
    //     Extensions methods for configuring MVC via an Microsoft.Extensions.DependencyInjection.IMvcBuilder.
    public static class MvcJsonMvcBuilderExtensions
    {
        //
        // 摘要:
        //     Adds configuration of Microsoft.AspNetCore.Mvc.MvcJsonOptions for the application.
        //
        // 参数:
        //   builder:
        //     The Microsoft.Extensions.DependencyInjection.IMvcBuilder.
        //
        //   setupAction:
        //     The Microsoft.AspNetCore.Mvc.MvcJsonOptions which need to be configured.
        public static IMvcBuilder AddJsonOptions(this IMvcBuilder builder, Action<MvcJsonOptions> setupAction);
    }

    //
    // 摘要:
    //     Provides programmatic configuration for JSON in the MVC framework.
    public class MvcJsonOptions
    {
        public MvcJsonOptions();

        //
        // 摘要:
        //     Gets the Newtonsoft.Json.JsonSerializerSettings that are used by this application.
        public JsonSerializerSettings SerializerSettings { get; }
    }

// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
    // Add framework services.
    services.AddMvc()
        //全局配置Json序列化处理
        .AddJsonOptions(options =>
        {
            //忽略循环引用
            options.SerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
            //不使用驼峰样式的key
            options.SerializerSettings.ContractResolver = new DefaultContractResolver();
            //设置时间格式
            options.SerializerSettings.DateFormatString = "yyyy-MM-dd";
        }
        );
}