.net core ef json序列化循环引用问题

直接贴代码：

services.AddControllersWithViews()
    .AddNewtonsoftJson(options =>
    {
        options.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver(); //序列化时key为驼峰样式
        options.SerializerSettings.DateTimeZoneHandling = DateTimeZoneHandling.Local;
        options.SerializerSettings.DateFormatString = "yyyy-MM-dd HH:mm:ss";
        options.SerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;//忽略循环引用
    });