报错如下:

设置的示例:

解决方案:
在Startup.cs文件中,增加如下代码:

services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2) .AddJsonOptions(options => { options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore; //json序列化时,避免死循环 options.SerializerSettings.ContractResolver = new Newtonsoft.Json.Serialization.DefaultContractResolver(); options.SerializerSettings.DateFormatString = "yyyy-MM-dd HH:mm:ss"; });