AddJsonOptions()将
System.Text.Json仅配置为MVC。如果要
JsonSerializer在自己的代码中使用，则应将配置传递给它。
var options = new JsonSerializerOptions{ PropertyNamingPolicy = JsonNamingPolicy.CamelCase,};var json = "{"firstname":"John","lastname":"Smith"}";var person = JsonSerializer.Parse<Person>(json, options);
