值得一提的是，ASP.NET Core 2.1添加了[ApiController]属性，该属性通过返回一个BadRequestObjectResult来自动处理模型验证错误. ModelState传入.换句话说，如果用该属性装饰控制器，则不再需要进行if (!ModelState.IsValid)检查.

It's worth mentioning that ASP.NET Core 2.1 added the [ApiController] attribute, which among other things, automatically handles model validation errors by returning a BadRequestObjectResult with ModelState passed in. In other words, if you decorate your controllers with that attribute, you no longer need to do the if (!ModelState.IsValid) check.

此外，该功能也是可扩展的.在Startup中，您可以添加:

Additionally, the functionality is also extensible. In Startup, you can add:

services.Configure<ApiBehaviorOptions>(o =>
{
    o.InvalidModelStateResponseFactory = actionContext =>
        new BadRequestObjectResult(actionContext.ModelState);
});

以上是默认情况下已经发生的事情，但是您可以在其中设置InvalidModelStateResponseFactory的lambda进行自定义，以返回所需的内容.

The above is just what already happens by default, but you can customize the lambda there that InvalidModelStateResponseFactory is set to in order to return whatever you like.