c# - 在 .NET Core 2.0 中接受 API 的多个参数

Question

在这里我总是得到 null。

我如何在 .Net Core 中创建一个端点来接受两个 POCO？仅使用一个对象一切正常。

[HttpPost]
[Route("Checkout")]
public IActionResult Checkout([FromBody]Order order, [FromBody]Cart cart)
{            
    return Ok();
}

Answer 1

你不能有两个[FromBody]参数，the documentation对此非常清楚:

There can be at most one parameter per action decorated with [FromBody]. The ASP.NET Core MVC run-time delegates the responsibility of reading the request stream to the formatter. Once the request stream is read for a parameter, it's generally not possible to read the request stream again for binding other [FromBody] parameters.

通常，您会有一个数据传输对象 (DTO)/ViewModel (VM)，其中包含您需要的所有数据:

public class CheckOutViewModel
{
    public Order Order { get; set; }
    public Cart Cart { get; set; }
}

然后您将使用该模型进行绑定(bind):

[HttpPost]
[Route("Checkout")]
public IActionResult Checkout([FromBody]CheckOutViewModel checkout)
{            
    return Ok();
}