ASP.NET Core modelbinder 将请求正文绑定到模型的一个属性

Question

I'm trying to bind this request body to the Data property of class CreateCommand :

public class CreateCommand<TCommand, TEntity> : IRequest<int>
    where TCommand : ICommand
    where TEntity : Entity, IAggregateRoot
{
    [FromBody] // this attribute is not working.
    public TCommand Data { get; set; }
    public CreateCommand() { }
}

[HttpPost]
public async Task<ActionResult<TicketVM1>> PostProduce(CreateCommand<TicketV1Command, Produce> createCommond)
{
    var id = await _mediator.Send(createCommond);

    return CreatedAtAction("GetProduce", new { id = id });
}

Can I use property as the root of request body?

Answer 1

To successfully achieve this binding move the attribute to method signature

public class CreateCommand<TCommand, TEntity> : IRequest<int>
    where TCommand : ICommand
    where TEntity : Entity, IAggregateRoot
{
    public TCommand Data { get; set; }
    public CreateCommand() { }
}

[HttpPost]
public async Task<ActionResult<TicketVM1>> PostProduce([FromBody]CreateCommand<TicketV1Command, Produce> createCommond)
{
    var id = await _mediator.Send(createCommond);

    return CreatedAtAction("GetProduce", new { id = id });
}

Now when posting data make sure to encapsulate it all inside a data object. This may become your final body

{
   "Data":
   {
      "Foo": "bar"
   }
}

You can however bind to it directly by:

public async Task<ActionResult<TicketVM1>> PostProduce([FromBody]CreateCommand<TicketV1Command, Produce>.Data createCommond)

now you can post data as-is

{
    "Foo": "Bar"
}