在 ASP.NET Core 中是否可以有多个仅因参数而异的 GET？

Question

我想构建真正的 RESTful 网络服务，所以不想利用 RPC 风格，所以目前有这个：

[HttpGet]
[ActionName(nameof(GetByParticipant))]
public async Task<IActionResult> GetByParticipant([FromQuery]string participantId, [FromQuery]string participantType, [FromQuery]string programName)
{
}

[HttpGet]
[ActionName(nameof(GetByProgram))]
public async Task<IActionResult> GetByProgram([FromQuery]string programName)
{
}

而且我相信这会在 ASP.NET Web API 中起作用。但我遇到了一个例外：

AmbiguousActionException: Multiple actions matched. The following actions matched route data and had all constraints satisfied:

TermsController.GetByParticipant (ParticipantTerms.Api)

TermsController.GetByProgram (ParticipantTerms.Api)

这两个属性都没有实际帮助：

[HttpGet]
[ActionName]
[FromQuery]

Answer 1

当使用 from query 时，你需要唯一区分动作的路由，否则你会得到 ambiguous action 异常。 api/action?participantId=1&participantType=2 的原因与 api/action?programName=x

相同

建议：

public class ParticipantQuery {
    public string participantId { get; set; } 
    public string participantType { get; set; }
    public string programName { get; set; }
}

[Route("api/[controller]")]
public class TermsController : Controller {

    [HttpGet("participants")]  //GET api/terms/participants?participantId=123&....
    [ActionName(nameof(GetByParticipant))]
    public async Task<IActionResult> GetByParticipant([FromQuery]ParticipantQuery model) {
        //...
    }

    [HttpGet("programs/{programName}")]//GET api/terms/programs/name
    [ActionName(nameof(GetByProgram))]
    public async Task<IActionResult> GetByProgram(string programName) {
        //...
    }
}

或者您可以使用一个封装可用参数的操作，并根据提供的成员对结果进行分支

public class GetTermsQuery {
    public string participantId { get; set; } 
    public string participantType { get; set; }
    public string programName { get; set; }
}

[Route("api/[controller]")]
public class TermsController : Controller {    
    [HttpGet]  //GET api/terms?participantId=123&....
    public async Task<IActionResult> Get([FromQuery]GetTermsQuery model) {
        //...
    }
}

Answer 2

您可以使用 IActionConstraint 执行此操作。

这是一个例子：

public class ExactQueryParamAttribute : Attribute, IActionConstraint
{
    private readonly string[] keys;

    public ExactQueryParamAttribute(params string[] keys)
    {
        this.keys = keys;
    }

    public int Order => 0;

    public bool Accept(ActionConstraintContext context)
    {
        var query = context.RouteContext.HttpContext.Request.Query;
        return query.Count == keys.Length && keys.All(key => query.ContainsKey(key));
    }
}

[HttpGet]
[ActionName(nameof(GetByParticipant))]
[ExactQueryParam("participantId", "participantType", "programName")]
public async Task<IActionResult> GetByParticipant([FromQuery]string participantId, [FromQuery]string participantType, [FromQuery]string programName)
{
}

[HttpGet]
[ActionName(nameof(GetByProgram))]
[ExactQueryParam("programName")]
public async Task<IActionResult> GetByProgram([FromQuery]string programName)
{
}

Answer 3

我花了一整天的时间来尝试执行此操作以及 Andrew Radford 的解决方案，这非常完美！

[HttpGet]
[ExactQueryParam("active")]
public IEnumerable<UserSelectAllSprocResult.DataRow> GetAll(
  [FromQuery] bool active)
{
  return ...
}

[HttpGet]
[ExactQueryParam("active", "companyId")]
public IEnumerable<UserSelectAllByCompanySprocResult.DataRow> GetByCompanyId(
  [FromQuery] bool active, [FromQuery] int companyId)
{
  return ...;
}

在 ASP.NET Core 中是否可以有多个仅因参数而异的 GET？

Is it possible to have multiple GETs that vary only by parameters in ASP.NET Core?

c#

.net-core

asp.net-core

asp.net-core-routing