c# - 是否可以有多个仅因 ASP.NET Core 中的参数而异的 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。但我遇到了一个异常(exception):

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

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)
{
}