如何正确处理 ASP.Net Core 3 Web API 中的多个端点答案

【问题标题】：How to handle multiple endpoints in ASP.Net Core 3 Web API properly如何正确处理 ASP.Net Core 3 Web API 中的多个端点
【发布时间】：2019-09-29 16:19:07
【问题描述】：

我有两种方法来处理 HTTP GET 请求，第一种用于int 类型输入，另一种用于string 类型输入。

//GET : api/Fighters/5
[HttpGet("{id}")]
public async Task<ActionResult<Fighter>> GetFighter(int id) 
{
    var fighter = await _context.Fighters.FindAsync(id);

    if (fighter == null) 
    {
        return NotFound();
    }
    return fighter;
}

// GET: api/Fighters/Alex
[Route("api/Fighters/{name}")]
[HttpGet("{name}")]
public async Task<ActionResult<IEnumerable<Fighter>>> GetFighter (string name) 
{
    return await _context.Fighters.Where(f => f.Name == name).ToListAsync();
}

当我发送 HTTP GET 时出现此异常（在 Postman 中）：

Microsoft.AspNetCore.Routing.Matching.AmbiguousMatchException: The request matched multiple endpoints. Matches: 

FighterGameService.Controllers.FightersController.GetFighter (FighterGameService)
FighterGameService.Controllers.FightersController.GetFighter (FighterGameService)
FighterGameService.Controllers.FightersController.GetFighter (FighterGameService)
FighterGameService.Controllers.FightersController.GetFighter (FighterGameService)
   at Microsoft.AspNetCore.Routing.Matching.DefaultEndpointSelector.ReportAmbiguity(CandidateState[] candidateState)
   at Microsoft.AspNetCore.Routing.Matching.DefaultEndpointSelector.ProcessFinalCandidates(HttpContext httpContext, CandidateState[] candidateState)
   at Microsoft.AspNetCore.Routing.Matching.DefaultEndpointSelector.Select(HttpContext httpContext, CandidateState[] candidateState)
   at Microsoft.AspNetCore.Routing.Matching.DfaMatcher.MatchAsync(HttpContext httpContext)
   at Microsoft.AspNetCore.Routing.Matching.DataSourceDependentMatcher.MatchAsync(HttpContext httpContext)
   at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext httpContext)
   at Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.HttpsPolicy.HttpsRedirectionMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

GET api/fighters/1 显然会导致错误，因为“1”可能是int 或string，所以我通过结合两种方法解决了我的问题：

// GET: api/Fighters/5
// GET: api/Fighters/Alex
[HttpGet("{idOrName}")]
public async Task<ActionResult<IEnumerable<Fighter>>> GetFighter(string idOrName)
{
    if (Int32.TryParse(idOrName, out int id))
    {
        return await _context.Fighters.Where(f => f.Id == id).ToListAsync();
    }
    else
    {
        return await _context.Fighters.Where(f => f.Name == idOrName).ToListAsync();
    }

}

这行得通，但感觉根本不对。处理这个问题的正确方法是什么？

【问题讨论】：

标签： c# asp.net-core asp.net-core-webapi asp.net-core-3.0

【解决方案1】：

你可以使用route constraint

[HttpGet("{id:int}")]
public async Task<ActionResult<Fighter>> GetFighter(int id) 

[HttpGet("{name}")]
public async Task<ActionResult<IEnumerable<Fighter>>> GetFighter (string name)

【讨论】：

【解决方案2】：

我在 Core 3.0 中遇到过这个问题。我终于发现解决方案是在动作上放置一个路由属性 - 例如[Route("NodeInfo")]。解决了它

【讨论】：

至少当您有一个具有相同签名的端点时，这是正确的答案

【解决方案3】：

请按照.Net Core 3.1或更高版本的解决方案：使用[Route("RouteName")]

[HttpPost]
        [Route("CreateUserRole")]
       // [Authorize(Roles = "admin")]
        [ProducesResponseType(StatusCodes.Status201Created)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        [ProducesResponseType(StatusCodes.Status500InternalServerError)]
        public async Task<IActionResult> CreateUserRole([FromBody] AssignUserRole assignUserRole)
        {
            try
            {
                _logger.LogInfo("Attempted submission attempted");

                if (assignUserRole == null)
                {
                    _logger.LogWarn("Empty request submitted");
                    return BadRequest(ModelState);
                }
                if (!ModelState.IsValid)
                {
                    _logger.LogWarn("User data was incomplete");
                    return BadRequest(ModelState);
                }
                var User = _Mapper.Map<Users>(assignUserRole);
                _UserRoleRepository.AssignRoleUser(assignUserRole);
                _logger.LogInfo("User Role created");
                Audit_logs audit = new Audit_logs()
                {
                    uid = User.id,
                    action = "Create User Role",
                    log = $"{assignUserRole.rolename} Role has created",
                    datetime = DateTime.Now
                };
                await _audit_Logs.Create(audit);
                return Created("Create User Role", new { assignUserRole });
            }
            catch (Exception ex)
            {
                return InternalError($"{ex.Message}-{ex.InnerException}");
            }

        }

【讨论】：