.NET Core 验证过滤器

参考:

• https://code-maze.com/action-filters-aspnetcore/
• https://github.com/aspnet/AspNetCore.Docs/issues/12157
• https://docs.microsoft.com/en-us/aspnet/core/web-api/?view=aspnetcore-3.0#automatic-http-400-responses

1. 关闭默认模型验证过滤器
   [ApiController] 默认自带有 400 模型验证，且优先级比较高，如果需要自定义模型验证，则需要先关闭默认的模型验证
   在 StartUp.cs 中的 MVC 服务配置修改

   	#region MVC
   	services.AddMvc(o =>
   	{
   	}).SetCompatibilityVersion(CompatibilityVersion.Version_2_2)
   	.ConfigureApiBehaviorOptions(o =>
   	{
   	o.SuppressModelStateInvalidFilter = true;
   	});
   	#endregion

2. 首先定义统一输出的格式为

   	{
   	"code": "",
   	"errors":[
   	{
   	"filed":"",
   	"message":""
   	}
   	]
   	}

3. 添加自定义模型验证 DTO

   	public class ErrorResultDTO
   	{
   	/// <summary>
   	/// 参数领域
   	/// </summary>
   	public string Field { get; set; }
   	/// <summary>
   	/// 错误信息
   	/// </summary>
   	public string Message { get; set; }
   	}

4. 添加过滤器
   过滤器继承自：ActionFilterAttribute, IActionFilter

   	public class ModelActionFiter :ActionFilterAttribute, IActionFilter
   	{
   	public ModelActionFiter()
   	{
   	}
   	public override void OnActionExecuted(ActionExecutedContext context)
   	{
   	}
   	public override void OnActionExecuting(ActionExecutingContext context)
   	{
   	if (!context.ModelState.IsValid)
   	{
   	List<ErrorResultDTO> errorResults = new List<ErrorResultDTO>();
   	foreach (var item in context.ModelState)
   	{
   	var result = new ErrorResultDTO
   	{
   	Field = item.Key,
   	Msg = "",
   	};
   	foreach (var error in item.Value.Errors)
   	{
   	if (!string.IsNullOrEmpty(result.Msg))
   	{
   	result.Msg += '|';
   	}
   	result.Msg += error.ErrorMessage;
   	}
   	errorResults.Add(result);
   	}
   	context.Result = new BadRequestObjectResult(new
   	{
   	Code = StatusCodes.Status400BadRequest,
   	Errors = errorResults
   	});
   	}
   	}
   	}

5. 将写的过滤器注册到全局

   	services.AddMvc(o =>
   	{
   	o.Filters.Add(new ModelActionFiter());
   	})

6. 结果测试
   

7. 扩展

   • 利用拦截器来测试 action 的运行时间，记录日志，并设置时间限制，超过某个时间段自动发送邮件通知维护人员