netCore WebAPI基础2

API传参

在操作方法的参数前面使用Attribute

幂等性

对请求的数据验证

简单验证

using System.ComponentModel.DataAnnotations;
public class TouristRouteForCreationDto
{
        [Required(ErrorMessage ="title不能为空")]
        [MaxLength(1500)]
        public string Title { get; set; }
        [Required]
        [MaxLength(1500)]
        public string Description { get; set; }
}

属性级别验证

//增加验证Title和Description不能相同
using System.ComponentModel.DataAnnotations;
public class TouristRouteForCreationDto:IValidatableObject
{
        [Required(ErrorMessage ="title不能为空")]
        [MaxLength(1500)]
        public string Title { get; set; }
        [Required]
        [MaxLength(1500)]
        public string Description { get; set; }
   		public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
        {
            if (Title == Description)
            {
                //yield return 保证ValidationResult后面的代码，下次调用还会继续执行
                //TouristRouteForCreationDto代表错误路径
                yield return new ValidationResult("名称和描述不能相同", new[] { "TouristRouteForCreationDto"});
            }
        }
}

类级别验证

//创建Attribute
public class TouristRouteTitleMustBeDifferentFromDescriptionAttribute : ValidationAttribute
{
    protected override ValidationResult? IsValid(object? value, ValidationContext validationContext)
    {
        //获得实例
        var touristRouteDto = (TouristRouteForCreationDto)validationContext.ObjectInstance;
        if (touristRouteDto.Title == touristRouteDto.Description)
        {
            return new ValidationResult(
                 "路线名称必须与路线描述不同",
                 new[] { "TouristRouteForCreationDto" }
             );
        }
        return ValidationResult.Success;
    }
}


[TouristRouteTitleMustBeDifferentFromDescriptionAttribute]//应用属性
public class TouristRouteForCreationDto
{
        [Required(ErrorMessage ="title不能为空")]
        [MaxLength(1500)]
        public string Title { get; set; }
        [Required]
        [MaxLength(1500)]
        public string Description { get; set; }
}

验证失败返回422状态码

//在program中设置
builder.Services.AddControllers(opt => {
    opt.ReturnHttpNotAcceptable = true;//可以接收其他格式如xml
}).AddXmlDataContractSerializerFormatters()
.ConfigureApiBehaviorOptions(setupAction => {
    setupAction.InvalidModelStateResponseFactory = context =>
    {
        var problemDetail = new ValidationProblemDetails(context.ModelState)
        {
            Type = "无所谓",
            Title = "数据验证失败",
            Status = StatusCodes.Status422UnprocessableEntity,
            Detail = "请看详细说明",
            Instance = context.HttpContext.Request.Path //请求路径
        };
        problemDetail.Extensions.Add("traceId", context.HttpContext.TraceIdentifier);//追踪Id
        return new UnprocessableEntityObjectResult(problemDetail)
        {
            ContentTypes = { "application/problem+json" }
        };
    };
});