自定义验证 Attribute
- Attribute,IModelValidator
示例:ValidUrlAttribute
public class ValidUrlAttribute : Attribute, IModelValidator { public string ErrorMessage { get; set; } public IEnumerable<ModelValidationResult> Validate( ModelValidationContext context) { var url = context.Model as string; if (url != null && Uri.IsWellFormedUriString(url, UriKind.Absolute)) { return Enumerable.Empty<ModelValidationResult>(); } return new List<ModelValidationResult> { new ModelValidationResult(string.Empty, ErrorMessage) }; } }
使用时标注在 ViewModel 等实体类的属性上即可:
[Display(Name = "封面地址")] [Required(ErrorMessage = "{0}是必填项"), MaxLength(200, ErrorMessage = "{0}的长度不可超过{1}")] //[DataType(DataType.Url)] [ValidUrl(ErrorMessage = "这个URL不正确")] public string CoverUrl { get; set; }
远程验证
- [Remote]
- 客户端调用 Action 方法进行验证(前台调用后台验证)
Action 中的方法:
[AcceptVerbs("Get", "Post")] public async Task<IActionResult> CheckRoleExist([Bind("RoleName")]string roleName) { var role = await _roleManager.FindByNameAsync(roleName); if (role != null) return Json("角色已经存在了"); return Json(true); }
标注属性:
public class RoleAddViewModel { [Required] [Display(Name = "角色名称")] [Remote(nameof(RoleController.CheckRoleExist), "Role", ErrorMessage = "角色已存在")] public string RoleName { get; set; } }
注:暂时没找到更优雅的方法获取到 "Role"。