验证 Valid

自定义验证特性

using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;

namespace MvcMovie.Validations
{
    /// <summary>
    /// 自定义验证Url特性
    /// </summary>
    public class ValidUrlAttribute : Attribute, IModelValidator
    {
        public string ErrorMessage { get; set; } = "无效的Url";
        public ValidUrlAttribute()
        {

        }
        public　ValidUrlAttribute(string errorMessage)
        {
            ErrorMessage = errorMessage;
        }
        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)
            };
        }
    }
}

Model模型使用：

 [ValidUrl(ErrorMessage ="Url不正确")]
public string? ConverUrl { get; set; }

效果：

　

远程验证 Remote

客户端调用 Action 方法进行验证

Model 模型添加远程验证特性

 [Remote(nameof(UserController.CheckUserExist), "User",ErrorMessage ="用户已存在")]
 public string UserName { get; set; }

在 UserController 控件器中定义远程验证类：

[AcceptVerbs("Get", "Post")]
        public async Task<IActionResult> CheckUserExist([Bind(nameof(UserCreateViewModel.UserName))] string userName)
        {
            var user = await m_UserManager.Users.FirstOrDefaultAsync(x => x.UserName == userName);
            if (user == null)
            {
                return Json(true);
            }
            else
            {
                return Json("用户已经存在");
            }
        }

　注意：必须在 View  底部添加脚本

@section Scripts {
    @{
        await Html.RenderPartialAsync("_ValidationScriptsPartial");
    }
}