关于模型验证那点事儿

今天应笑笑老师之问，做了一个模型验证的例子，发现之前对这个东西的理解太片面，重新整理了一下思路

字段验证优先级高于类验证

什么是类验证呢？就是两个字段组合的验证，比如你Admin不允许修改密码，你修改密码的Model在后端判断字段是不是Admin，并且密码的md5是不是特定的，我只是举例子啊，这样的验证，优先级是低于字段的验证的，字段验证通过，才会触发这个验证

验证的通用部分代码抄袭自刘总

刘总博客园链接附上https://www.cnblogs.com/lwc1st/

    public class ModelStateResult{public bool IsValid { get; }public List<ValidationResult> ValitionResultList { get; }public ModelStateResult(bool isValid, List<ValidationResult> valitionResultList){IsValid = isValid;ValitionResultList = valitionResultList;}}public static class ValitionExtension{public static ModelStateResult Valition<TEntity>(this TEntity entity) where TEntity:class,new(){var valitionResultList = new List<ValidationResult>();var context = new ValidationContext(entity, null, null);var isValidate = Validator.TryValidateObject(entity, context, valitionResultList, true);return new ModelStateResult(isValidate, valitionResultList);}}

我们先写一个实体对象的常规验证

    public class UserInfo{[Required]public string User { get; set; }[StringLength(32, MinimumLength = 10)]public string Password { get; set; }public string PhoneNumber { get; set; }}

验证部分代码附上

            UserInfo testEntity = new UserInfo(){User = null,Password = "123",PhoneNumber = "123456"};var testResult = testEntity.Valition();

我们看看执行结果

我们再添加一个，判断是否Admin的验证

    public class UserInfoValidation{public static ValidationResult IsAdmin(object value, ValidationContext validationContext){if (value is UserInfo userInfo){if (userInfo.User.Equals("Admin")){var isValidate = userInfo.Password.Equals("12345678901");if (!isValidate){return new ValidationResult("User Is Admin, Password Check Error");}}}return ValidationResult.Success;}}

在实体对象上打上CustomValidation特性，会提示是两个参数，第一个就是实现了自定义验证的类的Type，第二个参数是方法名

完整的实体对象代码为

   [CustomValidation(typeof(UserInfoValidation), "IsAdmin")]public class UserInfo{[Required]public string User { get; set; }[StringLength(32, MinimumLength = 10)]public string Password { get; set; }public string PhoneNumber { get; set; }}

再写一个测试代码

            var entity = new UserInfo(){User = "Admin",Password = "1234567890",PhoneNumber = "18382986022"};var validateResult = entity.Valition();

附上测试结果

特别注意一点，这个类的模型验证是低于字段的模型验证的，所以字段验证不通过，这里是不触发的，切记