關于模型驗證那點事兒

今天應笑笑老師之問，做了一個模型驗證的例子，發現之前對這個東西的理解太片面，重新整理了一下思路

字段驗證優先級高于類驗證

什么是類驗證呢？就是兩個字段組合的驗證，比如你Admin不允許修改密碼，你修改密碼的Model在后端判斷字段是不是Admin，并且密碼的md5是不是特定的，我只是舉例子啊，這樣的驗證，優先級是低于字段的驗證的，字段驗證通過，才會觸發這個驗證

驗證的通用部分代碼抄襲自劉總

劉總博客園鏈接附上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);}}

我們先寫一個實體對象的常規驗證

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

驗證部分代碼附上

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

我們看看執行結果

我們再添加一個，判斷是否Admin的驗證

    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;}}

在實體對象上打上CustomValidation特性，會提示是兩個參數，第一個就是實現了自定義驗證的類的Type，第二個參數是方法名

完整的實體對象代碼為

   [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; }}

再寫一個測試代碼

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

附上測試結果

特別注意一點，這個類的模型驗證是低于字段的模型驗證的，所以字段驗證不通過，這里是不觸發的，切記