<PackageReference Include="System.ComponentModel.Annotations" Version="5.0.0-preview.5.20278.1" />

System.ComponentModel.DataAnnotations.ValidationAttribute

public abstract class ValidationAttribute : Attribute
public string ErrorMessage { get; set; }

public string ErrorMessageResourceName { get; set; }

public Type ErrorMessageResourceType { get; set; }

protected string ErrorMessageString { get; }

public virtual bool RequiresValidationContext { get; }

protected ValidationAttribute()

protected ValidationAttribute(string errorMessage)

protected ValidationAttribute(Func<string> errorMessageAccessor)

public virtual string FormatErrorMessage(string name)

public ValidationResult GetValidationResult(object value, ValidationContext validationContext)

public virtual bool IsValid(object value)

protected virtual ValidationResult IsValid(object value, ValidationContext validationContext)

public void Validate(object value, string name)

public void Validate(object value, ValidationContext validationContext)