Inconsistency in the description of the called method in the documentation and in the source code (refers to the return type).
Type of issue
Code doesn't work
Description
There is a contradiction in the description of the called method in the documentation and in the source code: in the source code, for called methods with one or two input parameters, there is always one return type - ValidationResult, while the documentation states that a method with one parameter must return the Boolean type.
Source code (from Git):
/// summary
/// Validation attribute that executes a user-supplied method at runtime, using one of these signatures:
/// public static /summary
public sealed class CustomValidationAttribute : ValidationAttribute
[ . . . ]
// Invoke the method. Catch TargetInvocationException merely to unwrap it. // Callers don't know Reflection is being used and will not typically see // the real exception try { // 1-parameter form is ValidationResult Method(object value) // 2-parameter form is ValidationResult Method(object value, ValidationContext context), var methodParams = _isSingleArgumentMethod ? new object?[] { convertedValue } : new[] { convertedValue, validationContext };
var result = (ValidationResult?)methodInfo!.Invoke(null, methodParams);
[ . . . ]
// Method must return a ValidationResult or derived class if (!typeof(ValidationResult).IsAssignableFrom(methodInfo.ReturnType)) { return SR.Format(SR.CustomValidationAttribute_Method_Must_Return_ValidationResult, Method, ValidatorType.Name); }
[ . . . ]
// We accept 2 forms: // 1-parameter form is ValidationResult Method(object value) // 2-parameter form is ValidationResult Method(object value, ValidationContext context), _isSingleArgumentMethod = (parameterInfos.Length == 1);
[ . . . ]
Page URL
https://learn.microsoft.com/en-us/dotnet/api/system.componentmodel.dataannotations.customvalidationattribute.method?view=net-9.0
Content source URL
https://github.com/dotnet/dotnet-api-docs/blob/main/xml/System.ComponentModel.DataAnnotations/CustomValidationAttribute.xml
Document Version Independent Id
ba1cc98b-e6b7-bf0a-9307-d450b7ff2a35
Article author
@dotnet-bot
Tagging subscribers to this area: @ajcvickers
This issue is also a duplicate of #3126.