Validator.TryValidateObject Not Validating RangeAttribute

Question

Given the following object,

public class Question
{
    [Required]
    public string QuestionText { get; set; }

    [Range(1, 5)]
    public int Difficulty { get; set; }        
}

With the following Validation Code

ICollection<ValidationResult> results = new List<ValidationResult>();
Question question = new Question();
ValidationContext ctx = new ValidationContext(question, null, null);
Validator.TryValidateObject(question, ctx, results);
// results.Length = 1

Why does Range attribute not create a validation error when Required does (the value is 0 obviously)?

James Hughes · Accepted Answer · 2011-03-20T19:38:24.037

79

Ah so it would seem I need to specify validateAllProperties = true

Validator.TryValidateObject(question, ctx, results, true);

Incidentally what was throwing me off was the fact I had an abstract base class with another property in it and without validateAllProperties the Validator will stop on the first error of ALL superclasses too. So you will get a validation error for each superclass (in my case 2)

edited Mar 20 '11 at 19:38

answered Mar 20 '11 at 13:35

James Hughes

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The original post is nearly 3 years old, I'd expect some drift in behaviour. – James Hughes Jan 14 '14 at 15:38
Turned out my problem was slightly different - http://stackoverflow.com/questions/21111905/validator-tryvalidateobject-does-not-validate-attribute – Jochen van Wylick Jan 22 '14 at 13:27
Still works for me 6 years later - behaviour hasn't drifted that much, and still a surprise to me that the default is `false`. – David Clarke Jun 07 '17 at 07:06
2

Goodness. I can't believe `true` isn't the default for this. What a headache. Thank you – user1447679 May 01 '18 at 21:41
I feel this is as appropriate of an API choice as having a method called ShouldExecuteCode. Thanks, I missed this. – Billy Jake O'Connor Sep 17 '21 at 15:45
For those who are using dotnet 6 and still getting issue: https://github.com/dotnet/runtime/issues/64736 – Pratap Singh Mehra Jul 19 '23 at 12:20

score 23 · Answer 2 · answered Nov 23 '11 at 15:07

23

Validator.TryValidatorObject(instance, validationContext, validationResults) calls Validator.TryValidateObject(instance, validationContext, validationResults, validateAllProperties) with validateAllProperties = false.

When validateAllProperties is false, only the RequiredAttribute will be validated.

answered Nov 23 '11 at 15:07

Smartkid

1,772
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6

My goodness what a mess is this. Hope Microsoft understand there is something called as the word "user friendly". – Shivprasad Koirala May 11 '15 at 07:04
That is not intuitive at all. :( – Kjensen Jun 20 '18 at 05:59

Validator.TryValidateObject Not Validating RangeAttribute

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