How do I get the collection of Model State Errors in ASP.NET MVC?

Question

How do I get the collection of errors in a view?

I don\'t want to use the Html Helper Validation Summary or Validation Message. Instead I want to check for errors an

Answer 1

To just get the errors from the ModelState, use this Linq:

var modelStateErrors = this.ModelState.Keys.SelectMany(key => this.ModelState[key].Errors);

Answer 2

This will give you one string with all the errors with comma separating

string validationErrors = string.Join(",",
                    ModelState.Values.Where(E => E.Errors.Count > 0)
                    .SelectMany(E => E.Errors)
                    .Select(E => E.ErrorMessage)
                    .ToArray());

Answer 3

<% ViewData.ModelState.IsValid %>

or

<% ViewData.ModelState.Values.Any(x => x.Errors.Count >= 1) %>

and for a specific property...

<% ViewData.ModelState["Property"].Errors %> // Note this returns a collection

Answer 4

Here is the VB.

Dim validationErrors As String = String.Join(",", ModelState.Values.Where(Function(E) E.Errors.Count > 0).SelectMany(Function(E) E.Errors).[Select](Function(E) E.ErrorMessage).ToArray())

Answer 5

Got this from BrockAllen's answer that worked for me, it displays the keys that have errors:

    var errors =
    from item in ModelState
    where item.Value.Errors.Count > 0
    select item.Key;
    var keys = errors.ToArray();

Source: https://forums.asp.net/t/1805163.aspx?Get+the+Key+value+of+the+Model+error

Answer 6

Thanks Chad! To show all the errors associated with the key, here's what I came up with. For some reason the base Html.ValidationMessage helper only shows the first error associated with the key.

    <%= Html.ShowAllErrors(mykey) %>

HtmlHelper:

    public static String ShowAllErrors(this HtmlHelper helper, String key) {
        StringBuilder sb = new StringBuilder();
        if (helper.ViewData.ModelState[key] != null) {
            foreach (var e in helper.ViewData.ModelState[key].Errors) {
                TagBuilder div = new TagBuilder("div");
                div.MergeAttribute("class", "field-validation-error");
                div.SetInnerText(e.ErrorMessage);
                sb.Append(div.ToString());
            }
        }
        return sb.ToString();
    }