net6.0-windows 
namespace Microsoft.AspNetCore.Mvc.ModelBinding
{
    [DefaultMember("Item")]
    public class ModelStateDictionary : IEnumerable<KeyValuePair<string, ModelStateEntry>>, IReadOnlyCollection<KeyValuePair<string, ModelStateEntry>>, IReadOnlyDictionary<string, ModelStateEntry>, IEnumerable
    {
        public int Count { get; }
    }
}
nuget.org
0.0 %
Reference this API
.NET 5.06.07.08.09.010.0
.NET Core 2.02.12.23.03.1
.NET Framework 4.6.14.6.24.74.7.14.7.24.84.8.1
.NET Standard 2.02.1
Information specific to net6.0
Assembly

Microsoft.AspNetCore.Mvc.Abstractions , Version=2.3.0.0, PublicKeyToken=adb9793829ddae60

Referencing

Your project needs a package reference to Microsoft.AspNetCore.Mvc.Abstractions.

Package Microsoft.AspNetCore.Mvc.Abstractions (2.3.0) netstandard2.0
Platform Restrictions

The property getter is supported on all platforms.

  • Built-in API
  • Package-provided API