CountPropertyHelper.cs

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using System.Collections;
using System.Diagnostics.CodeAnalysis;
using System.Reflection;
 
namespace System.ComponentModel.DataAnnotations;
 
internal static class CountPropertyHelper
{
    [RequiresUnreferencedCode("Uses reflection to get the 'Count' property on types that don't implement ICollection. This 'Count' property may be trimmed. Ensure it is preserved.")]
    public static bool TryGetCount(object value, out int count)
    {
        if (value is ICollection collection)
        {
            count = collection.Count;
            return true;
        }
        PropertyInfo runtimeProperty = value.GetType().GetRuntimeProperty("Count");
        if (runtimeProperty != null && runtimeProperty.CanRead && runtimeProperty.PropertyType == typeof(int))
        {
            count = (int)runtimeProperty.GetValue(value);
            return true;
        }
        count = -1;
        return false;
    }
}