EnumeratorToEnumVariantMarshaler.cs

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using System.Collections;
using System.Runtime.InteropServices.ComTypes;
using System.Runtime.Versioning;
 
namespace System.Runtime.InteropServices.CustomMarshalers;
 
[SupportedOSPlatform("windows")]
internal sealed class EnumeratorToEnumVariantMarshaler : ICustomMarshaler
{
    private static readonly EnumeratorToEnumVariantMarshaler s_enumeratorToEnumVariantMarshaler = new EnumeratorToEnumVariantMarshaler();
 
    public static ICustomMarshaler GetInstance(string cookie)
    {
        return s_enumeratorToEnumVariantMarshaler;
    }
 
    private EnumeratorToEnumVariantMarshaler()
    {
    }
 
    public void CleanUpManagedData(object ManagedObj)
    {
    }
 
    public void CleanUpNativeData(IntPtr pNativeData)
    {
        Marshal.Release(pNativeData);
    }
 
    public int GetNativeDataSize()
    {
        return -1;
    }
 
    public IntPtr MarshalManagedToNative(object ManagedObj)
    {
        if (ManagedObj == null)
        {
            throw new ArgumentNullException("ManagedObj");
        }
        if (ManagedObj is EnumeratorViewOfEnumVariant enumeratorViewOfEnumVariant)
        {
            return Marshal.GetComInterfaceForObject<object, IEnumVARIANT>(enumeratorViewOfEnumVariant.GetUnderlyingObject());
        }
        EnumVariantViewOfEnumerator o = new EnumVariantViewOfEnumerator((System.Collections.IEnumerator)ManagedObj);
        return Marshal.GetComInterfaceForObject<EnumVariantViewOfEnumerator, IEnumVARIANT>(o);
    }
 
    public object MarshalNativeToManaged(IntPtr pNativeData)
    {
        if (pNativeData == IntPtr.Zero)
        {
            throw new ArgumentNullException("pNativeData");
        }
        object objectForIUnknown = Marshal.GetObjectForIUnknown(pNativeData);
        if (!objectForIUnknown.GetType().IsCOMObject)
        {
            if (objectForIUnknown is EnumVariantViewOfEnumerator enumVariantViewOfEnumerator)
            {
                return enumVariantViewOfEnumerator.Enumerator;
            }
            return objectForIUnknown as System.Collections.IEnumerator;
        }
        return ComDataHelpers.GetOrCreateManagedViewFromComData(objectForIUnknown, (IEnumVARIANT var) => new EnumeratorViewOfEnumVariant(var));
    }
}