Repository navigation
Invalid cast from 'WinRT.IInspectable' to 'IMemoryBufferByteAccess' (GeneratedComInterface) #1672
Description
It's basically this issue, but it only happens when I replace [ComImport] with [GeneratedComInterface].
Describe the bug
Given
[GeneratedComInterface]
[Guid("5B0D3235-4DBA-4D44-865E-8F1D0E4FD04D")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public unsafe partial interface IMemoryBufferByteAccess
{
void GetBuffer(out IntPtr buffer, out uint capacity);
}Attempting to convert IMemoryBufferReference reference to IMemoryBufferByteAccess fails with
System.InvalidCastException: 'Invalid cast from 'WinRT.IInspectable' to 'ChatGPT.Platforms.Windows.Core.IMemoryBufferByteAccess'.'
To Reproduce
See the linked issue
IMemoryBufferReference reference = ...reference.As<IMemoryBufferByteAccess>()
Expected behavior
Should get IMemoryBufferByteAccess
Version Info
.NET SDK 8.0 - net8.0-windows10.0.22621.0
Additional context
Activity
dongle-the-gadget commentedon Jul 14, 2024
GeneratedComInterfaceisn’t allowed right now as the NuGet version does not contain the .NET 8WinRT.Runtimethat contains this functionality.Sergio0694 commentedon Jul 15, 2024
Yeah this is caused by the fact we're not shipping the .NET 8 TFM yet, so this is expected. That said, it definitely shouldn't be needed to manually define
IMemoryBufferByteAccess, do interop with that interface and use that directly just to get data out of anIMemoryBufferReferenceinstance. I've opened #1673 to add a helper API to do this much more easily (and efficiently) 🙂