C# Signature:

[DllImport("gdi32.dll")]
static extern int GetObject(IntPtr hgdiobj, int cbBuffer, IntPtr lpvObject);

VB.NET Signature:

<DllImport("gdi32.dll")> _
Private Shared Function GetObject(hgdiobj As IntPtr, cbBuffer As Integer, lpvObject As IntPtr) As Integer
End Function

User-Defined Types:

None.

Notes:

Had a terrible time getting this to work to retrieve a BITMAP object from a HBITMAP, this code finally worked.

(EDIT: Before going through all this check out the tips & tricks section for an official API to do this)

BITMAP bmpScreen;

GCHandle hndl = GCHandle.Alloc(bmpScreen, GCHandleType.Pinned);

IntPtr ptrToBitmap = hndl.AddrOfPinnedObject();

GDI32.GetObject(hBitmap, Marshal.SizeOf<GDI32.BITMAP>(), ptrToBitmap);

bmpScreen = Marshal.PtrToStructure<GDI32.BITMAP>(ptrToBitmap);

hndl.Free();

Tips & Tricks:

A better option than the above example would be to leverage Image.FromHbitmap

Image.FromHbitmap Documentation on MSDN: https://msdn.microsoft.com/en-us/library/k061we7x

Sample Code:

Please add some!

Alternative Managed API:

Do you know one? Please contribute it!