C# Definition:

For 32-bit processes:

[StructLayout(LayoutKind.Sequential, Pack = 1, CharSet = CharSet.Auto)]
public struct SHFILEOPSTRUCT
{
   public IntPtr hwnd;
   public uint wFunc;
   [MarshalAs(UnmanagedType.LPTStr)]
   public string pFrom;
   [MarshalAs(UnmanagedType.LPTStr)]
   public string pTo;
   public ushort fFlags;
   public bool fAnyOperationsAborted;
   public IntPtr hNameMappings;
   [MarshalAs(UnmanagedType.LPTStr)]
   public string lpszProgressTitle;
}

For 64-bit processes:

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public struct SHFILEOPSTRUCT
{
   public IntPtr hwnd;
   public uint wFunc;
   [MarshalAs(UnmanagedType.LPTStr)]
   public string pFrom;
   [MarshalAs(UnmanagedType.LPTStr)]
   public string pTo;
   public ushort fFlags;
   public bool fAnyOperationsAborted;
   public IntPtr hNameMappings;
   [MarshalAs(UnmanagedType.LPTStr)]
   public string lpszProgressTitle;
}

VB.NET Definition

For 32-bit processes:

<StructLayout(LayoutKind.Sequential, Pack:=1, CharSet:=CharSet.Auto)> _
Public Structure SHFILEOPSTRUCT
     Public hwnd As IntPtr
     <MarshalAs(UnmanagedType.U4)>Public wFunc As FileFuncFlags
     <MarshalAs(UnmanagedType.LPTStr)>Public pFrom As String
     <MarshalAs(UnmanagedType.LPTStr)>Public pTo As String
     <MarshalAs(UnmanagedType.U2)>Public fFlags As FILEOP_FLAGS
     <MarshalAs(UnmanagedType.Bool)>Public fAnyOperationsAborted As Boolean
     Public hNameMappings As IntPtr
     <MarshalAs(UnmanagedType.LPTStr)>Public lpszProgressTitle As String '  only used if FOF_SIMPLEPROGRESS
End Structure    

For 64-bit processes:

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Auto)> _
Public Structure SHFILEOPSTRUCT
     Public hwnd As IntPtr
     <MarshalAs(UnmanagedType.U4)>Public wFunc As FileFuncFlags
     <MarshalAs(UnmanagedType.LPTStr)>Public pFrom As String
     <MarshalAs(UnmanagedType.LPTStr)>Public pTo As String
     <MarshalAs(UnmanagedType.U2)>Public fFlags As FILEOP_FLAGS
     <MarshalAs(UnmanagedType.Bool)>Public fAnyOperationsAborted As Boolean
     Public hNameMappings As IntPtr
     <MarshalAs(UnmanagedType.LPTStr)>Public lpszProgressTitle As String '  only used if FOF_SIMPLEPROGRESS
End Structure    

VB Definition:

Public Type SHFILEOPSTRUCT
     hWnd As Long
     wFunc As FileFuncFlags
     pFrom As String
     pTo As String
     fFlags As FILEOP_FLAGS
     fAnyOperationsAborted As Long
     hNameMappings As Long
     lpszProgressTitle As String
End Type

User-Defined Field Types:

FileFuncFlags, FILEOP_FLAGS

Notes:

The definitions above are the same used by Microsoft.VisualBasic.CompilerServices in the Microsoft.VisualBasic.dll. The difference is that for 32-bit processes the struct fields must be packed without alignment (Pack=1), whereas for 64-bit processes the default alignment must be used.

To check if your process uses 32-bit or 64-bit, do sizeof(IntPtr) which will return 4 for 32-bit processes or 8 for 64-bit processes.

Alternative Managed API:

You may use the functionality of the Microsoft.VisualBasic.dll/Nuget package: (.NET framework) instead:

using Microsoft.VisualBasic.FileIO;
FileSystem.DeleteFile(path, UIOption.OnlyErrorDialogs, RecycleOption.SendToRecycleBin);