Use the SHFileOperation API to send a file or folder to the Recycle Bin. In the SHFILEOPSTRUCT that you pass to SHFileOperation, set the pFrom field to a string containing each file or folder path seperated by a null character. Make sure that there is an additional null character at the end of the pFrom string. This code is adapted from source code written by Jeff Key (author of Snippet Compiler).

private const int FO_DELETE          = 3;
private const int FOF_ALLOWUNDO      = 0x40;
private const int FOF_NOCONFIRMATION = 0x0010;

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto, Pack=1)]
public struct SHFILEOPSTRUCT
{
    public IntPtr hwnd;
    [MarshalAs(UnmanagedType.U4)] public int wFunc;
    public string pFrom;
    public string pTo;
    public short fFlags;
    [MarshalAs(UnmanagedType.Bool)] public bool fAnyOperationsAborted;
    public IntPtr hNameMappings;
    public string lpszProgressTitle;
}

[DllImport("shell32.dll", CharSet=CharSet.Auto)]
static extern int SHFileOperation(ref SHFILEOPSTRUCT FileOp);

...

SHFILEOPSTRUCT fileop = new SHFILEOPSTRUCT();
fileop.wFunc = FO_DELETE;
fileop.pFrom = filePath + '\0' + '\0';
fileop.fFlags = FOF_ALLOWUNDO | FOF_NOCONFIRMATION;

SHFileOperation(ref fileop);