Get selected files from Desktop

Question

I'm trying to get a list of selected files from the Desktop. I get the correct amount of files, but I get weird file names like this for example:㺘ݔ䁐\†\ . I'm using the LVM_GETITEM message to get the info. This is my code:

        public string GetItemText(int idx)
        {
            const int MAX_SIZE = 512;
            byte[] szBuffer = new byte[MAX_SIZE];

            LVITEM lvi = new LVITEM
            {
                mask = LVIF_TEXT,
                cchTextMax = MAX_SIZE,
                iItem = idx,
                iSubItem = 0,
                pszText = Marshal.AllocHGlobal(MAX_SIZE)
            };

            // Fill LVITEM structure
            IntPtr ptrLvi = Marshal.AllocHGlobal(Marshal.SizeOf(lvi));
            Marshal.StructureToPtr(lvi, ptrLvi, false);
            int readBytes = 0;
            try
            {
                readBytes = SendMessagePtr(ShellListViewHandle, LVM_GETITEM, IntPtr.Zero, ptrLvi);
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine(ex.Message);
            }

            // Get the text
            string itemText = Marshal.PtrToStringAuto(lvi.pszText);
            return itemText;
        }

Answer 1

You cannot do that using the Shell Objects for Scripting AFAIK. You can only start with it and then use native Shell interfaces.

This principles are explained here Manipulating the positions of desktop icons in C/C++.

Here is a similar C# Console app that dumps out all items names currently selected in the desktop, you'll have to adapt or expand depending on what you need:

public class Program
{
    static void Main()
    {
        // we basically follow https://devblogs.microsoft.com/oldnewthing/20130318-00/?p=4933
        dynamic app = Activator.CreateInstance(Type.GetTypeFromProgID("Shell.Application"));
        var windows = app.Windows;

        const int SWC_DESKTOP = 8;
        const int SWFO_NEEDDISPATCH = 1;
        var hwnd = 0;
        var disp = windows.FindWindowSW(Type.Missing, Type.Missing, SWC_DESKTOP, ref hwnd, SWFO_NEEDDISPATCH);

        var sp = (IServiceProvider)disp;
        var SID_STopLevelBrowser = new Guid("4c96be40-915c-11cf-99d3-00aa004ae837");

        var browser = (IShellBrowser)sp.QueryService(SID_STopLevelBrowser, typeof(IShellBrowser).GUID);
        var view = (IFolderView)browser.QueryActiveShellView();

        view.Items(SVGIO.SVGIO_SELECTION, typeof(IShellItemArray).GUID, out var items);
        if (items is IShellItemArray array)
        {
            for (var i = 0; i < array.GetCount(); i++)
            {
                var item = array.GetItemAt(i);
                Console.WriteLine(item.GetDisplayName(SIGDN.SIGDN_NORMALDISPLAY));
            }
        }
    }

    [Guid("6D5140C1-7436-11CE-8034-00AA006009FA"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    private interface IServiceProvider
    {
        [return: MarshalAs(UnmanagedType.IUnknown)]
        object QueryService([MarshalAs(UnmanagedType.LPStruct)] Guid service, [MarshalAs(UnmanagedType.LPStruct)] Guid riid);
    }

    // note: for the following interfaces, not all methods are defined as we don't use them here
    [Guid("000214E2-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    private interface IShellBrowser
    {
        void _VtblGap1_12(); // skip 12 methods https://stackoverflow.com/a/47567206/403671

        [return: MarshalAs(UnmanagedType.IUnknown)]
        object QueryActiveShellView();
    }

    [Guid("cde725b0-ccc9-4519-917e-325d72fab4ce"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    private interface IFolderView
    {
        void _VtblGap1_5(); // skip 5 methods

        [PreserveSig]
        int Items(SVGIO uFlags, Guid riid, [MarshalAs(UnmanagedType.IUnknown)] out object items);
    }

    [Guid("43826d1e-e718-42ee-bc55-a1e261c37bfe"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    private interface IShellItem
    {
        [return: MarshalAs(UnmanagedType.IUnknown)]
        object BindToHandler(System.Runtime.InteropServices.ComTypes.IBindCtx pbc, [MarshalAs(UnmanagedType.LPStruct)] Guid bhid, [MarshalAs(UnmanagedType.LPStruct)] Guid riid);

        IShellItem GetParent();

        [return: MarshalAs(UnmanagedType.LPWStr)]
        string GetDisplayName(SIGDN sigdnName);

        // 2 other methods to be defined
    }

    [Guid("b63ea76d-1f85-456f-a19c-48159efa858b"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    private interface IShellItemArray
    {
        void _VtblGap1_4(); // skip 4 methods

        int GetCount();
        IShellItem GetItemAt(int dwIndex);
    }

    private enum SIGDN
    {
        SIGDN_NORMALDISPLAY,
        SIGDN_PARENTRELATIVEPARSING,
        SIGDN_DESKTOPABSOLUTEPARSING,
        SIGDN_PARENTRELATIVEEDITING,
        SIGDN_DESKTOPABSOLUTEEDITING,
        SIGDN_FILESYSPATH,
        SIGDN_URL,
        SIGDN_PARENTRELATIVEFORADDRESSBAR,
        SIGDN_PARENTRELATIVE,
        SIGDN_PARENTRELATIVEFORUI
    }

    private enum SVGIO
    {
        SVGIO_BACKGROUND,
        SVGIO_SELECTION,
        SVGIO_ALLVIEW,
        SVGIO_CHECKED,
        SVGIO_TYPE_MASK,
        SVGIO_FLAG_VIEWORDER
    }
}