Get list of selected files from Windows Desktop

问题:

I am trying to get a list of selected files from the Windows Desktop and the Explorer Windows. The requirement is that I should be able to retrieve the current selection from the active explorer window or the Desktop.

I have managed to put together the following code, after going through online resources, but it does not provide a list of selected items from the Desktop.

ArrayList selected = new ArrayList();
var shell = new Shell32.Shell();
IntPtr handle = IntPtr.Zero;
handle = GetForegroundWindow();
int intHandle = handle.ToInt32();

//For each explorer
foreach (InternetExplorer window in new ShellWindowsClass())
{

    if (window.HWND == (int)handle)
    {
        Shell32.FolderItems items = ((Shell32.IShellFolderViewDual2)window.Document).SelectedItems();
        foreach (Shell32.FolderItem item in items)
        {
            selected.Add(item.Path);
        }
    }
}

Other than that, I tried the following but it just gives a list of all selected elements in all open explorer windows while ignoring the Desktop.

string filename; = Path.GetFileNameWithoutExtension(window.FullName).ToLower();
if (filename.ToLowerInvariant() == "explorer")
{
    Shell32.FolderItems items = ((Shell32.IShellFolderViewDual2)window.Document).SelectedItems();
    foreach (Shell32.FolderItem item in items)
    {
        //MessageBox.Show(item.Path.ToString());
        selected.Add(item.Path);
    }
}

So I just always end up with a list from the explorer windows and get no results even when no explorer windows are open. The current techniques seem to be ignoring the Desktop altogether.

I would really appreciate it if someone could help me out to get a list of selected files from the currently active window/desktop.

Thank You.

回答1:

It is easy for desktop since it is still a listview, just find the correct handle. list view is a child of the desktop handle.

Desktop
+- Progman (for backward compatibility)
   +- Shell Def View
      +- SysListView32 (even under 64 bit)

then you can do all listview operations on the list view. but other explorer windows does not contain a list view. Instead they use window with class DirectUIHWND which is a mystery to many. I've just found a post that describes a way to the unravel that mystery.

http://smartbear.com/forums?forumid=81&threadid=68427#68428

I hope it helps.

回答2:

    using System.Runtime.InteropServices;

    public class ShellItems
    {
        [StructLayoutAttribute(LayoutKind.Sequential)]
        private struct LVITEM
        {
            public uint mask;
            public int iItem;
            public int iSubItem;
            public uint state;
            public uint stateMask;
            public IntPtr pszText;
            public int cchTextMax;
            public int iImage;
            public IntPtr lParam;
        }

        const int LVM_FIRST = 0x1000;
        const int LVM_GETSELECTEDCOUNT = 4146;
        const int LVM_GETNEXTITEM = LVM_FIRST + 12;
        const int LVNI_SELECTED = 2;
        const int LVM_GETITEMCOUNT = LVM_FIRST + 4;
        const int LVM_GETITEM = LVM_FIRST + 75;
        const int LVIF_TEXT = 0x0001;

        [DllImport("user32.dll", EntryPoint = "GetShellWindow")]
        public static extern System.IntPtr GetShellWindow();

        [DllImport("user32.dll", SetLastError = true)]
        public static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string className, string windowTitle);

        [DllImport("user32.dll", EntryPoint = "SendMessage", CharSet = CharSet.Auto)]
        public static extern int SendMessagePtr(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam);

        [DllImport("User32.DLL")]
        public static extern int SendMessage(IntPtr hWnd, UInt32 Msg, Int32 wParam, Int32 lParam);


        public int SelectedItemCount
        {
            get
            {
                return SendMessage(ShellListViewHandle, LVM_GETSELECTEDCOUNT, IntPtr.Zero.ToInt32(), IntPtr.Zero.ToInt32());
            }
        }
        public int Count
        {
            get
            {
                return SendMessage(ShellListViewHandle, LVM_GETITEMCOUNT, IntPtr.Zero.ToInt32(), IntPtr.Zero.ToInt32());
            }
        }
        public string GetItemText(int idx)
        {
            // Declare and populate the LVITEM structure
            LVITEM lvi = new LVITEM();
            lvi.mask = LVIF_TEXT;
            lvi.cchTextMax = 512;
            lvi.iItem = idx;            // the zero-based index of the ListView item
            lvi.iSubItem = 0;         // the one-based index of the subitem, or 0 if this
            //  structure refers to an item rather than a subitem
            lvi.pszText = Marshal.AllocHGlobal(512);

            // Send the LVM_GETITEM message to fill the LVITEM structure
            IntPtr ptrLvi = Marshal.AllocHGlobal(Marshal.SizeOf(lvi));
            Marshal.StructureToPtr(lvi, ptrLvi, false);
            try
            {
                SendMessagePtr(ShellListViewHandle, LVM_GETITEM, IntPtr.Zero, ptrLvi);
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine(ex.Message);
            }

            // Extract the text of the specified item
            string itemText = Marshal.PtrToStringAuto(lvi.pszText);
            return itemText;
        }

        IntPtr ShellListViewHandle
        {
            get
            {
                IntPtr _ProgMan = GetShellWindow();
                IntPtr _SHELLDLL_DefViewParent = _ProgMan;
                IntPtr _SHELLDLL_DefView = FindWindowEx(_ProgMan, IntPtr.Zero, "SHELLDLL_DefView", null);
                IntPtr _SysListView32 = FindWindowEx(_SHELLDLL_DefView, IntPtr.Zero, "SysListView32", "FolderView");
                return _SysListView32;
            }
        }

        public int GetSelectedItemIndex(int iPos = -1)
        {
            return SendMessage(ShellListViewHandle, LVM_GETNEXTITEM, iPos, LVNI_SELECTED);
        }
    }

回答3:

I think you should communicate between processes. Following topics will help.

This is an example of retrieving icons from desktop. List of desktop items and their current positions are fetched. http://social.msdn.microsoft.com/Forums/windows/en-US/d7df8a4d-fc0f-4b62-80c9-7768756456e6/how-can-i-get-desktops-icons-information-?forum=winforms

Here the parameter LVM_GETITEMSTATE can be used within the sample code from the link above. http://msdn.microsoft.com/en-us/library/windows/desktop/bb761053(v=vs.85).aspx

Good luck..