Question

In a previous question, there was an explanation how to hide desktop items:

How to hide desktop icons programatically?

For some reason, this code doesn’t work for me.

I would have simply commented on the above link, but I don’t have enough privileges to comment on other people’s questions…

Any ideas what’s going wrong? The desktop simply doesn’t hide.

UPDATE: Additionally, I tried using the following code (as was suggested here), but still no effect:

struct SHELLSTATE
{
      bool fShowAllObjects;
      bool fShowExtensions;
      bool fNoConfirmRecycle;
      bool fShowSysFiles;
      bool fShowCompColor;
      bool fDoubleClickInWebView;
      bool fDesktopHTML;
      bool fWin95Classic;
      bool fDontPrettyPath;
      bool fShowAttribCol;
      bool fMapNetDrvBtn;
      bool fShowInfoTip1;
      bool fHideIcons1;
      bool fWebView1;
      bool fFilter1;
      bool fShowSuperHidden1;
      bool fNoNetCrawling1;
      UInt32 dwWin95Unused;
      uint uWin95Unused;
      long lParamSort;
      int   iSortDirection;
      uint version;
      uint uNotUsed;
      bool fSepProcess;
      bool fStartPanelOn;
      bool fShowStartPage;
      bool fAutoCheckSelect;
      bool fIconsOnly;
      bool fShowTypeOverlay;
      uint fSpareFlags;
}

class MyClass
{
    const UInt32 SSF_HIDEICONS = 0x00004000;

    [DllImport("Shell32.dll")]
    static extern void SHGetSetSettings(ref SHELLSTATE state, UInt32 dwMask, bool bSet);
    static void Foobar()
    {
        SHELLSTATE stateOfMind = new SHELLSTATE();
        Console.WriteLine("Set to true:");
        SHGetSetSettings(ref stateOfMind, SSF_HIDEICONS, true);
        Console.ReadKey();
        Console.WriteLine("Set to false:");
        SHGetSetSettings(ref stateOfMind, SSF_HIDEICONAS, false);
        Console.ReadKey();
    }
}

Answer 1

Here is sample code in C# that will toggle desktop icons.

[DllImport("user32.dll", SetLastError = true)] static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll", SetLastError = true)] static extern IntPtr GetWindow(IntPtr hWnd, GetWindow_Cmd uCmd);
enum GetWindow_Cmd : uint
{
    GW_HWNDFIRST = 0,
    GW_HWNDLAST = 1,
    GW_HWNDNEXT = 2,
    GW_HWNDPREV = 3,
    GW_OWNER = 4,
    GW_CHILD = 5,
    GW_ENABLEDPOPUP = 6
}
[DllImport("user32.dll", CharSet = CharSet.Auto)] static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);

private const int WM_COMMAND = 0x111;

static void ToggleDesktopIcons()
{
    var toggleDesktopCommand = new IntPtr(0x7402);
    IntPtr hWnd = GetWindow(FindWindow("Progman", "Program Manager"), GetWindow_Cmd.GW_CHILD);
    SendMessage(hWnd, WM_COMMAND, toggleDesktopCommand, IntPtr.Zero);
}

This sends a message to the SHELLDLL_DefView child window of Progman, which tells it to toggle visibility (by adding or removing the WS_VISIBLE style) of it’s only child, “FolderView”. “FolderView” is the actual window that contains the icons.

To test to see if icons are visible or not, you can query for the WS_VISIBLE style by using the GetWindowInfo function, shown below:

[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("user32.dll", SetLastError = true)]
private static extern bool GetWindowInfo(IntPtr hwnd, ref WINDOWINFO pwi);

[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
    private int _Left;
    private int _Top;
    private int _Right;
    private int _Bottom;
}

[StructLayout(LayoutKind.Sequential)]
struct WINDOWINFO
{
    public uint cbSize;
    public RECT rcWindow;
    public RECT rcClient;
    public uint dwStyle;
    public uint dwExStyle;
    public uint dwWindowStatus;
    public uint cxWindowBorders;
    public uint cyWindowBorders;
    public ushort atomWindowType;
    public ushort wCreatorVersion;

    public WINDOWINFO(Boolean? filler)
        : this()   // Allows automatic initialization of "cbSize" with "new WINDOWINFO(null/true/false)".
    {
        cbSize = (UInt32)(Marshal.SizeOf(typeof(WINDOWINFO)));
    }

}

Here is a function that calls the above code and returns true if the window is visible, false if not.

static bool IsVisible()
{
    IntPtr hWnd = GetWindow(GetWindow(FindWindow("Progman", "Program Manager"), GetWindow_Cmd.GW_CHILD), GetWindow_Cmd.GW_CHILD);
    WINDOWINFO info = new WINDOWINFO();
    info.cbSize = (uint)Marshal.SizeOf(info);
    GetWindowInfo(hWnd, ref info);
    return (info.dwStyle & 0x10000000) == 0x10000000;
}

The windows API code along with more information about the window styles can be found here: http://www.pinvoke.net/default.aspx/user32/GetWindowInfo.html