Chris Taylor

Retrieving File Information using SHGetFileInfo

This week a colleque of mine needed to retrieve icons associated with a file. So I put together the following piece of code and figured why not share it.

    struct SHFILEINFO
    {
      public IntPtr hIcon;
      public int    iIcon;
      public int    dwAttributes;
      [MarshalAs(UnmanagedType.ByValTStr, SizeConst=260)]
      public string szDisplayName;
      [MarshalAs(UnmanagedType.ByValTStr, SizeConst=80)]  
      public string szTypeName;
    }
    
    [Flags]
    enum FileInfoFlags : int
    {
      SHGFI_ICON              = 0x000000100,     // get icon
      SHGFI_DISPLAYNAME       = 0x000000200,     // get display name
      SHGFI_TYPENAME          = 0x000000400,     // get type name
      SHGFI_ATTRIBUTES        = 0x000000800,     // get attributes
      SHGFI_ICONLOCATION      = 0x000001000,     // get icon location
      SHGFI_EXETYPE           = 0x000002000,     // return exe type
      SHGFI_SYSICONINDEX      = 0x000004000,     // get system icon index
      SHGFI_LINKOVERLAY       = 0x000008000,     // put a link overlay on icon
      SHGFI_SELECTED          = 0x000010000,     // show icon in selected state
      SHGFI_ATTR_SPECIFIED    = 0x000020000,     // get only specified attributes
      SHGFI_LARGEICON         = 0x000000000,     // get large icon
      SHGFI_SMALLICON         = 0x000000001,     // get small icon
      SHGFI_OPENICON          = 0x000000002,     // get open icon
      SHGFI_SHELLICONSIZE     = 0x000000004,     // get shell size icon
      SHGFI_PIDL              = 0x000000008,     // pszPath is a pidl
      SHGFI_USEFILEATTRIBUTES = 0x000000010,     // use passed dwFileAttribute
      SHGFI_ADDOVERLAYS       = 0x000000020,     // apply the appropriate overlays
      SHGFI_OVERLAYINDEX      = 0x000000040,     // Get the index of the overlay in 
                                                 // the upper 8 bits of the iIcon
    }                                                 
    [DllImport("shell32.dll", CharSet=CharSet.Auto)]
    static extern Int64 SHGetFileInfo(string pszPath, int
      dwFileAttributes, out SHFILEINFO psfi, int cbFileInfo, FileInfoFlags uFlags);

To call this function to retrieve the icon information of  file is now as simple as.

SHFILEINFO fi;
SHGetFileInfo(strFile, 0, out fi, Marshal.SizeOf(typeof(SHFILEINFO)), 
FileInfoFlags.SHGFI_ICON );

Icon.FromHandle(fi.hIcon);