public static extern bool EnumResourceNames(IntPtr hModule, IntPtr lpszType, Enumresnameproc lpEnumFunc,
IntPtr lParam);
private void Initialize(string fileName)
{
if (fileName == null)
{
throw new ArgumentNullException(nameof(fileName));
}
var hModule = IntPtr.Zero;
try
{
hModule = NativeMethods.LoadLibraryEx(fileName, IntPtr.Zero, LOAD_LIBRARY_AS_DATAFILE);
if (hModule == IntPtr.Zero)
{
throw new Win32Exception();
}
FileName = GetFileName(hModule);
// Enumerate the icon resource and build .ico files in memory.
var tmpData = new List <byte[]>();
Enumresnameproc callback = (h, t, name, l) =>
{
// Refer the following URL for the data structures used here:
// http://msdn.microsoft.com/en-us/library/ms997538.aspx
// RT_GROUP_ICON resource consists of a GRPICONDIR and GRPICONDIRENTRY's.
var dir = GetDataFromResource(hModule, _rtGroupIcon, name);
// Calculate the size of an entire .icon file.
int count = BitConverter.ToUInt16(dir, 4); // GRPICONDIR.idCount
var len = 6 + 16 * count; // sizeof(ICONDIR) + sizeof(ICONDIRENTRY) * count
for (var i = 0; i < count; ++i)
{
len += BitConverter.ToInt32(dir, 6 + 14 * i + 8); // GRPICONDIRENTRY.dwBytesInRes
}
using (var dst = new BinaryWriter(new MemoryStream(len)))
{
// Copy GRPICONDIR to ICONDIR.
dst.Write(dir, 0, 6);
var picOffset = 6 + 16 * count; // sizeof(ICONDIR) + sizeof(ICONDIRENTRY) * count
for (var i = 0; i < count; ++i)
{
// Load the picture.
var id = BitConverter.ToUInt16(dir, 6 + 14 * i + 12); // GRPICONDIRENTRY.nID
var pic = GetDataFromResource(hModule, _rtIcon, (IntPtr)id);
// Copy GRPICONDIRENTRY to ICONDIRENTRY.
dst.Seek(6 + 16 * i, SeekOrigin.Begin);
dst.Write(dir, 6 + 14 * i, 8); // First 8bytes are identical.
dst.Write(pic.Length); // ICONDIRENTRY.dwBytesInRes
dst.Write(picOffset); // ICONDIRENTRY.dwImageOffset
// Copy a picture.
dst.Seek(picOffset, SeekOrigin.Begin);
dst.Write(pic, 0, pic.Length);
picOffset += pic.Length;
}
tmpData.Add(((MemoryStream)dst.BaseStream).ToArray());
}
return(true);
};
NativeMethods.EnumResourceNames(hModule, _rtGroupIcon, callback, IntPtr.Zero);
_iconData = tmpData.ToArray();
}
finally
{
if (hModule != IntPtr.Zero)
{
NativeMethods.FreeLibrary(hModule);
}
}
}
public static extern bool EnumResourceNames(IntPtr hModule, IntPtr lpszType, Enumresnameproc lpEnumFunc,
IntPtr lParam);
