public unsafe void Save(MultiIcon multiIcon, Stream stream)
{
// LoadLibraryEx only can load files from File System, lets create a tmp file
string tmpFile = null;
IntPtr hLib = IntPtr.Zero;
MemoryStream ms;
bool bResult;
try
{
stream.Position = 0;
// Find a tmp file where to dump the DLL stream, later we will remove this file
tmpFile = Path.GetTempFileName();
FileStream fs = new FileStream(tmpFile, FileMode.Create, FileAccess.Write);
byte[] buffer = Resource.EmptyDll;
stream.Read(buffer, 0, buffer.Length);
fs.Write(buffer, 0, buffer.Length);
fs.Close();
// Begin the injection process
IntPtr updPtr = Win32.BeginUpdateResource(tmpFile, false);
if (updPtr == IntPtr.Zero)
{
throw new InvalidFileException();
}
ushort iconIndex = 1;
foreach (SingleIcon singleIcon in multiIcon)
{
// Lets scan all groups
GRPICONDIR grpIconDir = GRPICONDIR.Initalizated;
grpIconDir.idCount = (ushort)singleIcon.Count;
grpIconDir.idEntries = new GRPICONDIRENTRY[grpIconDir.idCount];
for (int i = 0; i < singleIcon.Count; i++)
{
// Inside every Icon let update every image format
IconImage iconImage = singleIcon[i];
grpIconDir.idEntries[i] = iconImage.GRPICONDIRENTRY;
grpIconDir.idEntries[i].nID = iconIndex;
// Buffer creation with the same size of the icon to optimize write call
ms = new MemoryStream((int)grpIconDir.idEntries[i].dwBytesInRes);
iconImage.Write(ms);
buffer = ms.GetBuffer();
// Update resource but it doesn't write to disk yet
bResult = Win32.UpdateResource(updPtr, (int)ResourceType.RT_ICON, iconIndex, 0, buffer, (uint)ms.Length);
iconIndex++;
// For some reason Windows will fail if there are many calls to update resource and no call to endUpdateResource
// It is like there some internal buffer that gets full, after that all calls fail.
// This workaround will save the changes every 70 icons, for big files this slow the saving process significantly
// but I didn't find a way to make EndUpdateResource works without save frequently
if ((iconIndex % 70) == 0)
{
bResult = Win32.EndUpdateResource(updPtr, false);
updPtr = Win32.BeginUpdateResource(tmpFile, false);
if (updPtr == IntPtr.Zero)
{
throw new InvalidFileException();
}
}
}
// Buffer creation with the same size of the group to optimize write call
ms = new MemoryStream(grpIconDir.GroupDirSize);
grpIconDir.Write(ms);
buffer = ms.GetBuffer();
int id;
if (int.TryParse(singleIcon.Name, out id))
{
// Write id as an integer
bResult = Win32.UpdateResource(updPtr, (int)ResourceType.RT_GROUP_ICON, (IntPtr)id, 0, buffer, (uint)ms.Length);
}
else
{
// Write id as string
IntPtr pName = Marshal.StringToHGlobalAnsi(singleIcon.Name.ToUpper());
bResult = Win32.UpdateResource(updPtr, (int)ResourceType.RT_GROUP_ICON, pName, 0, buffer, (uint)ms.Length);
Marshal.FreeHGlobal(pName);
}
}
// Last call to update the file with the rest not that was not write before
bResult = Win32.EndUpdateResource(updPtr, false);
// Because Windows Resource functions requiere a filepath, and we need to return an string then lets open
// the temporary file and dump it to the stream received as parameter.
fs = new FileStream(tmpFile, FileMode.Open, FileAccess.Read);
buffer = new byte[fs.Length];
fs.Read(buffer, 0, buffer.Length);
stream.Write(buffer, 0, buffer.Length);
fs.Close();
}
catch (Exception)
{
throw new InvalidFileException();
}
finally
{
if (hLib != null)
{
Win32.FreeLibrary(hLib);
}
if (tmpFile != null)
{
File.Delete(tmpFile);
}
}
}
