public byte[] GenerateIconFile()
{
int[] sizes = this.bitmaps.Keys.OrderBy(i => i).ToArray();
if (sizes.Length == 0)
{
throw new InvalidOperationException("Cannot generate empty icon file.");
}
List <byte> imageBytes = new List <byte>();
List <int> startingPositions = new List <int>();
int startingPosition = 6 + 16 * sizes.Length; // ico header is 6 bytes and each file header is 16 bytes.
List <byte> icoHeader = new List <byte>();
List <byte> pngHeaders = new List <byte>();
List <byte> pngPayloads = new List <byte>();
ToLittleEndian(0, 2, icoHeader); // first two bytes are always 0
ToLittleEndian(1, 2, icoHeader); // 1 for ICO format (2 is CUR)
ToLittleEndian(sizes.Length, 2, icoHeader); // number of files
foreach (int size in sizes)
{
UniversalBitmap originalImage = this.bitmaps[size];
int width = originalImage.Width;
int height = originalImage.Height;
int x = (size - width) / 2;
int y = (size - height) / 2;
UniversalBitmap resource = new UniversalBitmap(size, size);
UniversalBitmap.DrawingSession g = resource.CreateNewDrawingSession();
g.Blit(originalImage, x, y);
g.Flush();
byte[] pngBytes = resource.GetBytesAsPng();
pngPayloads.AddRange(pngBytes);
ToLittleEndian(size == 256 ? 0 : size, 1, pngHeaders);
ToLittleEndian(size == 256 ? 0 : size, 1, pngHeaders);
ToLittleEndian(0, 1, pngHeaders); // 0 for not using a color palette
ToLittleEndian(0, 1, pngHeaders); // reserved, always 0
ToLittleEndian(0, 2, pngHeaders); // 0 color planes.
ToLittleEndian(32, 2, pngHeaders); // 32 bits per pixel
ToLittleEndian(pngBytes.Length, 4, pngHeaders); // file size in bytes
ToLittleEndian(startingPosition, 4, pngHeaders); // byte position from the beginning of the file
startingPosition += pngBytes.Length;
}
List <byte> finalOutput = icoHeader;
finalOutput.AddRange(pngHeaders);
finalOutput.AddRange(pngPayloads);
return(finalOutput.ToArray());
}
