c#，保存图像为Icon

/// <summary>/// Icon操作类，实现了将Image图像向Icon的转化/// /// 调用示例：/// Image pic = Image.FromFile(@"D:/tmp/2.png");/// IconTool.SaveToIcon(pic, @"D:/tmp/test2.ico");/// </summary>class IconTool{    /// <summary>    /// Icon图像信息类    /// </summary>    public class IconInfo    {        public byte Width = 16;         // 图像宽度        public byte Height = 16;        // 图像高度        public byte ColorNum = 0;       // 图像中的颜色数        public byte Reserved = 0;       // 保留字        public ushort Planes = 1;       // 为目标设备说明位面数        public ushort PixelBit = 32;    // 每个像素素所占位数        public uint ImageSize = 0;      // 图像字节大小        public uint ImageOffset = 0;    // 图形数据起点偏移位置        public byte[] ImageData;        // 图形数据        /// <summary>        /// 创建默认的Icon图像数据结构        /// </summary>        public IconInfo() { }    }    /// <summary>    /// 从pic创建Icon信息, 生成Icon的尺寸为rect    /// </summary>    public static IconInfo creatIconInfo(Image pic, Rectangle rect)    {        int w = pic.Width > 255 ? 255 : pic.Width;        int h = pic.Height > 255 ? 255 : pic.Height;        if (rect == Rectangle.Empty || rect.Width > 255 || rect.Height > 255) rect = new Rectangle(0, 0, w, h);        // 创建最适尺寸的图像        Bitmap IconBitmap = new Bitmap(rect.Width, rect.Height);        Graphics g = Graphics.FromImage(IconBitmap);        g.DrawImage(pic, rect, new Rectangle(0, 0, pic.Width, pic.Height), GraphicsUnit.Pixel);        g.Dispose();        // 以位图的形式保存到内存流中        System.IO.MemoryStream memoryStream = new System.IO.MemoryStream();        IconBitmap.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Bmp);        // 从位图创建Icon属性        IconInfo iconInfo1 = new IconInfo();        iconInfo1.Width = (byte)rect.Width;        iconInfo1.Height = (byte)rect.Height;        // 获取图形数据        memoryStream.Position = 14;        iconInfo1.ImageData = new byte[memoryStream.Length - memoryStream.Position];        memoryStream.Read(iconInfo1.ImageData, 0, iconInfo1.ImageData.Length);        // Icon图像的高是BMP的2倍        byte[] Height = BitConverter.GetBytes((uint)iconInfo1.Height * 2);        iconInfo1.ImageData[8] = Height[0];        iconInfo1.ImageData[9] = Height[1];        iconInfo1.ImageData[10] = Height[2];        iconInfo1.ImageData[11] = Height[3];        iconInfo1.ImageSize = (uint)iconInfo1.ImageData.Length;        iconInfo1.ImageOffset = 6 + (uint)(1 * 16);        return iconInfo1;    }    /// <summary>    /// 保存pic为Icon图像,保存文件路径名称FileName    /// </summary>    public static void SaveToIcon(Image pic, string FileName)    {        SaveToIcon(pic, Rectangle.Empty, FileName);    }    /// <summary>    /// 保存pic为Icon图像,尺寸rect，保存文件路径名称PathName    /// </summary>    public static void SaveToIcon(Image pic, Rectangle rect, string PathName)    {        // 获取Icon信息        IconInfo iconInfo = creatIconInfo(pic, rect);        // 创建文件输出流，写入文件，生成Icon图像        System.IO.FileStream stream = new System.IO.FileStream(PathName, System.IO.FileMode.Create);        // 写入Icon固定部分        ushort Reserved = 0;        ushort Type = 1;        ushort Count = 1;        byte[] Temp = BitConverter.GetBytes(Reserved);        stream.Write(Temp, 0, Temp.Length);        Temp = BitConverter.GetBytes(Type);        stream.Write(Temp, 0, Temp.Length);        Temp = BitConverter.GetBytes((ushort)Count);        stream.Write(Temp, 0, Temp.Length);        // 写入Icon头信息        stream.WriteByte(iconInfo.Width);        stream.WriteByte(iconInfo.Height);        stream.WriteByte(iconInfo.ColorNum);        stream.WriteByte(iconInfo.Reserved);        Temp = BitConverter.GetBytes(iconInfo.Planes);        stream.Write(Temp, 0, Temp.Length);        Temp = BitConverter.GetBytes(iconInfo.PixelBit);        stream.Write(Temp, 0, Temp.Length);        Temp = BitConverter.GetBytes(iconInfo.ImageSize);        stream.Write(Temp, 0, Temp.Length);        Temp = BitConverter.GetBytes(iconInfo.ImageOffset);        stream.Write(Temp, 0, Temp.Length);        // 写入图形数据        stream.Write(iconInfo.ImageData, 0, iconInfo.ImageData.Length);        stream.Close();    }}