将图标拆分为Bitmap
部分很容易:
Bitmap icon16 = new Icon(combinedIcon, new Size(16, 16)).ToBitmap()
但是您如何将多个Bitmap
对象合并到一个Icon
中?
Bitmap icon16, icon32, icon64;
Icon combinedIcon = [...]
我对整个Icon
对象不是很清楚。它确实是一组多个图像。加载时,可以将其分成Bitmap
部分。但是我看不到任何创建多图标的方法。无法以明显的方式来迭代,添加或删除Bitmap
部分,例如拥有一组位图,似乎也很奇怪。
答案 0 :(得分:1)
.Net中的Icon
类非常基础,甚至还没有接近访问实际图标格式的所有功能的机会。最好将图标构造为字节流,然后将其加载为图标。
我回想了一下格式,实际上它接受png数据作为内部图像。请注意,这些图像的宽度或高度不能超过256个像素,并且文件中的图像量以两个字节保存,因此它不能超过Int16.MaxValue
或0xFFFF或65535。
代码应如下所示:
public static Icon ConvertImagesToIco(Image[] images)
{
if (images == null)
throw new ArgumentNullException("images");
Int32 imgCount = images.Length;
if (imgCount == 0)
throw new ArgumentException("No images given!", "images");
if (imgCount > 0xFFFF)
throw new ArgumentException("Too many images!", "images");
using (MemoryStream ms = new MemoryStream())
using (BinaryWriter iconWriter = new BinaryWriter(ms))
{
Byte[][] frameBytes = new Byte[imgCount][];
// 0-1 reserved, 0
iconWriter.Write((Int16)0);
// 2-3 image type, 1 = icon, 2 = cursor
iconWriter.Write((Int16)1);
// 4-5 number of images
iconWriter.Write((Int16)imgCount);
Int32 offset = 6 + (16 * imgCount);
for (Int32 i = 0; i < imgCount; ++i)
{
// Get image data
Image curFrame = images[i];
if (curFrame.Width > 256 || curFrame.Height > 256)
throw new ArgumentException("Image too large!", "images");
// for these three, 0 is interpreted as 256,
// so the cast reducing 256 to 0 is no problem.
Byte width = (Byte)curFrame.Width;
Byte height = (Byte)curFrame.Height;
Byte colors = (Byte)curFrame.Palette.Entries.Length;
Int32 bpp;
Byte[] frameData;
using (MemoryStream pngMs = new MemoryStream())
{
curFrame.Save(pngMs, ImageFormat.Png);
frameData = pngMs.ToArray();
}
// Get the colour depth to save in the icon info. This needs to be
// fetched explicitly, since png does not support certain types
// like 16bpp, so it will convert to the nearest valid on save.
Byte colDepth = frameData[24];
Byte colType = frameData[25];
// I think .Net saving only supports 2, 3 and 6 anyway.
switch (colType)
{
case 2: bpp = 3 * colDepth; break; // RGB
case 6: bpp = 4 * colDepth; break; // ARGB
default: bpp = colDepth; break; // Indexed & greyscale
}
frameBytes[i] = frameData;
Int32 imageLen = frameData.Length;
// Write image entry
// 0 image width.
iconWriter.Write(width);
// 1 image height.
iconWriter.Write(height);
// 2 number of colors.
iconWriter.Write(colors);
// 3 reserved
iconWriter.Write((Byte)0);
// 4-5 color planes
iconWriter.Write((Int16)0);
// 6-7 bits per pixel
iconWriter.Write((Int16)bpp);
// 8-11 size of image data
iconWriter.Write(imageLen);
// 12-15 offset of image data
iconWriter.Write(offset);
offset += imageLen;
}
for (Int32 i = 0; i < imgCount; i++)
{
// Write image data
// png data must contain the whole png data file
iconWriter.Write(frameBytes[i]);
}
iconWriter.Flush();
ms.Position = 0;
return new Icon(ms);
}
}
请注意,与其他System.Drawing
图像格式不同,Icon
类不是要求流保持打开状态;它只是从流中读取字节并将其留在那里。