myBitmap.RawFormat与任何已知的ImageFormat有什么不同？

Question

我正在使用GDI +,我创建了一个像这样的新位图:

var bmp = new Bitmap(width, height);

现在,当我观察它的RawFormat.Guid时,我发现它与所有预定义的ImageFormats不同(我希望它是JPEG).

ImageFormat.Jpeg.Guid
    {b96b3cae-0728-11d3-9d7b-0000f81ef32e}
format.Guid
    {b96b3caa-0728-11d3-9d7b-0000f81ef32e}

有趣的是,你可以看到它们是相同的,除了一个让我更加困惑的角色.

知道为什么吗？哪些代码部分决定了我创建的位图的RawFormat是什么？我们如何确保它是有效的ImageFormat？

谢谢.

Answer 1

从Windows SDK,<gdiplusimaging.h>头文件:

DEFINE_GUID(ImageFormatUndefined, 0xb96b3ca9,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);
DEFINE_GUID(ImageFormatMemoryBMP, 0xb96b3caa,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);
DEFINE_GUID(ImageFormatBMP, 0xb96b3cab,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);
DEFINE_GUID(ImageFormatEMF, 0xb96b3cac,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);
DEFINE_GUID(ImageFormatWMF, 0xb96b3cad,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);
DEFINE_GUID(ImageFormatJPEG, 0xb96b3cae,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);
DEFINE_GUID(ImageFormatPNG, 0xb96b3caf,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);
DEFINE_GUID(ImageFormatGIF, 0xb96b3cb0,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);
DEFINE_GUID(ImageFormatTIFF, 0xb96b3cb1,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);
DEFINE_GUID(ImageFormatEXIF, 0xb96b3cb2,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);
DEFINE_GUID(ImageFormatIcon, 0xb96b3cb5,0x0728,0x11d3,0x9d,0x7b,0x00,0x00,0xf8,0x1e,0xf3,0x2e);

"记忆BMP",非常合适.是的,微软经常会手动使用GUID.淘气.