如何使用Win32检测彩色打印机？

Question

I have two black-and-white printers, two color printers, and some virtual printers (Fax, CutePDF Writer, etc).

According to the DC_COLORDEVICE query to DeviceCapabilities , only the Fax virtual printer is black-and-white.

According to PLANES and BITSPIXEL queries to GetDeviceCaps , all of the printers have one plane, and only Fax and CutePDF have 1 bit/pixel (are black-and-white).

According to the NUMCOLORS query to GetDeviceCaps , only Fax is black-and-white.

I'm not excited about querying the driver directly , so I haven't tried it yet.

How do I accurately detect a color printer with Win32?

Answer 1

Bummer that DC_COLORDEVICE doesn't give the right answer. The rest of your findings don't surprise me.

You could try creating an information context for the printer with CreateIC , and then use GetDeviceCaps to check the COLORRES property.

(An information context is like a device context that you can query but can't actually draw to. It's useful when you want to know what a printer driver is going to do without actually creating a real device context, which may require the printer being online.)

Checking the number of planes is useless, since everything (to a good approximation) uses a single plane. The number of bits per pixel doesn't actually tell you if those pixels can be color or just grayscale (or just palette entries).

Another idea is to look at the dmColor field in the default DEVMODE for the device.

I had to solve the same problem many, many years ago (before DeviceCapabilities), but I don't remember how I did it.