Undefined method all_input_usages using libusb

问题:

I wrote this little demo code with libusb:

require 'libusb'

usb = LIBUSB::Context.new
device = usb.devices(:idVendor => 2362).first
puts device.all_input_usages

But somehow I don't get the error:

 undefined method `all_input_usages' for #<LIBUSB::Device:0x2091fa8>

What did I do wrong?

回答1:

You should step away from that demo code, because it is hopelessly outdated and the API has radically changed since.

You can see all available methods in IRB when you type device.methods - Object.new.methods, it's a trick i often use when i want to explore what an object has to offer. Maybe this will help you find the method you are looking for.

回答2:

I guess that the idVendor should be written in hexadecimal spelling, so maybe device = usb.devices(:idVendor => 0x2362).first will work.