I began to use QNX just one month ago,now I want to use photon to build my MMI,but I don’t know how to use the API function,the example in mannul is too simple,if you have the book or example about using photon,please send to me,thank you very much! my email is 
uyong@epri.ac.cn
MMI? Can you give more details about what you want to do? I have been able to learn how to do everything I have ever needed from docs (even before I worked @ QNX).
MMI or HMI is short for Man-Machine Interface, an Industrial Automation acronym.
Photon Application Builder (PhAB) is the program you want to build with. This is installed as part of the standard install.
There is also a number of offerings from specialists in this field, eg, the TILCON Real-Time Developer from tilcon.com/products.html
I work in the field of satellite communications and I wrote a MMI (easy one) using photon.
I have started with some buttons and labels and using the reference manual it is not hard to use new and more complicated widgets.
Of course, using Photon Application Builder.
If you prefer pdf, take a look to:
mech.nwu.edu/courses/433/QNX/ReferenceDocs/
The manuals are in pdf format (I prefer pdf to learn a new thing)
Take a look too, to the technical articles about photon in www.qnx.com.
It can help you too.