you are right. But insted of handling CANbus messages I'm handling LINbus messages. The frames are really known and are specified in a file called LIN description file *.ldf (the format of file is defined in the specification). But how do I create structs from this file at runtime to use it for decoding a message? Or what would be the best approach?
Basically I would be able to define some struct like:
and then assign all 8 bytes to this struct and decode it bit-by-bit. But seems to me to be still clumsy and slow. Or this is just the only one solution.
Maybe the solution is really clear and simple, but I'm missing something.
I read LINbus is the cheaper alternatic to CANbus used by various car manufacturers, so I doubt it would get there without being easy to interface to.
You can design a system, module, program etc if you know what the messages and interactions are: it's inputs and outputs and the behaviour expected. If you don't know such things, you're in trouble: by that design rule anyway. So I'd check, are these messages really as randomly organized as you think? It could be there are only three of four possibilities, not ten or fifty.
Is there someone writing the code to send these messages that doesn't understand the LINbus spec? I was put off by someones CANbus coding when they said 'it's too complicated, you wouldn't understand'. Their code failed, I got a copy of the CANbus spec, read it, understood it, and we produced a great system.
You can't be the first to have done this. Get in touch with manufacturers of the kit you're using to try and het their demo code and base what you're doing on that. Much easier than starting from scratch.
Or try using Unions, pre-define them for the possible message formats then apply the correct one based on the ID.
Whatever you do you have to know the structure of every message. You can either create a load of structures in the code before you compile or you can write code that at run time pulls the data apart, which is more work.
If you really have an idf file that defines the data why not write a program that can read the idf file and produce a header file from it? That is if writing the header file yourself is too much.
The LASTINPUTINFO structure contains the tick count when the last input event occurred. You would use the [^] GetTickCount function[^] function to get current tick count and then subtract the value obtained from LASTINPUTINFO.dwTime to obtain the number of milliseconds since the last input event. This value divided by 1000 would obviously be the number of seconds since the last input event occurred.
I want to write a program in which the main form will transparent to mouse, but the requirement is: when I click on the form, it will turn transparent and let the mouse click through it, but when I drag the mouse, the form will not be transparent so that I can draw on it.
I found many articles teaching how to make a transparent form to mouse by using layered window with ModifyStyleEx and WS_EX_TRANSPARENT bit turned on. But when I press the mouse down, the form looses focus so I cannot catch whenever the mouse is clicked or dragged.
Does anyone have an idea?
Thanks in advance.
Here is a tip, I haven't tried it! Maybe you should play around by handling the WM_NCHITTEST window message in your program. You can return HTTTRANSPARENT or whatever you want, can pass the message handling to the default window proc, whatever you want. Whit this you may manage to handle mouse messages. Making the form opaque/transparent is another task on top of input handling, you can find lots of tutorials on how to do that correctly.
In my project, a batch file should be first started to launch cmd windows, as well as initializing some parameters and some background processes. in the cmd windows,my own calculation processes could be started by typing the exe name directly. Now, i've written a MFC application program, and want to implement my calculaiton processes in a dialog button. I want to use ShellExecute where the first paramter is the cmd window handle i've got. Can anybody tell me how to write the shellexexute to post a command line to an existing cmd windows.
Another option is changing your design to use a master application instead of the batch file that starts all necessary processes where the master application and the processes use some kind of Interprocess Communications[^].
Last Visit: 31-Dec-99 19:00 Last Update: 30-Nov-23 14:13