C / C++ / MFC

20-Nov-07 5:09

Hello everyone,

I am using Visual Studio 2005. I am confused when creating a new smart device project. We can select Windows CE 5.0 or Pocket PC 2003.

My question is, are they compatible? (I am developing native unmanaged C++ application)

1. If I build Windows CE 5.0 project, could it run on Pocket PC 2003 device or emulator?

2. If I build Pocket PC 2003 project, could it run on Windows CE 5.0 device or emulator?

3. What are the differences?

thanks in advance,
George

Matthew Faithfull20-Nov-07 5:23

Matthew Faithfull

20-Nov-07 5:23

Possible differences are in what drivers/hardware are available, memory layout and size, available screen resolutions, available subset of APIs and runtime library calls that are supported. As long as you're not doing any comms or anything close to the hardware or using any obscure APIs or library functions you should be able to write code portable between the two emulators at least. Any real world app is likely to have modules dependent on device hardware, in which case the emulators won't help you anyway. Remember CE 5.0 is really an OS toolkit rather than an OS. Each device type out there has its own build of CE 5.0 which is actually a subtly different OS. Platforms like Pocket PC 2003 are an attempt to standardise some of this variation so that software can run on multiple devices provided the actual CPU is compatible ( ARM V4I is pretty common so a good one to target ).

Nothing is exactly what it seems but everything with seems can be unpicked.

George_George20-Nov-07 15:40

20-Nov-07 15:40

Thanks Matthew,

Great reply! I want to learn more details in your below comments, e.g. what are the obscure APIs do you mean? Is there a list or some official documents?

Matthew Faithfull wrote:
Possible differences are in what drivers/hardware are available, memory layout and size, available screen resolutions, available subset of APIs and runtime library calls that are supported.

Matthew Faithfull wrote:
obscure APIs or library functions

I only use C/C++ standard libraries to access File system, process information and using multiple thread as well. There is also a very simple GUI interface based on Win API. I am wondering in my case, whether it is ok to,

1. make a ARM build on Pocket PC 2003 platform and make the built binary run on Windows CE ARM emulator?
2. make a ARM build on Windows CE platform and make built binary run on Pocket PC 2003 ARM emulator?

regards,
George

Matthew Faithfull20-Nov-07 21:58

Matthew Faithfull

20-Nov-07 21:58

To find out which API calls aren't supported you'll need to look at the documentation for a specific API to see if CE supports it at all and for the Pocket PC 2003 platform to see if its included. It basically depends on which modules the platform includes in its CE build.
A GDI based GUI should be no problem and provided you can handle landscape & portrait screens, low res, different colour depths and adjusting your layout it should run on loads of devices and certainly on both the emulators.
The C/C++ standard libraries are cut down for CE but should be standard across the sample Win CE build and Pocket PC 2003. As long as you remember that thread management and priorities work differently on CE from ordinary Windows you should have no problem. Smile | :)

Nothing is exactly what it seems but everything with seems can be unpicked.

George_George22-Nov-07 19:57

22-Nov-07 19:57

Good advice, thanks Matthew!

have a good weekend,
George

string v.s. basic_string

George_George20-Nov-07 4:55

20-Nov-07 4:55

Hello everyone,

I would like to learn some experiences about when should we use std::basic_string and when should we use std::string?

I learned some Hello World level samples and now want to listen to your practical experiences. Smile | :)

thanks in advance,
George

jhwurmbach20-Nov-07 5:10

jhwurmbach

20-Nov-07 5:10

std::string is a concrete instantiation of std::basic_string with char*. That is std::strings consist of signed 8 bit values.
std::wstring is a concrete instantiation of std::basic_string with wchar_t*. That is std::wstrings consist of unsigned 16 bit values.

You never use std::basic_string_string directly.
When you do not need 16 bit chars, you use std::string.
You may create your own instantiation of std::basic_string with a unsigned char* as underlying type.

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George_George20-Nov-07 15:43

20-Nov-07 15:43

Great reply, thanks jhwurmbach!

regards,
George

Maximilien20-Nov-07 5:18

Maximilien

20-Nov-07 5:18

for normal string operations, you only need to work with std::string.

(inspired from Scott meyers's More Effective C++ )
std::string is a typedef of std::basic_string, something like std::basic_string<char> (and/or support for unicode? with std::wstring ).

If you want to specify what is stored in the std::basic_string and how it is allocated, then you will need to explicitly use std::basic_string and learn to use char_traits and Allocator to tell the string what is in it and how to allocated the memory for it.

Maximilien Lincourt
Your Head A Splode - Strong Bad

George_George20-Nov-07 15:48

20-Nov-07 15:48

Great reply, thanks Maximilien!

regards,
George

Invalid file path error

masnu20-Nov-07 3:38

masnu

20-Nov-07 3:38

I have made all the necessary registry entries to associate my app with a project file that it creates. When I double click on the file my app starts up but I get an invalid path error when opening the file. Once the application is running, however, I can open the project file without any problems. I am getting the file name from the m_lpCmdLine variable in my CWinApp derived class.

Does anyone have any suggestions how to resolve this problem?

Thanks.

David Crow20-Nov-07 3:48

David Crow

20-Nov-07 3:48

masnu wrote:
...but I get an invalid path error when opening the file.

Does the path contain spaces?

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toxcct20-Nov-07 3:50

toxcct

20-Nov-07 3:50

why don't you use your debugger for this ?
you could check where something is lost.

what i suspect is that you have spaces in your file path, and passing it through the commandline will not work since you don't put the path within quotes ("").

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CPallini20-Nov-07 3:55

CPallini

20-Nov-07 3:55

masnu wrote:
Does anyone have any suggestions how to resolve this problem?

Yes, some kinda of debugging: for instance printout (maybe with a message box) command line content.
Smile | :)

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