C / C++ / MFC

Re: Help with an unicode String returned by DeviceIoControl

13-Jul-08 9:49

Hello,

i have the following problem (i think it is a beginner question but i hope to get an informative answer!)

Actually i try to get the BatteryDeviceName of my notebook. I use the code snipped from the MSDN.
But at these step iam hanging because the DeviceIoControl returns a BATTERY_INFORMATION structure, because the InformationLevel (bqi) is set to BatteryInformation. BUT I want the BatteryDeviceName, so I changed the Information Level. Then the IOCTL_BATTERY_QUERY_INFORMATION should return a null terminated unicode string.

My question is how can i store this ?string?

Here is my code:

BATTERY_INFORMATION bi = {0};
bqi.InformationLevel = BatteryDeviceName;

if(DeviceIoControl(hBattery,IOCTL_BATTERY_QUERY_INFORMATION,&bqi,sizeof(bqi),&bi,sizeof(bi),&dwOut,NULL))
{
	MessageBox(NULL,L"#8 - IOCTL_BATTERY_QUERY_INFORMATION ... OK",L"",MB_ICONINFORMATION);
	MessageBox(NULL,L"[BatteryDeviceName should be here !!!]",L"",MB_ICONINFORMATION);	
}

As you can see i need to replace the bold line or more to store the String.

I hope someone can help me.

Thanks,
gabbana

Mark Salsbery13-Jul-08 10:08

Re: Help with an unicode String returned by DeviceIoControl

13-Jul-08 10:08

Maybe something like this:

wchar_t szBatteryDeviceName[260];
bqi.InformationLevel = BatteryDeviceName;

if(DeviceIoControl(hBattery,IOCTL_BATTERY_QUERY_INFORMATION,&bqi,sizeof(bqi),szBatteryDeviceName,sizeof(szBatteryDeviceName),&dwOut,NULL))
{
   ...
}

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

gabbana13-Jul-08 10:16

Re: Help with an unicode String returned by DeviceIoControl

13-Jul-08 10:16

Great thank you, but i have one problem:

If I use the szBatteryDeviceName in the MessageBox, he prints the correct batterydevicename but adds a part of the application path, so i think it ignores the null terminated string ?

Mark Salsbery13-Jul-08 13:40

Re: Help with an unicode String returned by DeviceIoControl

13-Jul-08 13:40

Interesting - I wouldn't expect that.

I guess you could add the null terminator yourself:

wchar_t szBatteryDeviceName[260];
bqi.InformationLevel = BatteryDeviceName;

if(DeviceIoControl(hBattery,IOCTL_BATTERY_QUERY_INFORMATION,&bqi,sizeof(bqi),szBatteryDeviceName,sizeof(szBatteryDeviceName),&dwOut,NULL))
{
   szBatteryDeviceName[dwOut/sizeof(wchar_t)] = 0;
   ...
}

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

gabbana13-Jul-08 23:01

Re: Help with an unicode String returned by DeviceIoControl

13-Jul-08 23:01

Ahh now it works fine.

Great help, thanks!

bye,
gabbana

gabbana13-Jul-08 23:22

Re: Help with an unicode String returned by DeviceIoControl

13-Jul-08 23:22

Okay,
now i tried this with another type. I only get -1 as seconds, i am not sure if this is for a constant that the estimatedtime value is not available, but is the way correct for getting them:

estimated time should return as an ULONG.

ULONG estimatedtime;
bqi.InformationLevel = BatteryEstimatedTime;
DeviceIoControl(hBattery,IOCTL_BATTERY_QUERY_INFORMATION,&bqi,sizeof(bqi),&estimatedtime,sizeof(ULONG),&dwOut,NULL);
wchar_t szestimatedtime[260];
wsprintf(szestimatedtime,L"%d seconds",estimatedtime);
MessageBox(NULL,szestimatedtime,L"",0);

Thanks for help!

bye,
gabbana

Mark Salsbery14-Jul-08 5:30

Re: Help with an unicode String returned by DeviceIoControl

14-Jul-08 5:30

gabbana wrote:
I only get -1 as seconds

-1 == 0xFFFFFFFF == BATTERY_UNKNOWN_TIME (BatClass.h)

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

David Crow14-Jul-08 8:27

David Crow

14-Jul-08 8:27

From MSDN, if the estimated time is unknown (for example, the battery is not discharging and the AtRate specified was 0) this will return BATTERY_UNKNOWN_TIME.

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

How can I capture in Windows Mobile 5/6 keys like Message/Explorer/Windows

Tili13-Jul-08 9:25

Tili

13-Jul-08 9:25

How can I capture the default keys on a windows mobile phone that open messaging, internet explorer and even start button.

I want to be able to capture those and then disallow windows itself to open messaging application.

I know this is bad to do but I have to make an app to lock phone and I cannot allow any other application to be run by user.

Thanks in advance

-----------------------------
In my dream, I was dorwning my §orrow§
But my §orrow§, they learned to §wim

How to make width of arrows at the right of CComboBox and CMFCColorButton the same?

followait13-Jul-08 2:54

followait

13-Jul-08 2:54

Both are aready in XP style.

BTW, I don't understand why M$ make them differenct in width. Sniff | :^)

system

Re: How to make width of arrows at the right of CComboBox and CMFCColorButton the same?

Mark Salsbery13-Jul-08 10:15

can not set breakpoint in release mode

13-Jul-08 10:15

CComboBox wraps the Windows combo box control.

CMFCColorButton is a control implemented in a library.
Why the author(s) chose not to use the system width metric, I don't know.
CMFCColorButton was not written by Microsoft AFAIK.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

George_George13-Jul-08 0:31

13-Jul-08 0:31

Hello everyone,

For the following code, I can not set breakpoint in release mode, but the same command in WinDbg works fine in debug mode. Anything wrong?

Here is my Windbg command and output in release mode and source codes. I have tested in release mode breakpoint at foo does not take effect, but in debug mode it takes effect.

0:000> bp foo
Bp expression 'foo' could not be resolved, adding deferred bp
0:000> bp main
0:000> bl
 0 eu                      0001 (0001) (foo)
 1 e 00000001`40001000     0001 (0001)  0:**** Test64bitDebug!main

int foo (int a, int b)
{
 return a+b;
}
int main()
{
 int a1 = 100;
 int b1 = a1 + 100;
 a1 = foo (a1, b1);
 return 0;
}

thanks in advance,
George

Ștefan-Mihai MOGA13-Jul-08 0:56

13-Jul-08 0:56

Hi George,

could you please tell us why you need breakpoints for release mode applications? You also have the debug mode to debug your application. Don't you think is enought?

Best regards,
Mihai Moga

George_George13-Jul-08 2:01

13-Jul-08 2:01

Thanks Mihai,

Because in real test environment, we need to work with release mode code, not debug mode code. Anyway, any ideas to my original question?

regards,
George

Ștefan-Mihai MOGA13-Jul-08 4:17

13-Jul-08 4:17

Hi George,

I do not have an answer to your original question, but did you read Keith Rule's Debugging Release Mode Problems[^] article?

Best regards,
Mihai Moga

George_George14-Jul-08 22:19

14-Jul-08 22:19

Thanks Mihai,

I read through the article, looks great! A few more comments,

1. We could only use VERIFY in MFC based application, corrrect?

2. In the article it is mentioned "In my personal experience, I've rarely seen a problem that really was bad code generation. My experience with VC++ 6.0 has been that the compiler occasionally asserts while generating code (especially when using templates), but I've not experienced any problem with my code associated with bad code generation. Installing service release 3 seems to have taken care of all the code generation asserts that I've seen in previous versions."

What means "asserts" here?

regards,
George

Ștefan-Mihai MOGA15-Jul-08 9:12

15-Jul-08 9:12

Hi George,

to answer to your questions I gently ask you to read couple more articles:
a) Rob Manderson's Assert is your friend[^]
b) srana's MFC Windows Coding Guidelines[^]

Best regards,
Mihai Moga

P.S. YES, you should use only

VERIFY

to ensure that your code goes to release version of your application; use

ASSERT

only for definitions/expressions/assertions.

George_George16-Jul-08 19:11

16-Jul-08 19:11

Thanks Mihai,

I have read through the article. And I want to confirm with you that VERIFY could only be used with MFC application, correct?

regards,
George

Ștefan-Mihai MOGA17-Jul-08 8:30

17-Jul-08 8:30

Yes George, you are right.

Best regards,
Mihai Moga

George_George17-Jul-08 21:01

17-Jul-08 21:01

Great, thanks Mihai!

Any comments to my question item 2 here?

http://www.codeproject.com/script/Forums/View.aspx?fid=1647&msg=2638078[^]

regards,
George

Stephen Hewitt13-Jul-08 15:11

Stephen Hewitt

13-Jul-08 15:11

It's not enough. Although you should debug in the debug build most times there are classes of bugs that only manifest in release builds.

Steve

George_George13-Jul-08 19:47

13-Jul-08 19:47

Thanks Steve,

Any comments to my original question? Smile | :)

regards,
George