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Hello all,
This is my first post to this forum, so apologies in advance for the lack of clarity.
Im trying to assign an unsigned 16 bit word to a char array i.e. two 8 bit single bytes.
my value (u16 sum) contains the word value 24fa which I need to insert into the middle of a char array buff[100]. Obviously, I am concious of the fact that the array is of type char (8 bit), thus any allocation will shorten the original value e.g. buff[0] = sum //buff[0] only contains 0x24
Is there any way to change the word value to two 8 bit singular bytes for storage?
Or is there another way via strcat/memcpy etc..etc
Many thanks in advance.
Stu
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oh me too .I can not know use this forum
my english is poor
haha
I
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fisheryj wrote:
haha
So you find it funny if your english is poor?
-prakash
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simonpearson wrote:
Is there any way to change the word value to two 8 bit singular bytes for storage
BYTE b1 = value & 0xff;
BYTE b2 = (value >> 8);
or
WORD *pw = &value;
BYTE *pb = (BYTE *)pw;
// now, pb[0] is the first byte of your WORD and pb[1] is the second
etc..
Cleek | Image Toolkits | Thumbnail maker
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You can use a union. This union can be used to extract the individual bytes of most of the primitive data types. You can add more types as needed.
typedef union
{
double Double;
float Float;
UINT Int;
USHORT Short;
UCHAR Bytes[sizeof(double)];
} UnionBytes;
UnionBytes ub;
ub.Short = your_short;
your_string[x] = wb.Bytes[0];
your_string[x+1] = wb.Bytes[1];
I know you didn't ask this but you can do something similar to access the bits of a byte :
typedef union
{
UCHAR Byte;
struct
{
unsigned Bit0 : 1;
unsigned Bit1 : 1;
unsigned Bit2 : 1;
unsigned Bit3 : 1;
unsigned Bit4 : 1;
unsigned Bit5 : 1;
unsigned Bit6 : 1;
unsigned Bit7 : 1;
} Bits;
} ByteBits
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Hi
I have a very big problem, if you know the answer please please help me.
I have a .Xls file that it has just one column data ( in the type of float). I have to read these data from Xls file and put them on an Array to use in my program, and after some working, I have to write them to an Xls file(different from the first one). It should be as a function().
I`ll really appreciate for your quick replies.
This is my email: z_eftekhari@yahoo.com
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Em, try type some key word of your problem on google.
Possiblely you'll find your answer.
that's what i do most of the time.
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The following VB code is FYI, you must change it to VC
////////////////////////////////////////////////////////////////
Public Function SheetToArray(strFilename As String, intSheetIndex As Integer, intRows As Integer, intColums As Integer, strArray() As String) As Boolean
'Declare objects
Dim excapp As Excel.Application
Dim excbook As Excel.Workbook
Dim excsheet As Excel.Worksheet
ReDim strArray(1 To intRows, 1 To intColums)
Dim intLoopR As Integer
Dim intLoopC As Integer
'Create objects
Set excapp = CreateObject("Excel.application")
Set excbook = excapp.Workbooks.Open(strFilename)
Set excsheet = excbook.Worksheets(intSheetIndex)
'Read the table and fill the array
For intLoopR = 1 To intRows
For intLoopC = 1 To intColums
strArray(intLoopR, intLoopC) = excsheet.Cells(intLoopR, intLoopC)
'excsheet.Range(excsheet.Cells(1, 1), excsheet.Cells(5, 5)).Select
Next intLoopC
Next intLoopR
'Close Excel
excbook.Close
excapp.Quit
'Clear the objects
Set excapp = Nothing
Set excbook = Nothing
Set excsheet = Nothing
SheetToArray = True
Exit Function
End Function
Lane
China
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I know of two ways. The first is to use Excel's ODBC driver. The second is to use Excel Automation. In my opinion, the ODBC method would be easier for what you are doing.
"One must learn from the bite of the fire to leave it alone." - Native American Proverb
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In my Vc++ dialog application , i need to launch the device manager . Is Createprocess the proper way to launch it or is there an alternative ?
Engineering is the effort !
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you are trying to start a control panel applet i.e. a .cpl file.
I do not know (forgot) how to launch a .cpl file but you should find few expamples here or on the net on how to launch any .cpl file.
you can google it as Here[^]
-prakash
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Why not use
rundll32.exe devmgr.dll DeviceManager_Execute
with CreateProcess()?
"One must learn from the bite of the fire to leave it alone." - Native American Proverb
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hi, all
I kinda fixed the issue but still not sure what's wrong with the previous method.
it was having access violation at this point:
void CSurchrgDlg::Exit()
{
if( !m_bCanceled )
{
.....
}
CDialog::OnCancel();
}
now I used "PostMessage( cDlg->GetSafeHwnd(), WM_QUIT, 0, 0 );" replaced the exit funtion at the end of RUN. seems to work.
OR I used PostMessage(WM_QUIT); to replace CDialog::OnCancel(); would work, too.
could someone tell me what's wrong with the calling the CDialog::OnCancel();? Thank you for your time!
-- modified at 17:59 Monday 3rd October, 2005
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If you are multithreading you cant call thouse funtions from another thread.
I dont know if I guessed it rite.
-prakash
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Hi for all
I would like to know what is these types of variables
HDC, HWND, HGLRC.
Thanks a lot
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They are all handles.
"One must learn from the bite of the fire to leave it alone." - Native American Proverb
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what is the different between them?
I
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HDC - Device handle to Device Context.
HWND - Handle to window.
HGLRC - I dont remember (need to lookup)
Basically they are all handles, i.e. The handles are just a 32bit value and nothing more then that.
It is one of the way of hinding the data that the window is using for displaying the window and the user can work on it only by passing the handle to appropriate windows function.
-prakash
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is HGLRC an OpenGL rendering context ?
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yes 
-prakash
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when I try to use this optimization (Visual Studio .NET 2003) I get the following compiler error:
error C2664: '_beginthread' : cannot convert parameter 1 from 'void (void *)' to 'void (__cdecl *)(void *)'
any workarround to avoid this or any other way of use threads and __fastcall optimizations. I need to kill the thread from the class where is created when this class is clossing.
regards.
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So what does the call to _beginthread() look like?
"One must learn from the bite of the fire to leave it alone." - Native American Proverb
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*** Disclaimer: i might not fully understand what you're trying to do ***
_beginthread() takes the address of a function meant to be called using the __cdecl calling convention. If you want to start a thread using _beginthread(), you will create a __cdecl function (just put __cdecl before the function name) and pass the address in. End of story.
Mostly OT, but keep in mind that it's usually a bad idea to kill threads from other threads - best off setting a flag and letting the thread process exit when it gets around to checking it.
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what I meant by killing is:
//this is done in the OnShowWindow function because I only need the thread
// running when dialog is shown.
if(bShow)
{
m_hThread = (HANDLE)_beginthread(reader,0,this);
}
else
{
::GetExitCodeThread(m_hThread,&dwExitCode);
if (STILL_ACTIVE == dwExitCode)
{
::TerminateThread(m_hThread,dwExitCode);
::CloseHandle(m_hThread);
};
m_hThread=NULL;
};
so how should I call "reader" and how is the definition of reader to avoid
compiler error when using __fastcall convention?.
regards.
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DaviziN wrote:
so how should I call "reader"
You do not explicitly call this function. It is the starting address for the secondary thread.
DaviziN wrote:
how is the definition of reader to avoid
compiler error when using __fastcall convention?.
The prototype for it should look like:
void __cdecl reader( void * );
"One must learn from the bite of the fire to leave it alone." - Native American Proverb
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