|
well, i cant give you a solution for this.
Any way check wheather the initialization is failing or not for the second dialog.
"When death smiles at you, only thing you can do is smile back at it" - Russel Crowe (Gladiator)
|
|
|
|
|
I am trying to get a int varibale into a char variable. any help here?
int temp = 20;
char *demo = (char) temp;
|
|
|
|
|
int temp =20;
char demo =(char) temp; // failed if temp > 128
|
|
|
|
|
Failed if temp >128?
what does it mean the addressing or the value?
|
|
|
|
|
elvis8900 wrote:
what does it mean the addressing or the value?
I believe it's the value.
(signed) char holds number from -127 to 128, due to its nature of 8-bit capacity (2^8).
|
|
|
|
|
-128 to 127.
Tim Smith
I'm going to patent thought. I have yet to see any prior art.
|
|
|
|
|
As a signed char is a 1 byte value (Range: -128 to 127), it can be used to hold values only within the range. The most significant bit (MSB) of the char variable is used to denote a negative or a positive value stored in it. If the MSB is ON (1), it means a negative value stored in the 7 bits remaining.
An unsigned char , on the other hand, can hold values ranging from 0 to 255.
An int is a 2 byte value (N.B.: In a 32-bit platform, it is a 4-byte value). Whichever way, if you're trying to store an int in a char variable, it will ONLY store the first byte (because char can only have a byte).
That means, if:
int n = 50;
char c = (char) n;
But, if:
int n = 300;
char c = (char) n; I hope this explains in detail.
Nirav
* Don't wish it was easier, wish you were better! *
|
|
|
|
|
Hello everyone.....
Could someone help me to find a suitable book for memory handling in MS Visual C++? I'm also interested about I/O handling.
Thx,
(w)
|
|
|
|
|
wallyka wrote:
find a suitable book for memory handling
Do you have a specific project in mind? Will you need to handle a lot of memory (> 1 GB)?
John
|
|
|
|
|
An excellent book I would recommend to have, is:
* Programming Applications for Microsoft Windows
- By Jeffrey Richter
- Microsoft Press.
* Don't wish it was easier, wish you were better! *
|
|
|
|
|
Hi,
Is it possible like on Unix to have a program dump a file with a stack trace for ease of debugging? If so, how? Thanks.
|
|
|
|
|
Yeah visual studio also has something like it. When you are debuging a application and you come with an exception, you click on retry and select debug/view/stack
"When death smiles at you, only thing you can do is smile back at it" - Russel Crowe (Gladiator)
|
|
|
|
|
Is there a Visual .NET 2003 equivalent of the .bsc file found in Visual C++ ver 6?
I am the handsome one in the crowd.
|
|
|
|
|
I'm a VB developer and i'm making a software that use a multiport video capture card.
I need to use directshow in order to select the video composite-in. I know i need to use the crossbar filter but i'm a novice in c++ programing.
Please help me to resolve my problem.
Thanks
|
|
|
|
|
Who can explain :
char *m="az";
cout << m << endl;
i=0;
cout << m[i++] << m[i++] << endl ;
i=0;
((cout.operator<<(m[i++])).operator <<( m[i++])).operator <<(endl) ;
Gives (Visual C++) 6.0 :
az
za
za
Thanks .
|
|
|
|
|
Using more than one ++ or -- operator on anything but a line by themselves is always risky. Looking at the statement:
cout << m[i++] << m[i++] << endl; the i++ statement gets executed first, and that value (1) is used with the [] operator.
"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)
|
|
|
|
|
sorry but the value of i used by the [] operator will be 0 ...
I think you're confused whith ++i ...
|
|
|
|
|
cout << i++ << i++ << endl; Stepping into the code for ostream& ostream::operator<<(int n) revealed that n had a value of 1 the first time, and a value of 0 the second time. Had the pre-increment operator been used instead, a subscript-out-of-range error would have been realized since the value of n would have been 2 the first time through. Separating the i++ operations into two statements solves all the problems.
"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)
|
|
|
|
|
Um, no.
The problem here is the undefined behavior of the multiple ++ operations which does get you into some problems.
int i = 0;
cout << m[i++] << endl;
This code would fetch the 0'th value. The ++ and -- operators are not risky when you know how to use them. They have well defined behaviors and undefined behaviors.
Tim Smith
I'm going to patent thought. I have yet to see any prior art.
|
|
|
|
|
In the second and third cout statements, you are modifying the value of i more than 1 time between sequence points. The result of this is undefined behavior - the compiler can output anything it wants.
|
|
|
|
|
// Loading bitmap image from file
bool ResLoad = SrcImage.LoadBMP24Image(szFileName);
Does anyone knows how this statement actualy loads the file?<br />
Below is the function for it i think
bool CBMPImage::LoadBMP24Image(const char* szFileName)
{
FILE* bmp = fopen (szFileName,"rb");
if (!bmp) return false;
BITMAPFILEHEADER BMPFileHeader;
BITMAPINFOHEADER BMPHeader;
fread (&BMPFileHeader,sizeof(BITMAPFILEHEADER),1,bmp);
fread (&BMPHeader,sizeof(BITMAPINFOHEADER),1,bmp);
if (BMPFileHeader.bfType != 0x4d42) {fclose (bmp); return false;}
if (BMPHeader.biSize != sizeof(BITMAPINFOHEADER)) {fclose (bmp); return false;}
if (BMPHeader.biPlanes != 1) {fclose (bmp); return false;}
if (BMPHeader.biCompression != BI_RGB) {fclose (bmp); return false;}
unsigned long BitColor = BMPHeader.biBitCount;
|
|
|
|
|
Goh,
Hope this helps...
FILE* bmp = fopen (szFileName,"rb"); // creates a FILE pointer szFileName
is char[] containing the file name that is passed to the operation.
if (!bmp) return false;//if null e.g no file found
BITMAPFILEHEADER BMPFileHeader;//create handles for the file
BITMAPINFOHEADER BMPHeader;
//fread does the actual loading
fread (&BMPFileHeader,sizeof(BITMAPFILEHEADER),1,bmp);
fread (&BMPHeader,sizeof(BITMAPINFOHEADER),1,bmp);
//check for valid headers date etc..
if (BMPFileHeader.bfType != 0x4d42) {fclose (bmp); return false;}
if (BMPHeader.biSize != sizeof(BITMAPINFOHEADER)) {fclose (bmp); return false;}
if (BMPHeader.biPlanes != 1) {fclose (bmp); return false;}
if (BMPHeader.biCompression != BI_RGB) {fclose (bmp); return false;}
unsigned long BitColor = BMPHeader.biBitCount;
so if success bmp contains a pointer to the bitmap file.
Does this help???? or do you need more info, not sure of your experience etc..
Ross W
|
|
|
|
|
I am a beginner trying to understand the codes
so where does the function knoe which file to create a file pointer. Where should the filename be placed
Thank alot
|
|
|
|
|
The key is szFilename, this will be a character array (string)
that will contain the path of the physical file, like "c:\SomeBitmap.bmp" look for the definition of szFilename
before the call below:
bool ResLoad = SrcImage.LoadBMP24Image(szFileName);
It may well of come from a dialog in which case it would have come from a member variable...
The key thing is that you could simply do this:
bool ResLoad = SrcImage.LoadBMP24Image("c:\\SomeBitmap.bmp");
If there is anything else please ask
|
|
|
|
|
Dear rw104,
Can I have your ICQ or msn number as i feel it is slow to ask you in this way.
I still got lots of queries. Can I sent you the file to take a look thx
Hui Beng
Thx
|
|
|
|