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"this" is a key word to refer to the currently instantiated class that the method is in so if you had:
<br />
public ref class FrmMyCoolForm : public System::Windows::Forms::Form<br />
{<br />
public:<br />
FrmMyCoolForm(void)<br />
{<br />
this->Visible = false;<br />
}<br />
}<br />
You would be changing the visiblility of the object that the method was called from.
(Probably not close to a textbook definition but hope it makes sense)
EDIT: Here is a definition C++ keyword used in a member function to point at the object currently being operated on.
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THanks- I inderstad that. I'm referring to the CreateGraphics.
CreateGraphics is a "method" when a WHAT is instantiate.
int x;
this->Foo() == x.Foo() //OK
this.CreateGraphics() // What's "this"? in THIS case
Is it Graphics g?
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Hi,
I want to save and open a file in Win32,example I want store a array or matrix in a file in Win32.Please help me.
Thanks.
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Hi!
You can use Win32 API:
for example:
DWORD ByteWriten , ByteRead;
int MyArray[5] = {2534 ,3535, 3534,4576,54};
int ReadArray[5];
HANDLE MyHand =
CreateFile("c:\\sampfile" , GENERIC_WRITE | GENERIC_READ , FILE_SHARE_READ | FILE_SHARE_WRITE ,
NULL , CREATE_ALWAYS , FILE_ATTRIBUTE_NORMAL , NULL); //Create Handle To File
WriteFile(MyHand , (void *)MyArray , 10/* 5*2(int) */ , &ByteWriten , NULL);
//Write Array to file
ReadFile(MyHand , (void *)ReadArray , 10 , &ByteRead , NULL);
//Read Array From file.
CloseHandle(MyHand);
CRTE_Tech
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insertion and deletion using linear linked list
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Anonymous wrote:
insertion and deletion using linear linked list
Good, you working on it?
-prakash
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hello
: i am pursuing A Level From DOEACC in india.
: i wanted a Project in c++ relating following topics or something new like planets, solar eclipse etc, Or library management or bank management or railway reservation which includes any of the topics like class, inheritance, file handling,arrays.
: or if anyone can suggest a project program related to the above topics(games, etc.).
: i would be grateful to u if u reply.
: can u tell me a site which has these type of programs.
:
: thanks
: gagit
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Can anyone please tell me why this code code gives a segmentation? The
class NonLeafTrieNode<br />
{<br />
public:<br />
NonLeafTrieNode(){};<br />
NonLeafTrieNode(char);<br />
<br />
private:<br />
friend class Trie;<br />
<br />
NonLeafTrieNode **ptrs;<br />
char *letters;<br />
int endOfWord;<br />
bool isLeaf;<br />
};
The code below are in the Trie class and I use this to access the isLeaf variable in the class.
int flag = p->ptrs[pos]->isLeaf;<br />
if (!(pos == -1) && flag)
If I keep the isLeaf variable a boolean the code gives a segmentation fault, but whenever I make it a integer the code works perfectly.
Can anyone tell me why this happens.
Thanks a lot
LiquidE_SA
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A very strange bug; sounds to me like some kind of memory access splat. There's not too much to go on from your example, but the fact you're using an array (ptrs[]) and that changing the size of the class (by changing bool to int [see note]) causes a crash, sounds to me like something somewhere isn't accessing the right memory.
Ensure you've allocated enough memory for ptrs[] and that 'pos' is in within a valid range - if that doesn' solve it perhaps post a bit more information - whereabouts is the crash? I assume it's on the 'p->ptrs[pos]->isLeaf' line.
Matt Godbolt
Engineer, ProFactor Software
StyleManager project
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I have one function with 3 parameters.
In that function I have one switch case statement which depends on first parameter of my function. Nearly the cases are 28 to 30. For each case there is another sub switch case which depends on the second parameter of my function with more cases. For different cases I am allocating different classes memory in one class object. At last the function returning that object. For this concept implementation is there any simple implementation or any other logic, any template. The cases are increasing because of new implementations. Expecting some better solution.
The sample code is:
CMyCls* CEmr:GetCls(DWORD dwDId, DWORD dwClsId,BOOL bFe)
{
CMyCls* pCls = NULL;
switch (m_byClsFamily)
{
case _FAMILY_1_:
switch (dwClsId)
{
case 0x8242:
if (bFe || (dwDId == DB_18C453))
pCls = new CMyCls1;
break;
case 0x8252:
if (bFe || (dwDId == DB_18C452))
pCls = new CMyCls2;
break;
...
...
}
break;
case _FAMILY_2_:
...
case _FAMILY_3_:
...
case _FAMILY_4_:
...
...
break;
}
return pCls;
}
Here All CMyCls1, CMyCls2, CMyCls3, CMyCls4,... all are derived from a class named "CMyCls".
My actual problem is, I need to simplify my switch case. I am searching for the easyest way even the cases may be increased in near future. In different case I need to create different Calss's object. Creating object is not a problem. But the switch case becomeing very big. I am looking for any good template or any other solution.
Any help very thankful to them. It is urgent.
Nice talking to you. 
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Hi, everybody!
I am trying to build a numerical simulation which stores data in a mat-file. My program was written by C++ and runs on Linux. I want to store output data in mat-file because it's convenient to analyze in matlab. I don't know how to write the data to a mat-file and how to buid a C++ program integrated with matlab in Linux.
Please help me.
Thanks a lot!
h
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Hello, guys!
I'm not found at the WEB any good link with example of implementation of DirectShow's DVD seeking. How I can correctly perform DVD (also VOB files) seeking with Direct Show Interface?
Thanks.
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I m not getting how to run music or .bmp files in c++. I have a bit of idea that a third party tool will be needed in doing that, but I dont know exactly how it is done. Please if any body can sort out this problem.
Inder Gujral
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try createprocess.
-prakash
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This was a very stupid answer.Createprocess will not help at all in linkin the audio driver with compiler.
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Hai friends,
Anyone there to help me to kill a process running in task manager using VC++ or C++.. i cant proceed my my work without this solution... past three days i was back of this.. plz help me
Regards
Hareesh
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Its really bad that you have kill a process to get your work done unless that is not your developed process.
-prakash
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Hello..
I'm trying to read in data coming from the serial port.. the data can come in at any time (so the program has to monitor the serial port continuously, thats why i'm using a while loop in my code below). I'm reading Tag IDs (strings) which are formatted into packets.. each packet starts with the '&' character and ends with the '$' character..
Right now I read in the whats coming from the serial port (using a infinite while loop) into a string and then tokenize that string according to my packet delimiters.. the problem is that Readfile is returning after getting part of the tag ID packet and then the remaining part of the tag ID packet comes the next time the while loop is called.. I think its something to do with the way I use the readfile function in the while loop..my code is given below.. Please advice..
Thank you for your help..
<br />
<br />
char buffer[200000];<br />
<br />
while (true)<br />
{<br />
printf("In while\n"); <br />
<br />
memset(buffer, 0, sizeof(buffer));<br />
if (ReadFile(h, buffer, sizeof(buffer)-1, &bytesRead, 0))<br />
{<br />
printf("Read file has a result\n"); <br />
if (bytesRead != 0)<br />
{<br />
printf("Got some bytes\n"); <br />
printf ("%s", buffer);<br />
<br />
printf( "Tokens in buffer:\n" );<br />
<br />
token = strtok(buffer, "&$" );<br />
<br />
while( token != NULL )<br />
{<br />
<br />
printf( " %s\n", token );<br />
<br />
token = strtok( NULL, "&$" );<br />
}<br />
<br />
}<br />
<br />
else <br />
{<br />
printf("No bytes read\n"); <br />
}<br />
}<br />
<br />
else {<br />
printf("Readfile didnt give proper result \n"); <br />
}<br />
Sleep(200);<br />
}<br />
<br />
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Hi all -
My project requirement says to create a daemon program to communicate with a DLL for data exchange. I have some questions regarding the daemon program. Any pointers would be helpful.
1. Daemon is equivalent to "Services" in Windows? A service can be non web-based as well? (I search on internet, I find only web based services every where)
2. How do you create these services in Visual Studio 6.0.
which technology you use?
3. Is the service going to be an ATL COM+ based service?
4. Any articles, knowledge base in internet for these?
Thanks in advance
Misha
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misha_grewal wrote:
1. Daemon is equivalent to "Services" in Windows? A service can be non web-based as well? (I search on internet, I find only web based services every where)
yes, it is.
misha_grewal wrote:
How do you create these services in Visual Studio 6.0.
which technology you use?
you can use ATL wizard.
misha_grewal wrote:
Any articles, knowledge base in internet for these?
http://www.codeproject.com/system/windows_nt_service.asp#xx490705xx[^]
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Hello, I basically want to make a function that will take in any interator and perform operations on it. For example, if I had the function: >mySort( iterator, iterator ) I would be able to pass in a std::vector iterator, a std::set iterator, a std::list or any iterator defined for a customized container, or any other STL container. Is this possible??
Mike - I love to program!
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