I am just creating a basic file handling program. the code is this:
#include <stdio.h>
int main()
{
FILE *p;
p=fopen("D:\\TENLINES.TXT","r");
if(p==0)
{
printf("Error",);
}
fclose(p);
}
This is giving Error, I cannot create files tried reinstalling the compiler and using different locations and names for files but no success. I am using Windows 7 and compiler is Dev C++ version 5
I am from electric engineer background, therefore my knownledge is small about C#,DLL,etc.... I want to use c function into a C#. I know there is a couple post about that but I didn't find one that is enough simple.
Currently, I got C function call windows API to read/write on the USB port. First to create a .dll do I need a header file? Because I got the following function decleration function into a header. The examples that I saw on stack overflow and Internet only use a simple .c file, Can I get rid of the header files?
__declspec(dllexport) LMUSB_HANDLE __stdcall InitializeDevice(unsigned short usVID,
unsigned short usPID,
LPGUID lpGUID,
BOOL *pbDriverInstalled);
__declspec(dllexport) LMUSB_HANDLE __stdcall InitializeDeviceByIndex(unsigned short usVID,
unsigned short usPID,
LPGUID lpGUID,
DWORD dwIndex,
BOOL bOpenDataEndpoints,
BOOL *pbDriverInstalled);
__declspec(dllexport) BOOL __stdcall TerminateDevice(LMUSB_HANDLE hHandle);
__declspec(dllexport) BOOL __stdcall WriteUSBPacket(LMUSB_HANDLE hHandle,
unsigned char *pcBuffer,
unsigned long ulSize,
unsigned long *pulWritten);
__declspec(dllexport) DWORD __stdcall ReadUSBPacket(LMUSB_HANDLE hHandle,
unsigned char *pcBuffer,
unsigned long ulSize,
unsigned long *pulRead,
unsigned long ulTimeoutMs,
HANDLE hBreak);
__declspec(dllexport) BOOL __stdcall Endpoint0Transfer(LMUSB_HANDLE hHandle, UCHAR ucRequestType,
UCHAR ucRequest, USHORT usValue,
USHORT usIndex, USHORT usLength,
PUCHAR pucBuffer, PUSHORT pusCount);
Second point, do I need to write __declspec(dllexport) in the cpp file? Here an function from the cpp:
extern "C" __declspec(dllexport) BOOL PASCAL EXPORT TerminateDevice(LMUSB_HANDLE hUSB)
I got no idea what "BOOL PASCAL EXPORT" does, this code is recycled from a furnisher project.
Finaly, when the DLL is properly build. How I import it in the C# project? I tried the following but without success :
[DllImport("lmusbdll.dll")]
I see that you could use right click on the project and add reference but Visual Studio pop-up an error message:
A reference to "DLL path" could not be added. Please make sure that the file is accessible, and that it is a valid assembly or COM component.
[EDIT]
I tried the following solution , but when I tried to reference the header file in my c# project. I still get the message that I cannot reference the file.
This question already has an answer here:
Taking the following example:
void foo(const int foobar);
Is the keyword const meaningful?
I just got to know there are multiple consoles in Netbeans when working on a C-program. Please let me know what are the differences between them and when will they be used. Please see the screenshot
So, the thing is, this program checks if there are duplicate files in a directory. It uses mostly the windows.h library. To spare code, all the file paths are stored in the buffer finalizedList. The list is always correct, don't worry about it.
To show you the problem, here are the files in the directory:
Now, anytime I run the program while "hello.cpp" is in the directory, this is the output of the program:
Creating list...
Finalizing list...
Starting compare procedure...
Checking: duplicate_delete.exe vs. hello - Copy.txt --> DIFFERENT
Checking: duplicate_delete.exe vs. hello.cpp --> DIFFERENT
Checking: duplicate_delete.exe vs. hello.txt --> DIFFERENT
Checking: hello - Copy.txt vs. hello.cpp --> DIFFERENT
Checking: hello - Copy.txt vs. hello.txt --> DIFFERENT
Checking: hello.cpp vs. hello.txt --> DIFFERENT
Finished.
Press any key to continue . . .
But, when I delete that file the output is this:
Creating list...
Finalizing list...
Starting compare procedure...
Checking: duplicate_delete.exe vs. hello - Copy.txt --> DIFFERENT
Checking: duplicate_delete.exe vs. hello.txt --> DIFFERENT
Checking: hello - Copy.txt vs. hello.txt --> DUPLICATE
Finished.
Press any key to continue . . .
Now... Why does that happen? Or to put it in a better way, how can that happen?
Here are parts of the code:
#include <windows.h>
#include <stdio.h>
HANDLE file1, file2;
const WCHAR * finalizedList[] = { L"duplicate_delete.exe", L"hello - Copy.txt", L"hello.txt", L"hello.cpp" };
WCHAR deleteList[4][1024];
DWORD fileListP, deleteListP;
DWORD openFile1(WCHAR path[1024]);
DWORD openFile2(WCHAR path[1024]);
DWORD compare();
void startCompare();
int main(void)
{
fileListP = 4;
printf_s("Starting compare procedure...\n");
startCompare();
printf_s("Finished.\n");
_fcloseall();
system("pause");
return 0;
}
DWORD openFile1(WCHAR path[1024])
{
if ((file1 = CreateFile(path, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) return 0;
return 1;
}
DWORD openFile2(WCHAR path[1024])
{
if ((file2 = CreateFile(path, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) return 0;
return 1;
}
DWORD compare()
{
DWORD a, b;
BYTE byte1, byte2;
while (1)
{
ReadFile(file1, &byte1, 1, &a, NULL);
ReadFile(file2, &byte2, 1, &b, NULL);
if (a != b) return 1;
if (byte2 != byte1) return 1;
if (a == 0 && b == 0) break;
}
return 0;
}
void startCompare()
{
WCHAR currentFile[1024], comparedFile[1024];
DWORD i, j;
i = 0;
for (j = 0; j < fileListP; ++j)
{
lstrcpy(currentFile, finalizedList[j]);
if (!openFile1(currentFile)) wprintf(L"File \"%ls\" couldn not be opened for comparing.\n", currentFile);
else
{
for (i = j + 1; i < fileListP; ++i)
{
lstrcpy(comparedFile, finalizedList[i]);
if (!openFile2(comparedFile)) wprintf(L"File \"%ls\" couldn not be compared with file \"%ls\".\n", currentFile, comparedFile);
else
{
if (!compare())
{
wprintf(L"Checking: %ls vs. %ls --> DUPLICATE\n", currentFile, comparedFile);
lstrcpy(deleteList[deleteListP], currentFile);
++deleteListP;
}
else
{
wprintf(L"Checking: %ls vs. %ls --> DIFFERENT\n", currentFile, comparedFile);
}
CloseHandle(file2);
}
}
CloseHandle(file1);
}
}
}
Now... Of course, when I'm to check the program without the hello.cpp file I just delete it from the finalizedList array and make fileListP equal to 3. This is the minimal code that will work.
I need to know if there is something like SignalR but for Winforms, some nuggets or library for paid, someone who can guide me please.
The beginning of my problem is that I have the need to obtain data automatically when the table is updated.
Thanks.
I have an external singlethreaded program that needs to be run multiple hundred times with different parameters. To make it faster I want to run it once for each core at the same time. To do that I used Parallel.ForEach running on a list with the different parameters to pass to the external program:
var parallelOptions = new ParallelOptions {
MaxDegreeOfParallelism = Environment.ProcessorCount // 8 for me
};
Parallel.ForEach(ListWithAllTheParams, parallelOptions, DoTheStuff);
...
private void DoTheStuff(ParamType parameter, ParallelLoopState parallelLoopState, long index)
{
// prepare process parameters etc.
theProcess.Start();
theProcess.WaitForExit();
}
Pretty straightforward and works nicely... until the last ~10 items - they don't get parallelized for some reason and just run one after another. I've confirmed this by looking at the cpu usage and the running programs in the Task Manager.
This does not happen when I populate the parameter list with only a few (say, 10) items.
Can somebody explain this behavior to me? Any hints or tips appreciated!