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What is the actual value of the string in your path variable, at the time you try to create the file?
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this is the value:
C:\Users\Antonio\Documents\file.txt
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OK, and does that directory exist and can you create that file manually? If so then check also the suggestions from other commenters below.
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Yes, this directory exist and I made the file manually.
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Use the class CStdioFile to read text file.
google for example, there are many.
Watched code never compiles.
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Rule number 0 when working with files. Always check return codes, so you know which call is failing.
Best guess is that when you call to Write() to the file, you do not have permissions, since your Open() call doesn't specify that permission. Maybe the create Permission implies this, but I'm not sure.
Chris Meech
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In theory there is no difference between theory and practice. In practice there is. [Yogi Berra]
posting about Crystal Reports here is like discussing gay marriage on a catholic church’s website.[Nishant Sivakumar]
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antonio343 wrote: , I get a error that it said: You dont have acces to this file.
Open the file using
CFile::modeReadWrite OR CFile::modeWrite it seems you don't have permission to write.
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I changed the mode by modeReadWrite and I get simbols like this:
<pre>쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌Y쳌쳌쳌쳌꣨ɷ쳌쳌偁泇¬</pre>
I also try this:
void CDlgResultados::loadFromFile(void)
{
CString path= GetUserHomeDir() + _T("\\Documents\\file.txt");
CStdioFile f1;
f1.Open(path, CFile::modeCreate | CFile::modeRead || CFile::typeText);
CStdioFile f(stdin);
TCHAR buf[100];
f1.ReadString(buf, 99);
m_Edit.SetWindowTextW(buf);
}
But I get simbols.
I think that the problem is the function ReadString doesnt get the text from the file, becouse the simbol that I get are the "rubbish" which is inicializated buf
modified 11-Oct-11 14:37pm.
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In your original code you were writing from an uninitialised buffer, hence the garbage recorded in your file. Check the logic of your code thus:
- Create the file with access for writing
- Write some text either from a constant string, or from some data built by the program
- Close the file
- Open the file with access for reading
- Read the text into a buffer
- Close the file
In each case check the results of your function calls to ensure that your code has completed without error. You can also create your file manually using Notepad or similar text editor.
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Yes, I know, I try to do that, and the file is created manually.
But I dont know how to read or write in mfc.
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See CFile[^], and in particular the Read() and Write() functions.
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antonio343 wrote: f1.Open(path, CFile::modeCreate | CFile::modeRead || CFile::typeText);
TCHAR buf[100];
f1.ReadString(buf, 99);
You are creating an empty file and then attempting to read from it. Is that really what you want?
Also, you may want to revise your usage of the | and || operators.
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Nooo.
I have a text file that I created manually,and I'd like to read the text from it.
I made a mistake when I write ||, but it is not the error
modified 11-Oct-11 20:20pm.
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`So, why are you asking for the the file to be Created?
if ( myFile.Open(path, CFile::modeCreate | CFile::modeRead ) )
| is a bitwise OR, || is a logical OR
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Yes you are right, I didnt know what mean this argument, if I dont put this argument, everything run rightly
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I continue to feel very fortunate that the vast majority of programming (that I see) is done in english.
I understand that with function/variable names in my own language I am at an advantage to those for whom they are in a different language.
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Is there any API which gives me list of Seial Ports available on system. I am trying to use QueryDosDevice () but its failed to provide any result .
Thanks
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pandit84 wrote: Is there any API which gives me list of Seial Ports available on system.
SerialPort.GetPortNames Method[^] is available as a.Net library method.
You could also try Another serial port enumerator[^] which uses a different approach to find serial ports by enumerating registry keys.
-OR-
Enumerating serial ports - W2K style [^]- Enumerating the serial ports using the SetupDi* API provided with Win2K and later
pandit84 wrote: QueryDosDevice () but its failed to provide any result .
I have also found this support page [^] on why QueryDosDevice fails.
modified 11-Oct-11 7:31am.
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Good answer overall, but considering this is the "C/C++/MFC" forum, don't think pointing out things in the .Net library are applicable. +5 for the other info though...
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Thank you for contributing...
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The CreateFile function creates or opens a file or I/O device.
The following code lists COM Ports in Win32..
#include <iostream>
#include <windows.h>
void main(){
char port_name[16];
for (int port_number = 1; port_number < 256; ++port_number)
{
port_number < 10 ?
sprintf(port_name, "COM%d", port_number) :
sprintf(port_name, "\\\\.\\COM%d", port_number);
HANDLE hFile = ::CreateFile(port_name,
GENERIC_READ | GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, 0, NULL);
if(hFile != INVALID_HANDLE_VALUE)
std::cout << port_name << std::endl;
else
{
DWORD err = GetLastError();
if (err == ERROR_ACCESS_DENIED ||
err == ERROR_SHARING_VIOLATION)
std::cout << port_name << std::endl;
}
CloseHandle(hFile);
}
}
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What if a COM port is in use at the time this code is run? It won't get listed.
The difficult we do right away...
...the impossible takes slightly longer.
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