File sharing violation with Nlog

Question

My C# DLL configures NLog to save to a file:

private static void SetupLogging()
{
    var Config = new NLog.Config.LoggingConfiguration();
    var logfile = new NLog.Targets.FileTarget("logfile")
    {
        FileName = m_LogFile,
        WriteBom = true,
        Layout = "${longdate}|${level:uppercase=true}|${logger}|${message:withException=true:exceptionSeparator=|}"
    };
    var logconsole = new NLog.Targets.ConsoleTarget("logconsole");

    Config.AddRule(LogLevel.Info, LogLevel.Fatal, logconsole);
    Config.AddRule(LogLevel.Debug, LogLevel.Fatal, logfile);

    LogManager.Configuration = Config;
}

My C++ application uses the DLL and performs various tasks. When it detects that there is an error it attempts to display the error log. It does this:

CFile file{};
CFileException ex{};

if (!file.Open(filePath, CFile::modeRead, &ex))
{
    TCHAR szError[_MAX_PATH]{};
    ex.GetErrorMessage(&szError[0], _MAX_PATH);
    AfxMessageBox(&szError[0], MB_OK | MB_ICONERROR);
    return;
}

The problem is that it raises an exception:

Yet, whilst that message is displayed I can actually open the file with NotePad.

So how can I get my application to open the log without getting this sharing violation?

Answer 1

I had to change how I was opening the log file:

if (!file.Open(filePath, CFile::modeRead | CFile::shareDenyNone, &ex))
{
    TCHAR szError[_MAX_PATH]{};
    ex.GetErrorMessage(&szError[0], _MAX_PATH);
    AfxMessageBox(&szError[0], MB_OK | MB_ICONERROR);
    return;
}

I needed to use CFile::shareDenyNone (no sharing restrictions).