如何在运行应用程序时不需要关闭文件时写日志文件？

Question

We have static class Logger in C#, where log file initializes at starting of application. Log files gets roll back (new log file gets created) after each 512 bytes . Now problem is, I am not able to open current log file externally, because it is being already open in my application.

I am not able to understand how to deal with this problem. How to open currently open log file, at same time it should not harm current operations on file.

Thanks.

Answer 1

Using FileShare.ReadWrite is crucial in your case. This should so the trick for you:

using (FileStream stream = File.Open("filePath", FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
    using (StreamReader reader = new StreamReader(stream))
    {
        while (!reader.EndOfStream)
        {
            // do your stuff here
        }
    }
}

Answer 2

To give you an accurate answer, I need to see the code for your logger. But I will explain the idea. Let's say the logger is using System.IO.File.Open() method to create/open the log file for writing. Use the overload of the Open() method that allows you to specify the FileShare parameter ( here is the link ) and specify FileShare.Read for that parameter. This will allow the applications to open the log file in read-only mode, so it will not harm the logging operation.