C # When reading and writing a file, the file is being used by another process, so the process cannot access the file

C # When reading and writing a file, the file is being used by another process. Therefore, the process cannot access the file and encounters an I/O failure.

The file "D: \ log.txt" is being used by another process, so the process cannot access the file.

Log.txt is a log file and may be written to it by another program from time to time.

I/O streams need to be used to read log files and display them in log query.

1. filestream FS = file. openread (URL );
Streamreader sr = new streamreader (system. Io. Stream) FS, system. Text. encoding. Default );

Error message: the file "D: \ log \ cargoabc \ logfilecargoabc.txt" is being used by another process. Therefore, this process cannot access the file.

2. streamreader sr = file. opentext (URL );

Error prompt: the error message "D: \ log \ cargoabc \ logfilecargoabc.txt" is being used by another process. Therefore, this process cannot access the file.

3. filestream FS = new filestream (URL, filemode. Open, fileaccess. Read, fileshare. readwrite );
Streamreader sr = new streamreader (FS, system. Text. encoding. Default );

Read correctly.

Summary:

In this case, you do not only need to open the TXT file in read-only mode, but also need to share the lock. You must also select the flieshare mode as readwrite. Because there are other programs to write to it at any time.