Can't read all lines in file that being used b

2020-04-16 05:59发布

I am trying to read all lines of log file that being used by some program.

When I tried to do it I am receiving exception:

System.IO.IOException was unhandled  : file used by another process

So I searched on the web and found number of solutions:
C# exception. File is being used by another process
Read log file being used by another process
What's the least invasive way to read a locked file in C# (perhaps in unsafe mode)?
C# The process cannot access the file ''' because it is being used by another process
File is being used by another process
http://coding.infoconex.com/post/2009/04/21/How-do-I-open-a-file-that-is-in-use-in-C

The common solutions are to use using to wrap the FileStream and add the FileShare.ReadWrite.

I tried those solutions but I am still receiving the exception that the file is being used by another process.

In my below code I open the file D:\process.log to make the file used (for testing) and then trying to open the file.
The exception is on row:

 using (FileStream fileStream = File.Open(i_FileNameAndPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))

CODE:

 private void openToolStripMenuItem_Click(object sender, EventArgs e)
    {
        OpenFileDialog openFileDialog = new OpenFileDialog();

        DialogResult dialogResult = openFileDialog.ShowDialog();
        if (dialogResult == DialogResult.OK)
        {
          listView.Items.Clear();
          File.Open(@"D:\process.log", FileMode.Open);  //make the file being used
          String fileNameAndPath = openFileDialog.FileName;
          String[] fileContent = readAllLines(fileNameAndPath);
        }
}

private String[] readAllLines(String i_FileNameAndPath)
{
    String[] o_Lines = null;
    int i = 0;
    using (FileStream fileStream = File.Open(i_FileNameAndPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
    {
        using (StreamReader streamReader = new StreamReader(fileStream))
        {
            while (streamReader.Peek() > -1)
            {
                String line = streamReader.ReadLine();
                //o_Lines[i] = line;
                i++;
            }
        }
    }

    return o_Lines;
}

标签: c# file
1条回答
够拽才男人
2楼-- · 2020-04-16 06:40

use an overload of File.Open in your menuclick event handler like this:

File.Open(@"C:\process.log", FileMode.Open,FileAccess.ReadWrite, FileShare.ReadWrite);

The last param is a value specifying the type of access other threads have to the file.

see this article from msdn

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