无法读取文件中被另一个进程使用的所有行

Question

我正在尝试读取某些程序正在使用的日志文件的所有行。

当我尝试这样做时，我收到异常：

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

所以我在网上搜索，找到了很多解决方案：
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

常见的解决方案是使用using 包裹FileStream 并添加FileShare.ReadWrite。

我尝试了这些解决方案，但我仍然收到另一个进程正在使用该文件的异常。

在下面的代码中，我打开文件 D:\process.log 以使用该文件（ 用于测试 ），然后尝试打开该文件。
异常在行：

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

代码：

 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;
}

Answer 1

在您的菜单点击事件处理程序中使用 File.Open 重载，如下所示：

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

最后一个参数是一个值，指定其他线程对文件的访问类型。

见this article from msdn

无法读取文件中被另一个进程使用的所有行

Can't read all lines in file that being used by another process

c#

file