2010-07-15 115 views
3

我正在开发一个应用程序,用于检查单独程序(不是我写的)对文件所做的更改。是否可以读取锁定文件?

如果检测到更改,它会打开文件,读取最后一行,然后关闭文件。

我用下面的代码,以确保我的程序不会尝试锁定文件,但只打开它在读模式:

FileStream fs = 
    new FileStream(
     _scannerFilePath, 
     FileMode.Open, 
     FileAccess.Read, 
     FileShare.ReadWrite); 
StreamReader sr = new StreamReader(fs); 
var str = sr.ReadToEnd(); 
sr.Close(); 
fs.Close(); 

不幸的是,尽管如此,我每当我的程序尝试读取文件时,仍然会出现以下错误:

System.IO.IOException was unhandled 
    Message="The process cannot access the file 'D:\\LSDATA\\IdText.txt' because it is being used by another process." 
    Source="mscorlib" 
    StackTrace: 
     at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) 
     at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy) 
     at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share) 
     at LiquorSafe.Verification.Main.CheckLastScannedUser(String changedFileName) 
     at LiquorSafe.Verification.Main.OnChanged(Object sender, FileSystemEventArgs e) 
     at System.IO.FileSystemWatcher.OnChanged(FileSystemEventArgs e) 
     at System.IO.FileSystemWatcher.NotifyFileSystemEventArgs(Int32 action, String name) 
     at System.IO.FileSystemWatcher.CompletionStatusChanged(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* overlappedPointer) 
     at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP) 
    InnerException: 

是否有任何可能的原因?

难道是其他程序以某种方式读锁定该文件,从而阻止我甚至读它?

回答

4

是的,您可以在所谓的专用模式中打开文件。这意味着没有人能够读取或写入该文件。

如果您看一下File.Open()函数。有一个参数FileShare可以设置为None

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