我在閱讀文件時是否正確？

Question

此代碼試圖讀取一個文件，但給錯誤，

System.IO.IOException: The process cannot access the file 'C:\doc.ics' because it is being used by another process. 
    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, Int32 bufferSize, FileOptions options) 
    at System.IO.StreamWriter.CreateFile(String path, Boolean append) 
    at System.IO.StreamWriter..ctor(String path, Boolean append, Encoding encoding, Int32 bufferSize) 
    at System.IO.StreamWriter..ctor(String path) 

我覺得這是在閱讀文件導致了問題的代碼，它工作正常的開發和集成服務器，但不是生產服務器上。

private byte[] ReadByteArrayFromFile(string fileName) 
    { 
     byte[] buffer = null; 
     FileStream filestrm = new FileStream(fileName, FileMode.Open, FileAccess.Read); 
     BinaryReader binaryread = new BinaryReader(filestrm); 
     long longNumBytes = new FileInfo(fileName).Length; 
     buffer = binaryread.ReadBytes((int)longNumBytes); 
     return buffer; 
    } 

Answer 1

你沒有做正確的：每當你打開一個文件流，你必須處理它。

這將這樣的伎倆：

private byte[] ReadByteArrayFromFile(string fileName) 
    { 
     byte[] buffer = null; 

     using(FileStream filestrm = new FileStream(fileName, FileMode.Open, FileAccess.Read)) 
     using(BinaryReader binaryread = new BinaryReader(filestrm)) 
     { 
      long longNumBytes = new FileInfo(fileName).Length; 
      buffer = binaryread.ReadBytes((int)longNumBytes); 
     } 

     return buffer; 
    } 

using報表將調用Dispose()你，即使有異常拋出！

而且，當然，你會避免文件鎖定。

Take a look at this article.

Answer 2

您應該使用FileStream內using聲明，以確保它是正確關閉和設置：

using (FileStream fs = File.OpenRead(path)) 
{ 
    ... 
} 

MSDN

Answer 3

用途：

var bytes = File.ReadAllBytes(@"path"); 

取而代之！