我在阅读文件时做得对吗?

时间:2013-03-21 10:04:18

标签: c# asp.net file file-upload .net-2.0

此代码尝试读取文件但发出错误

   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)

我认为这是在读取文件时导致问题的代码,它在开发和集成服务器上运行良好,但在生产服务器上运行不正常。

    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;
    }

3 个答案:

答案 0 :(得分:5)

使用:

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

相反!

答案 1 :(得分:3)

您应该在FileStream语句中使用using以确保它已正确关闭并处置:

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

MSDN

答案 2 :(得分:2)

你做得不对:每当你打开一个文件流时,你必须处理它

这样可以解决问题:

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语句会为您调用Dispose(),即使引发了异常!

当然,您将避免文件锁定。

Take a look at this article.