Question

我正在制作一个加密程序，它也可用作记事本（CryptoMatic）。有一个Open函数，代码如下：

    Dim r As New StreamReader(filename)
    Dim text As String = r.ReadToEnd
    txtFileContents.text = text

    r.Dispose()
    r.Close()

现在有保存并另存为按钮保存按钮检查文件是否先前已保存。如果是，那么我试图用以下代码写入该文件：

    Dim myFileStream As New System.IO.FileStream(filename, FileMode.Append, FileAccess.Write, FileShare.None)
    myFileStream.Lock(0, 100)

    Dim myWriter As New System.IO.StreamWriter(myFileStream)
    myWriter.WriteLine(text)

    myWriter.Flush()
    myWriter.Close()
    myFileStream.Close()

    myFileStream.Unlock(0, 100)

现在当我按下保存按钮时，它会出现以下错误：

    The process cannot access the file 'C:\Users\VisualTech\Documents\Visual Studio            2010\Projects\CryptoMatic Update\CryptoMatic Update\bin\Debug\text.txt' because it is being    used by another process.

并且申请停止，有人可以帮助我吗？

Answer 1

我已经尝试过上面的代码并注意到两件事：

您不需要myFileStream.Lock电话，因为您已经打开它 FileShare.None
致电后，您无法拨打myFileStream.Unlock(0, 100) myFileStream.Close()

所以我以这种方式重写了你的代码。

Sub Main
    Dim text = "This is a text to write in the stream"
    Using myFileStream As New System.IO.FileStream("D:\temp\testlock.txt", FileMode.Append, FileAccess.Write, FileShare.None)
        Using myWriter As New System.IO.StreamWriter(myFileStream)
            myWriter.WriteLine(text)
        End Using
    End Using
End Sub

用IO.StreamReader读取文件后无法写入文件

1 个答案: