尝试从字节流中打开docx文件-文件损坏错误

Question

we consistently get a file corrupted error message when opening a docx file from a saved bytestream, evry other file type works just ok

Below is code from a sample form that replciate the issue

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

    'Objective is to be able to copy a file to a bytestream then create a new document from that stream  and then opne it.
    'This replicates the behaviour of our primary application where it stores and retrieves the stream from a database
    'With docx files we consistently experience some sort of corruption in the write of the original file
    'When selecting .doc or other format files we do not encounter the same problem

    'use selected file
    Dim _o1 As String = TextBox1.Text
    'get its bytestream
    Dim fs As New FileStream(_o1, FileMode.Open, FileAccess.Read)
    Dim byteStream(Convert.ToInt32(fs.Length)) As Byte
    fs.Read(byteStream, 0, Convert.ToInt32(fs.Length))

    'create a new file and use the bytestream to create it and save to disk
    Dim _o As String = "C:\" & Now.Ticks & getNewFileName()

    Dim fs1 As New FileStream(_o, FileMode.OpenOrCreate, FileAccess.Write)
    Using bw As New BinaryWriter(fs1)
        bw.Write(byteStream)
        bw.Flush()
    End Using

    'open the new document
    System.Diagnostics.Process.Start(_o)
    Application.DoEvents()
End Sub
Private Function getNewFileName() As String
    Dim fi As New FileInfo(TextBox1.Text)

    Return Now.Ticks.ToString & fi.Name
End Function
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    OpenFileDialog1.InitialDirectory = "c:\"
    OpenFileDialog1.FilterIndex = 2
    OpenFileDialog1.RestoreDirectory = True
    OpenFileDialog1.Filter = "docx files |*.docx"

    If OpenFileDialog1.ShowDialog() = System.Windows.Forms.DialogResult.OK Then
        TextBox1.Text = OpenFileDialog1.FileName

    End If

End Sub

Answer 1

Forgive me, but that is some messed up code.

Dim _o As String = "C:\" & Now.Ticks & getNewFileName()

will become...

Dim _o As String = "C:\" & Now.Ticks & Now.Ticks.ToString & fi.Name

Example result "C:\\" "634015010433498951" "634015010433498951" "FileName.txt" is probably not what you are expecting unless you intend to subtract the two tick counts to determine how long it took to populate FileInfo.

Your FileStream corruption could be a encoding issue, off by one file length issue, or even a long filename in a deep path could a problem. Instead of using FileStream, this code should work fine:

Dim sourceFile As String = TextBox1.text
Dim fi As New System.IO.FileInfo(sourceFile)
Dim destFile = "C:\" & Now.Ticks & fi.Name
fi.CopyTo(destFile)
'open the new document   
System.Diagnostics.Process.Start(destFile)