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asp.net - 将文件作为 varbinary(max) 保存到 SQL 的问题

问题描述

所以，我有一个 web 应用程序将一些附件保存到 SQL 数据库中VarBinary(max)，一切运行顺利，直到我意识到当我从数据库中下载附件时，文件与原始大小相比非常大，所以一个 400KB 的文件，下载一个将是5MB！我做错了什么？

上传代码为：

Dim img As FileUpload = CType(FileUpload1, FileUpload)
Dim imgByte As Byte() = Nothing
If img.HasFile AndAlso Not img.PostedFile Is Nothing Then
    Dim File As HttpPostedFile = FileUpload1.PostedFile
    imgByte = New Byte(File.ContentLength - 1) {}
    File.InputStream.Read(imgByte, 0, File.ContentLength)
    cmd.Parameters.AddWithValue("@filetype", Path.GetExtension(FileUpload1.FileName).ToLower)
    cmd.Parameters.AddWithValue("@attachment", imgByte)
End If

下载代码：

Dim imagem As Byte() = CType((dr("attachment")), Byte())
Response.Clear()
Response.AddHeader("Cache-Control", "no-cache, must-revalidate, post-check=0, pre-check=0")
Response.AddHeader("Pragma", "no-cache")
Response.AddHeader("Content-Description", "File Download")
Response.AddHeader("Content-Type", "application/force-download")
Response.AddHeader("Content-Transfer-Encoding", "binary\n")
Dim fileName As String = "attachment; filename=" & "DOC_REFNO_" & "_" & regref_txt.Text.Replace("/", "_") & dr("filetype")
Response.AddHeader("content-disposition", fileName)
Response.BinaryWrite(imagem)

谢谢你们。

标签： asp.netsql-servervb.netvarbinarymax

解决方案

所以我发现下载的代码不正确，我把它改成下面的代码，完美运行。

 Dim imagem As Byte() = CType((dr("attachment")), Byte())
            Response.Buffer = True
            Response.Charset = ""
            Response.Cache.SetCacheability(HttpCacheability.NoCache)
            Response.ContentType = ContentType
            Dim fileName As String = "attachment; filename=" & "DOC_REFNO_" & "_" & regref_txt.Text.Replace("/", "_") & dr("filetype")

            Response.AddHeader("content-disposition", fileName)
            Response.BinaryWrite(imagem)
            Response.Flush()
            Response.End()

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