1) 如果您使用 SQL Server，我个人更喜欢将上传的文件存储在 varbinary(max) 字段中，并通过其唯一 ID 来使用它们。然后您不必担心名称冲突或数据库与文件系统不同步。这还允许您的上传过程独立于父表单的插入。
下面的示例展示了如何从文件流（和元数据）中获取文件流（和元数据）FileUpload控制在一个FormView并将其作为参数提供给 SQL 存储过程。然后，一个类实现IHTTPHandler用于从数据库检索文件。
2）就清除临时文件而言，我会将每个上传的文件与临时主记录相关联，以便将它们捆绑在一起。当确认真正的母版后，删除临时母版（以及来自真实母版的参考文件）。然后定期运行 SQL 代理作业以删除早于 X 时间的临时主文件和关联文件。
Saving:
Protected Sub DetailsView1_ItemInserting(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DetailsViewInsertEventArgs) Handles DetailsView1.ItemInserting
Dim objUploader As FileUpload = DetailsView1.FindControl("fuFile")
If objUploader.HasFile Then
Dim strFileName As String = objUploader.PostedFile.FileName
strFileName = strFileName.Substring(strFileName.LastIndexOf("\") + 1)
Dim objFileStream As System.IO.Stream = objUploader.PostedFile.InputStream
Dim arrFileImageByteArray(objFileStream.Length) As Byte
objFileStream.Read(arrFileImageByteArray, 0, objFileStream.Length)
e.Values.Insert(0, "FileImage", arrFileImageByteArray)
e.Values.Insert(1, "FileName", strFileName)
e.Values.Insert(3, "PostingDate", Now)
e.Values.Insert(5, "Application", "CorpForms")
Else
e.Cancel = True
objMessages.Add(New StatusMessage(MessageType.Warning, "File Upload canceled. No file was selected."))
End If
End Sub
检索：
Public Class FileServiceHandler : Implements IHttpHandler
Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
Dim idFileID As Guid
If context.Request.QueryString("FileID") IsNot Nothing Then
Dim strFileID As String = context.Request.QueryString("FileID")
Try
idFileID = Guid.Parse(strFileID)
Catch ex As Exception
Throw New Exception("Unable to parse File ID")
End Try
End If
Dim objConnection As New SqlConnection(ConfigurationManager.ConnectionStrings("PublicWebConnectionString").ConnectionString)
Dim objCommand As SqlCommand = objConnection.CreateCommand
Dim objReader As SqlDataReader
objCommand.CommandType = Data.CommandType.StoredProcedure
objCommand.CommandText = "spGetUploadedFile"
objCommand.Parameters.AddWithValue("FileID", idFileID.ToString)
Dim arrFileImage() As Byte = Nothing
Dim strFileName As String = String.Empty
Try
objConnection.Open()
objReader = objCommand.ExecuteReader
While objReader.Read
If Not IsDBNull(objReader("FileImage")) Then
arrFileImage = objReader("FileImage")
End If
If Not IsDBNull(objReader("FileName")) Then
strFileName = objReader("FileName")
End If
End While
Catch ex As Exception
Throw New Exception("There was a problem retreiving the file: " & ex.Message)
End Try
If objConnection.State <> Data.ConnectionState.Closed Then
objConnection.Close()
End If
If arrFileImage IsNot Nothing Then
context.Response.Clear()
context.Response.AddHeader("content-disposition", "attachment;filename=" & strFileName)
context.Response.BinaryWrite(arrFileImage)
context.Response.End()
Else
context.Response.ContentType = "text/plain"
context.Response.Write("Unable to retrieve file ID# " & idFileID.ToString)
End If
End Sub
Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
Get
Return True
End Get
End Property
End Class
文件检索路径中的Web.Config：
<configuration>
<system.web>
<httpHandlers>
<add verb="GET" path="*" type="MyNamespace.FileServiceHandler" />
</httpHandlers>
</system.web>
<system.webServer>
<handlers>
<add name="MyNamespace.FileServiceHandler" path="*" verb="*" type="MyNamespace.FileServiceHandler" resourceType="Unspecified" preCondition="integratedMode" />
</handlers>
</system.webServer>
</configuration>
