使用 Microsoft.XMLHTTP 和 progres VBA 将文件上传到 Azure Blob 存储

Question

我正在尝试使用 VBA for MS Access 中的 Microsoft.XMLHTTP 通过进度跟踪将文件上传到存储。没有进度跟踪的上传工作正常，但我需要进度跟踪，特别是对于较大的文件。

我对这条线有疑问：

 xmlHttp.send fileData

err: 参数不正确... 我尝试将文件分成 5 部分并上传，但我做错了。 这是片段：

 Public Sub UploadToAzureBlob(filePath As String, fileName As String)
    Dim adoStream As Object
    Dim xmlHttp As Object
    Dim responseStatus As Long
    Dim sUrl As String
    Dim fileSize As Long
    Dim bytesSent As Long
    Dim chunkSize As Long
    Dim fileData() As Byte
    Dim progressForm As Form
    Dim numParts As Long

    'On Error GoTo ErrHandler

    filePath = filePath & fileName
    fileName = "/" & URLEncodeJScript(fileName) ' For Azure in this format
    sUrl = blobUrl & fileName & sasToken

    Set adoStream = CreateObject("ADODB.Stream")
    adoStream.Mode = 3
    adoStream.Type = 1
    adoStream.Open
    adoStream.LoadFromFile filePath
 
    fileSize = adoStream.Size
  
    numParts = 5
    chunkSize = fileSize \ numParts
    If chunkSize = 0 Then chunkSize = fileSize

    DoCmd.OpenForm "dlgPRGBAR"
    Set progressForm = Forms!dlgPRGBAR
    
    Set xmlHttp = CreateObject("Microsoft.XMLHTTP")

    bytesSent = 0
    Do While bytesSent < fileSize
        If bytesSent + chunkSize > fileSize Then
            chunkSize = fileSize - bytesSent
        End If
        
        adoStream.Position = bytesSent
        ReDim fileData(0 To chunkSize - 1)
        fileData = adoStream.Read(chunkSize)
        
        Debug.Print "Chunk size: " & chunkSize & " Bytes sent: " & bytesSent

        xmlHttp.Open "PUT", sUrl, False
        xmlHttp.setRequestHeader "x-ms-blob-type", "BlockBlob"
        xmlHttp.setRequestHeader "Content-Length", CStr(chunkSize)
  
        Debug.Print "URL: " & sUrl
        Debug.Print "Content-Length: " & CStr(chunkSize)
        
        xmlHttp.send fileData

        If xmlHttp.status <> 201 And xmlHttp.status <> 202 Then
            Debug.Print "Error: " & xmlHttp.status & " - " & xmlHttp.StatusText
            MsgBox "Error: " & xmlHttp.status & " - " & xmlHttp.StatusText, vbCritical
            GoTo CleanUp
        End If
        
        bytesSent = bytesSent + chunkSize
        
        Dim IntValue As Long
        IntValue = (bytesSent \ chunkSize)
        If IntValue >= 5 Then
            IntValue = 5
        End If
        Set prg = Forms!dlgPRGBAR!CtlProgress.Object
        Set Complete = Forms!dlgPRGBAR!lblComplete
        prg.Max = numParts
        prg.Value = IntValue
        
        strComplete = Format((prg.Value / prg.Max) * 100, "##") & " % Complete"
        Complete.Caption = strComplete
        DoCmd.RepaintObject
    Loop

    adoStream.Close
    DoCmd.Close acForm, "dlgPRGBAR"
    
    responseStatus = xmlHttp.status
    If responseStatus = 201 Then
        MsgBox "File uploaded successfully!", vbInformation
    Else
        MsgBox "Error: " & responseStatus & " - " & xmlHttp.StatusText, vbCritical
    End If
    
CleanUp:
    On Error Resume Next
    If Not adoStream Is Nothing Then adoStream.Close
    Set adoStream = Nothing
    Set xmlHttp = Nothing
    Exit Sub
    
ErrHandler:
    MsgBox "An error occurred: " & err.Description, vbCritical
    Resume CleanUp
End Sub

Answer 1

根据 Azure 文档：

“Put Blob 不支持部分更新。要对块 blob 的内容执行部分更新，请使用 Put Block List 操作。”

不幸的是，我用这个方法没有成功。

与此同时，我探索了如何使用Append Blob 操作并成功地部分上传了文件。虽然这种方法有效，但我不确定它是否是正确的方法，特别是在文件上传期间合并进度条。

因此，我想澄清执行部分上传到Azure的适当方法。我应该使用 Put Block List 操作，还是可以使用 Append Blob 操作？

下面是演示 Append Blob 操作用法的片段： 注意：新的附加 blob 必须创建为容器中的新条目； 它无法覆盖任何现有的 blob。