我最终实施了原始问题中引用的选项一。
我在 VBA 中“分块”文件并将每个“块”传输到 Web 服务。我将解决方案的 VBA 部分基于此处找到的代码：Copy Large File by Chunk with Progress Notification。但是，我没有将其复制到文件系统，而是将其发送到服务器。
代码：VBA 土地
这是创建文件块的（丑陋的）VBA代码：
Function CopyFileByChunk(fileName As String, sSource As String) As Boolean
Dim FileSize As Long, OddSize As Long, SoFar As Long
Dim Buffer() As Byte, f1 As Integer, ChunkSize As Long
On Error GoTo CopyFileByChunk_Error
f1 = FreeFile: Open sSource For Binary Access Read As #f1
FileSize = LOF(f1)
If FileSize = 0 Then GoTo Exit_CopyFileByChunk ' -- done!
ChunkSize = 5505024 '5.25MB
OddSize = FileSize Mod ChunkSize
Dim index As Integer
index = 0
If OddSize Then
ReDim Buffer(1 To OddSize)
Get #f1, , Buffer
index = index + 1
SoFar = OddSize
If UploadFileViaWebService(Buffer, fileName, index, SoFar = FileSize) Then
g_frmProgress.lblProgress = "Percent uploaded: " & Format(SoFar / FileSize, "0.0%")
Debug.Print SoFar, Format(SoFar / FileSize, "0.0%")
DoEvents
Else
GoTo CopyFileByChunk_Error
End If
End If
If ChunkSize Then
ReDim Buffer(1 To ChunkSize)
Do While SoFar < FileSize
Get #f1, , Buffer
index = index + 1
SoFar = SoFar + ChunkSize
If UploadFileViaWebService(Buffer, fileName, index, SoFar = FileSize) Then
g_frmProgress.lblProgress = "Percent uploaded: " & Format(SoFar / FileSize, "0.0%")
Debug.Print SoFar, Format(SoFar / FileSize, "0.0%")
DoEvents
Else
GoTo CopyFileByChunk_Error
End If
Loop
End If
CopyFileByChunk = True
Exit_CopyFileByChunk:
Close #f1
Exit Function
CopyFileByChunk_Error:
CopyFileByChunk = False
Resume Exit_CopyFileByChunk
End Function
这是将块上传到服务器的引用 VBA 方法：
Public Function UploadFileViaWebService(dataChunk() As Byte, fileName As String, index As Integer, lastChunk As Boolean) As Boolean
On Error GoTo ErrHand
Dim blnResult As Boolean
blnResult = False
'mdlConvert.SetProgressInfo "Connecting to the web server:" & vbNewLine & _
DQUOT & server_title() & DQUOT
If InternetAttemptConnect(0) = 0 Then
On Error Resume Next
Dim strSoapAction As String
Dim strXml As String
strXml = "<?xml version=""1.0"" encoding=""utf-8""?>" & _
"<soap:Envelope xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"" xmlns:soap=""http://schemas.xmlsoap.org/soap/envelope/"">" & _
"<soap:Body>" & _
"<UploadZipFile xmlns=""http://something.com/"">" & _
"<zipBytes></zipBytes>" & _
"<index>" & index & "</index>" & _
"<isLastChunk>" & IIf(lastChunk, 1, 0) & "</isLastChunk>" & _
"</UploadZipFile>" & _
"</soap:Body>" & _
"</soap:Envelope>"
Dim objXmlhttp As Object
Dim objDom As Object
Set objXmlhttp = New MSXML2.xmlhttp
' Load XML
Set objDom = CreateObject("MSXML2.DOMDocument")
objDom.LoadXML strXml
'insert data chunk into XML doc
objDom.SelectSingleNode("//zipBytes").dataType = "bin.base64"
objDom.SelectSingleNode("//zipBytes").nodeTypedValue = dataChunk
' Open the webservice
objXmlhttp.Open "POST", webServiceUrl, False
' Create headings
strSoapAction = "http://something.com/UploadZipFile"
objXmlhttp.setRequestHeader "Content-Type", "text/xml; charset=utf-8"
objXmlhttp.setRequestHeader "SOAPAction", strSoapAction
' Send XML command
objXmlhttp.send objDom.XML
' Get all response text from webservice
Dim strRet
strRet = objXmlhttp.responseText
' Close object
Set objXmlhttp = Nothing
Set objDom = Nothing
'get the error if any
Set objDom = CreateObject("MSXML2.DOMDocument")
objDom.LoadXML strRet
Dim isSoapResponse As Boolean
isSoapResponse = Not (objDom.SelectSingleNode("//soap:Envelope") Is Nothing)
Dim error As String
If Not isSoapResponse Then
error = "Woops"
Else
error = objDom.SelectSingleNode("//soap:Envelope/soap:Body/soap:Fault/faultstring").text
End If
If error <> "" Then
ShowServerError error, True
blnResult = False
Else
Err.Clear 'clear the error caused in the XPath query above
blnResult = True
End If
'close dom object
Set objDom = Nothing
Else
GetErrorInfo "UploadFileViaWebService:InternetCheckConnection"
End If
ErrHand:
If Err.Number <> 0 Then
ShowError Err, "UploadFileViaWebService"
blnResult = False
End If
UploadFileViaWebService = blnResult
End Function
代码：C# ASMX Web 服务
现在，在服务器端，Web 服务方法接受一些重要参数。
- string fileName：文件名（每个chunk文件名相同）
- byte[] zipBytes：每个块的内容
- int index：索引（与 fileName 结合使用以提供文件系统上唯一的有序部分文件）
- bool isLastChunk：这是“我完成了 - 继续合并所有“块”并自己清理”标志。
int 索引和 bool isLastChunk。借助 VBA 世界提供的上下文，我知道如何保存这些文件块中的每一个，然后在 isLastChunk 标志为真时将它们组合起来。
/// <summary>
/// Accepts a chunk of a zip file. Once all chunks have been received, combines the chunks into a zip file that is processed.
/// </summary>
/// <param name="fileName">Name of the file.</param>
/// <param name="zipBytes">The collection of bytes in this chunk.</param>
/// <param name="index">The index of this chunk.</param>
/// <param name="isLastChunk">if set to <c>true</c> this is the last chunk.</param>
/// <returns>Whether the file was successfully read and parsed</returns>
/// <exception cref="ParserException">An error occurred while trying to upload your file. The details have been written to the system log.</exception>
[WebMethod]
public bool UploadZipFile(string fileName, byte[] zipBytes, int index, bool isLastChunk)
{
try
{
const string ModuleRootUrl = "/Somewhere/";
string folderName = HostingEnvironment.MapPath("~" + ModuleRootUrl);
string fullDirectoryName = Path.Combine(folderName, Path.GetFileNameWithoutExtension(fileName));
try
{
if (!Directory.Exists(fullDirectoryName))
{
Directory.CreateDirectory(fullDirectoryName);
}
string pathAndFileName = Path.Combine(fullDirectoryName, AddIndexToFileName(fileName, index));
using (var stream = new MemoryStream(zipBytes))
{
WriteStreamToFile(stream, pathAndFileName);
}
if (isLastChunk)
{
try
{
MergeFiles(fullDirectoryName, fileName, index);
// file transfer is done.
// extract the zip file
// and do whatever you need to do with its contents
// we'll assume that it works - but your "parsing" should return true or false
return true;
}
finally
{
DeleteDirectoryAndAllContents(fullDirectoryName);
}
}
}
catch
{
DeleteDirectoryAndAllContents(fullDirectoryName);
throw;
}
}
return false;
}
这是将每个传入块写入文件系统的 C# 代码：
/// <summary>
/// Writes the contents of the given <paramref name="stream"/> into a file at <paramref name="newFilePath"/>.
/// </summary>
/// <param name="stream">The stream to write to the given file</param>
/// <param name="newFilePath">The full path to the new file which should contain the contents of the <paramref name="stream"/></param>
public static void WriteStreamToFile(Stream stream, string newFilePath)
{
using (FileStream fs = File.OpenWrite(newFilePath))
{
const int BlockSize = 1024;
var buffer = new byte[BlockSize];
int numBytes;
while ((numBytes = stream.Read(buffer, 0, BlockSize)) > 0)
{
fs.Write(buffer, 0, numBytes);
}
}
}
这是合并所有 zip 文件“块”的 C# 代码：
/// <summary>
/// Merges each file chunk into one complete zip archive.
/// </summary>
/// <param name="directoryPath">The full path to the directory.</param>
/// <param name="fileName">Name of the file.</param>
/// <param name="finalChunkIndex">The index of the last file chunk.</param>
private static void MergeFiles(string directoryPath, string fileName, int finalChunkIndex)
{
var fullNewFilePath = Path.Combine(directoryPath, fileName);
using (var newFileStream = File.Create(fullNewFilePath))
{
for (int i = 1; i <= finalChunkIndex; i++)
{
using (var chunkFileStream = new FileStream(AddIndexToFileName(fullNewFilePath, i), FileMode.Open))
{
var buffer = new byte[chunkFileStream.Length];
chunkFileStream.Read(buffer, 0, (int)chunkFileStream.Length);
newFileStream.Write(buffer, 0, (int)chunkFileStream.Length);
}
}
}
}