MSXML“系统无法找到指定的资源”

Question

我有一个使用 MSXML 发布 XML 文档的函数，该文档昨天开始失败，尽管没有对代码进行任何更改。函数如下：

Public Function PostFile(ByVal address As String, ByVal data As Byte()) As xmldocument
    Dim xmlHTTP As New MSXML2.XMLHTTP
    Dim response As New XmlDocument

    Dim xmlDoc As New MSXML2.DOMDocument

    Try
        xmlDoc.load(data)
        xmlHTTP.open("post", address, False)
        xmlHTTP.send(xmlDoc)

        If xmlHTTP.responseXML.xml <> String.Empty Then
            response.LoadXml(xmlHTTP.responseXML.xml)
            Return response
        Else
            Dim result As String = "<NO_Response><Error>the post succeeded to " + address + " but there was no responce returned</Error><Hint>Check FireWall Settings</Hint></NO_Response>"
            response.loadxml(result)
            Return response
        End If

    Catch ex As Exception
        'Error logging code removed

    End Try
    Return Nothing
End Function

XML 文档和传入的地址都是正确的 - 导致错误的行是 xmlHTTP.send(xmlDoc)。我在两台不同的机器上尝试过此操作，每次都出现相同的错误，并且还尝试重新安装 MSXML3，但没有成功。

抛出的异常是：

InnerException: Nothing 
Message:        "The system cannot locate the resource specified. "
Source:         "msxml3.dll"    
StackTrace:     "   at MSXML2.XMLHTTPClass.send(Object varBody)    at comms.HTTPHandler.PostFile(String address, Byte[] data) in D:\SCC\Main\Sender\Http.vb:line 42"

Answer 1

事实证明这是一个网络问题 - 我一开始并没有怀疑这一点，因为错误出现得如此之快，这并不表明端点有问题。问题在于已添加到防火墙（不要问为什么）的规则阻止与目标地址的通信。

Answer 2

如果你只是处理xml或者dtd处于离线状态，你可以使用：
xmlDoc.resolveExternals = False