当 url 正确时，VB.NET webrequest 返回 404

如何解决当 url 正确时，VB.NET webrequest 返回 404

我已经在这尝试了几个小时。我正在将此代码从 Access 2010 项目移植到 vb.net 我不知道这里会出现什么问题。

Visual Studio 2019，框架 4.7.2

    Dim data As Byte() = Encoding.UTF8.GetBytes(strBody)
    url = "https://rest.avatax.com/api/v2/companies/" & OE2019HomeForm.strAvalaraCompany & "/certificates/"

    Dim uri As Uri = New Uri(url)

    Dim request As System.Net.WebRequest = System.Net.WebRequest.Create(uri)
    request.Method = "Post"
    request.Headers.Add("40","Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)")
    request.Headers.Add("Authorization","Basic " & OE2019HomeForm.strAuth)
    request.Headers.Add("Cache-Control","no-cache")
    request.Headers.Add("20","application/json") 'this is the accept header
    request.Headers.Add("12","text/plain") ' content type
    request.ContentLength = data.Length
    



    Dim stream As Stream = request.GetRequestStream()
    stream.Write(data,data.Length)
    stream.Close()

    Using response As WebResponse = request.GetResponse()
        Using responsestream As Stream = response.GetResponseStream()
            Using reader As StreamReader = New StreamReader(responsestream)
                Dim webresponse As String
                webresponse = reader.ReadToEnd()
                MsgBox(webresponse)


            End Using
        End Using
    End Using

' 如果我在使请求变暗之前在下面添加一行，我会得到“'底层连接已关闭：接收时发生意外错误。'内部异常：Win32Exception：客户端和服务器无法通信，因为它们没有通用算法"

ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3

任何帮助都会很棒。

解决方法

这对你有用吗？把它放在靠近顶部的地方。

    ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls Or SecurityProtocolType.Tls11 Or
        SecurityProtocolType.Tls12 Or SecurityProtocolType.Ssl3 Or SecurityProtocolType.Ssl3



    ServicePointManager.ServerCertificateValidationCallback = Function(obj As [Object],certificate As X509Certificate,chain As X509Chain,errors As SslPolicyErrors) (True)