Question

我试图在我的应用程序中连接一个api，此连接之前有效，但现在已停止。

如果我使用任何浏览器或邮递员应用程序，结果都是正确的，但是当我使用webrequest，webclient或Visual Studio中的任何方法时，我收到了超时错误。

我放置了用户代理，设置了超时时间，使用ssl，每次的结果都是相同的。

测试的终点是：

https://bittrex.com/api/v1.1/public/getmarkets

https://api.coinmarketcap.com/v1/ticker/?limit=1

当我使用类似google的网站进行测试时，此响应有效。

有什么主意吗？

使用WebRequestHelper更新

Imports System
Imports System.IO
Imports System.Net
Imports System.Net.Security
Imports System.Security.Cryptography.X509Certificates
Imports System.Text

Public Class WebRequestHelper
    Private m_ResponseUri As Uri
    Private m_StatusCode As HttpStatusCode
    Private m_StatusDescription As String
    Private m_ContentSize As Long
    Private m_WebException As WebExceptionStatus
    Public Property SiteCookies As CookieContainer
    Public Property UserAgent As String = "Mozilla / 5.0(Windows NT 6.1; WOW32; Trident / 7.0; rv: 11.0) like Gecko"
    Public Property Timeout As Integer = 30000
    Public ReadOnly Property ContentSize As Long
        Get
            Return m_ContentSize
        End Get
    End Property

    Public ReadOnly Property ResponseUri As Uri
        Get
            Return m_ResponseUri
        End Get
    End Property

    Public ReadOnly Property StatusCode As Integer
        Get
            Return m_StatusCode
        End Get
    End Property

    Public ReadOnly Property StatusDescription As String
        Get
            Return m_StatusDescription
        End Get
    End Property

    Public ReadOnly Property WebException As Integer
        Get
            Return m_WebException
        End Get
    End Property


    Sub New()
        SiteCookies = New CookieContainer()
    End Sub

    Public Function GetSiteResponse(ByVal siteUri As Uri) As String
        Dim response As String = String.Empty

        ServicePointManager.DefaultConnectionLimit = 50
        Dim maxFWValue As SecurityProtocolType = System.Enum.GetValues(GetType(SecurityProtocolType)).OfType(Of SecurityProtocolType)().Max()
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls11 Or SecurityProtocolType.Tls12 Or maxFWValue
        ServicePointManager.ServerCertificateValidationCallback = AddressOf TlsValidationCallback

        Dim Http As HttpWebRequest = WebRequest.CreateHttp(siteUri.ToString)
        With Http
            .Accept = "ext/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
            .AllowAutoRedirect = True
            .AutomaticDecompression = DecompressionMethods.GZip Or DecompressionMethods.Deflate
            .CookieContainer = Me.SiteCookies
            .Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip, deflate")
            .Headers.Add(HttpRequestHeader.AcceptLanguage, "en-US,en;q=0.7")
            .Headers.Add(HttpRequestHeader.CacheControl, "no-cache")
            .KeepAlive = True
            .MaximumAutomaticRedirections = 50
            .ServicePoint.Expect100Continue = False
            .ServicePoint.MaxIdleTime = Me.Timeout
            .Timeout = Me.Timeout
            .UserAgent = Me.UserAgent
        End With

        Try
            Using webResponse As HttpWebResponse = DirectCast(Http.GetResponse, HttpWebResponse)
                Me.m_ResponseUri = webResponse.ResponseUri
                Me.m_StatusCode = webResponse.StatusCode
                Me.m_StatusDescription = webResponse.StatusDescription
                Dim contentLength As String = webResponse.Headers.Get("Content-Length")
                Me.m_ContentSize = If(String.IsNullOrEmpty(contentLength), 0, Convert.ToInt64(contentLength))

                Using responseStream As Stream = webResponse.GetResponseStream()
                    If webResponse.StatusCode = HttpStatusCode.OK Then
                        Dim reader As StreamReader = New StreamReader(responseStream, Encoding.Default)
                        Me.m_ContentSize = webResponse.ContentLength
                        response = reader.ReadToEnd()
                        Me.m_ContentSize = If(Me.m_ContentSize = -1, response.Length, Me.m_ContentSize)
                    End If
                End Using
            End Using
        Catch exW As WebException
            If exW.Response IsNot Nothing Then
                Me.m_StatusCode = CType(exW.Response, HttpWebResponse).StatusCode
            End If
            Me.m_StatusDescription = "WebException: " & exW.Message
            Me.m_WebException = exW.Status
        End Try
        Return response
    End Function

    Private Function TlsValidationCallback(sender As Object, CACert As X509Certificate, CAChain As X509Chain, SslPolicyErrors As SslPolicyErrors) As Boolean
        If SslPolicyErrors = SslPolicyErrors.None Then Return True
        Dim Certificate As New X509Certificate2(CACert)

        CAChain.Build(Certificate)
        For Each CACStatus As X509ChainStatus In CAChain.ChainStatus
            If (CACStatus.Status <> X509ChainStatusFlags.NoError) And
                (CACStatus.Status <> X509ChainStatusFlags.UntrustedRoot) Then
                Return False
            End If
        Next
        Return True
    End Function

End Class

并使用它来调用课程

Dim url As String = "https://bittrex.com/api/v1.1/public/getmarkets"
    Dim uri As New Uri(url)
    Dim wr As New WebRequestHelper
    Dim resp = wr.GetSiteResponse(uri)

Answer 1

这是我如何连接到API的示例。

首先，根据您的JSON结果创建APIJSONViewModel，以存储id，名称，符号，等级，price_usd，price_btc等的值。

del kwargs['required']

使用webrequest API返回失败

1 个答案: