尝试通过.NET连接到Google Analytics API会产生“400错误请求”

Question

我正尝试从.NET应用程序连接到Google AnalyticsAPI。下面是代码，我想出了：

Public Function GetData() As String 
    Dim client As AssertionFlowClient = New AssertionFlowClient(GoogleAuthenticationServer.Description, 
                   New X509Certificate2("C:\Users\xxxxx\privatekey.p12", "notasecret", 
                        X509KeyStorageFlags.Exportable Or X509KeyStorageFlags.MachineKeySet)) With { 
                   .Scope = "analytics.readonly", 
                   .ServiceAccountId = "xxxxx@developer.gserviceaccount.com"} 
    Dim authenticator As OAuth2Authenticator(Of AssertionFlowClient) = New OAuth2Authenticator(Of AssertionFlowClient)(client, AddressOf AssertionFlowClient.GetState) 
    Dim service As AnalyticsService = New AnalyticsService(authenticator) 

    Dim profileId As String = "ga:xxxxx" 
    Dim startDate As String = "2013-02-15" 
    Dim endDate As String = "2013-02-20" 
    Dim metrics As String = "ga:visitors" 

    Dim request As DataResource.GaResource.GetRequest = service.Data.Ga.Get(profileId, startDate, endDate, metrics) 
    Dim data As GaData = request.Fetch() 

    Return data.ToString() 
End Function 

我的问题是，当我打这个方法，我上request.Fetch()一行“在发送直接消息或得到响应时出现错误异常“。内部例外说：“远程服务器返回一个错误：（400）错误的请求。”

这个错误显然非常含糊。根据Google's documentation of the error codes，400错误请求表明输入参数不知道。任何人都可以通过查看我的代码中的参数来诊断问题吗？否则，我怎么会开始追查我做错了什么？错误中几乎没有提供任何信息。

（至少我已经得到过验证的阶段......我认为）

Answer 1

从this answer广泛借鉴，我想出了解决的办法是这样的：

Imports System.Security.Cryptography.X509Certificates 
Imports Google.Apis.Analytics.v3 
Imports Google.Apis.Analytics.v3.Data 
Imports Google.Apis.Authentication.OAuth2 
Imports Google.Apis.Authentication.OAuth2.DotNetOpenAuth 
Imports System.Security.Cryptography 

Public Class GoogleAnalytics 

    Private _profileId As String 
    Private _service As AnalyticsService 

    ''' <summary> 
    ''' Creates an instance of the Google Analytics interface 
    ''' </summary> 
    ''' <param name="profileId">The Google Analytics profile ID, in the form "ga:123456789". This is *not* the same as the ID number used in the GA JavaScript to initialize the tracking! The number you want is in Google Analytics > Admin > (your profile) > Profile Settings.</param> 
    ''' <param name="serviceAccountId">The e-mail address of the Service Account that will access the API. These accounts can be generated from the Google API Console and then authorized by adding the e-mail address to the list of authorized users in Google Analytics.</param> 
    ''' <param name="privateKeyPath">The path to the private-key (.p12) file from Google.</param> 
    ''' <param name="certificatePassword">The password for the private key. Probably "notasecret".</param> 
    ''' <remarks>Once created, this GoogleAnalytics object can be used to make an arbitrary number of requests.</remarks> 
    Public Sub New(profileId As String, serviceAccountId As String, privateKeyPath As String, certificatePassword As String) 
     Dim cert As X509Certificate2 = New X509Certificate2(privateKeyPath, certificatePassword, X509KeyStorageFlags.Exportable Or X509KeyStorageFlags.MachineKeySet) 
     Dim client As AssertionFlowClient = New AssertionFlowClient(GoogleAuthenticationServer.Description, cert) With {.Scope = "https://www.googleapis.com/auth/analytics.readonly", 
                                 .ServiceAccountId = serviceAccountId} 
     Dim authenticator As OAuth2Authenticator(Of AssertionFlowClient) = New OAuth2Authenticator(Of AssertionFlowClient)(client, AddressOf AssertionFlowClient.GetState) 
     _service = New AnalyticsService(authenticator) 

     _profileId = profileId 
    End Sub 

    Public Function GetData(startDate As String, endDate As String, metrics As String, dimensions As String, Optional filters As String = Nothing) As GaData 
     Dim request As DataResource.GaResource.GetRequest = _service.Data.Ga.Get(_profileId, startDate, endDate, metrics) 
     request.Dimensions = dimensions 

     If filters IsNot Nothing Then 
      request.Filters = filters 
     End If 

     Return request.Fetch() 
    End Function 

End Class 

这是一个独立的类，可以使用，如下所示：

Dim analytics As New GoogleAnalytics("ga:12345678", "123456789012@developer.gserviceaccount.com", "C:\privatekey.p12", "notasecret") 
Dim data as GaData = analytics.GetData(DateTime.Now.AddDays(-30).ToString("yyyy-MM-dd"), 
             DateTime.Now.AddDays(-1).ToString("yyyy-MM-dd"), 
             "ga:totalEvents", 
             "ga:eventCategory,ga:eventAction") 

我发现这个洼最大的困惑是配置文件ID。这是而不是您传递给Google的Javascript跟踪代码的ID号;相反，这是您在Google Analytics>管理>（您的个人资料）>配置文件设置中找到的号码。希望这可以帮助别人！